What are the benefits of 700c23 tires? 23s come on almost all new road bikes, and tire selection is much better for 23s than other tire sizes at most shops.

The benefits of 25s and 28s are a better ride, more traction, and are more flat resistance than 23s. How noticeable is the difference in rolling resistance (in fact, some people claim that running slightly lower pressures allows for better rolling resistance on most 'real-world' surfaces)?

Are narrow tires only for time trials racers, or do they have advantages for the other 99% of riders?

WIDER TYRES ARE FASTER

Every study on rolling resistance (including ones carried out by the leading tyre manufacturers) demonstrates clearly that wider tyres have LOWER rolling resistance and not just at the same pressure. This is also verified by many people (including myself) who use 25mm-28mm and much wider tyres on a regular basis and will never go back to anything narrower.

For vast majority of road cyclists there isn't a single rational reason (other than time trailing) for using 23mm tyres if the same model is available in 25 or 28 or wider width. On some bad roads (e.g. UK) it's actually unwise and dangerous to bounce around on such narrow piece of rubber.

There are several reasons why the myth of "fast" narrow tyres is still alive and kicking.

23mm is everywhere from the adverts, your local bike shop, cycling club to the TdF.
It's inconceivable for most of people to think that so many people around them could get it so wrong. Most of folks just go with the flow and don't ask questions.
People believe that they can "feel" rolling resistance and if narrow tyres are pumped up to its usual 100-120PSI it feels fast. You can't feel rolling resistance but you have to methodologically measure it with a power meter of some sort. Firmness and discomfort doesn't translate to speed, quite the opposite.
It's a common belief that rolling resistance is just a function of
a contact patch and the lower the contact area the faster the tyre is. The facts are that the shape of a contact patch and volume are more important than the total area.
People assume that rolling resistance is just about hysteresis (friction/resistance with the tyre itself) and nothing else. They are unaware of (or ignore) "suspension losses"
which occur on some less than perfectly smooth roads (most) and are about energy lost on lifting the rider/bike on imperfections of the surface.
For the same reason but on a much larger scale most of experienced mountain bikers with half brain run their tyres at a low pressure to go faster as even small obstacles (even bumpy field or gravel) are absorbed more effectively with less energy lost.
People confuse assumptions and beliefs with hard evidence. How many times you've read/heard: "Surely there is a reason why 23mm tyres are so popular..." "Surely if the pros use 23mm tyres..." Assumptions don't prove anything.
Some people (like one of the posters) have tried wider tyres and they found them slower.
Only comparing identical tyres in different sizes make sense and it's pretty obvious that a 23mm Michelin Pro3 is going to be faster than a 28mm Gatorskin due to a different design. Also the difference in speed that 2-3mm difference offers is most likely very small and can be only measured during repeated tests with a power meter at various pressure levels to find each tyre's sweet spot.
Many people have never tried anything wider as their frames/forks don't have enough clearance and more sensible and practical bikes taking wider tyres aren't "good/fast" enough for them or don't look right. They've never tried any fast wider tyres like Rivendell Jack Browns 33.3333mm or Schwalbe Kojaks 35mm or some fast 650B tyres. They have never run a pair of custom shaven completely bold 26x2.00 Schwalbe Furious Fred 120TPI 3oog mountain bike tyres on the road. It could be an eye opener.
Narrow tyres can be pumped up to higher pressures and higher pressure equals more speed. That's incorrect. As you increase the pressure, rolling resistance is going down but then at a certain point starts climbing sharply due to reduced ability of the tyre to conform to the non-perfect road surface (suspension losses). Even on a track/velodrome you won't benefit from 200PSI.
For every tyre width/volume, road surface and the rider's weight combination there is always an optimal (fastest) pressure. High pressure on its own means absolutely nothing.
The pros use it!
This the favourite argument of the defenders of status quo. You can't argue with it, can you?

Well... the pros ride at completely different speeds and therefore the aero benefits are probably more significant than rolling resistance. An average amateur rider would be naive to worry about the air flow differences between 23-28mm tyres.
Weight is also crucial as winning the stage / future career can be decided on a single climb. Again people worrying about the weight difference of several grams (rotating or not) may be slightly over-anxious.

The pros used to use 19mm tyres too in the past and now they are very slowly migrating to 25mm tyres. Were they wrong at the time, or are they wrong now or they will be wrong in the future? What if they discover that 28mm is even better? Will everyone be blindly following them?
The truth is that they are as guilty as you and me of being humans and use stuff that feels right and also aren't immune to peer pressure.

Road cycling community tends to be very traditional, conservative and protective of the status quo as I've experienced on other forums and in real life but for being open-minded and embracing "new" things can greatly benefit one's cycling.

I think because 23mm tires typically have higher pressures and a larger contact area with the pavement, reaching high speed is easy but maintaining speed is hard.


I can't shift to the largest chainring Please help. The derailleur seems to be fine, I'm suspecting the handle. I can't shift to the largest chainring at the front, it drops back to the second largest ring as soon as I release the shifter. I need to keep the pressure on the shifter in order for the derailleur to maintain its position on the largest ring, or else it will drop back to the second one.

Let’s quickly review how your bike shifts. Your front derailleur rests in the small ring position. When you move your left shifter to the big ring position, you pull cable, and that pulls your FD to the outside position. The same principle applies to the rear derailleur, which rests on the smallest cog, and gets pulled to the big cog. There's a ratchet inside each shifter that controls the amount of cable it pulls per shift.

The thing with cables is that they stretch over time. So, there may be a bit of slack in the cable, and your shifter isn't pulling as much cable as it should. This means your front derailleur doesn't move as far outward as it should. This happens with new bikes - I distinctly remember this happening on my first bike, and I was having trouble shifting both front and rear. The same issue will probably happen to your rear derailleur.

If this is a new bike, chances are the bike store asked you to come in after a few weeks for a free tune up - they’d adjust your cables. You can take them up on it. Alternatively, you can adjust your bike yourself. It likely seems complex at first, but the mechanisms are fairly simple once you understand them. Park Tools has a nice post explaining how to do this, and the post also has an embedded YouTube video. If it’s just cable stretch, you will only need to twist the cable barrel adjuster, and you can skip the bits about setting the limit screws.

Basically, righty tighty (I.e. turn clockwise to tighten) on almost all bolts on the bike. When you turn the cable adjuster clockwise, you push the barrel further in, which slackens the cable. Turn it anti-clockwise instead to tighten the cable.

If you have gone and adjusted your limit screws, you’ll need to re-adjust them carefully. The symptoms you describe can be explained by new bike and cable stretch, so I will not describe the limit screws right now.

(A previous version of this answer wrongly described what to do for just the rear derailleur. The title of the post initially said "cog", which is standard terminology for the gears in the back. We would say "chainring" to mean the rings on the crank, i.e. the front. The principle is the same, it's just that cable stretch affects each derailleur in a different direction.)

An additional cause can be a partially-frayed inner cable.  This is known to happen inside the mechanism of many types of brifter (integrated road bike shifter).

Curiously, pod shifters/trigger shifters have a much smoother path and don't tend to stress the cable as much.  This is partially because a brifter combines brakes and shifters, and every braking action also flexes the gear cable head.

Over time the gear cable kinks, and can break strands, until at worst it will separate completely.   As the strands break, the cable's effective length increases, which can cause that "not quite far enough" effect you're seeing.

Upshot Check your inner cables and replace as required.

Best practice is to replace all inner cables every 10,000 km or bi-annually, whichever is first.  Also do it a month before any big race/ride events so the new ones have a chance to settle in.

If the cable does break off, getting the head out can be difficult.  Its even hard to pull the cable if a strand has snagged on something.

  this is a motorbike clutch cable, but the effect is similar.


Do any bike sharing schemes provide a way to rent or share helmets along with the bikes? Do any bike sharing schemes provide a way to rent or share helmets along with the bikes, either in a kiosk or through an arrangement with local businesses?

None of the schemes that I've used (London, Vienna, Boston) or am aware of provide them, and in most that I'm aware of it is rare to see helmets in use at all, despite the fact that most recommend them and in several cities riding without them is illegal.

Have any of the cities that have cycle hire schemes come up with a convenient way to provide helmets along with the bikes in a way that's consistent with the "use and forget" philosophy of the schemes?

In Melbourne, we have a bike share scheme. You can buy helmets for $5 from various outlets and then return them for a refund of $3 (they are then cleaned and reused).

Despite this, many people are saying that Australia's compulsory helmet laws are responsible for the lack of success of the bike sharing scheme.

I wouldn't think that most of these bike rental places would include a helmet, mostly because most people consider any piece of head gear a personal item not to be shared with others. There is hygiene involved with a those that may have worn the helmet prior to you.


Do I have a genuine GT frame, even though it's not engraved or stamped with the GT logo? How can I know whether the bike frame I have is a genuine GT? I found the serial number u31036009 on the bottom of the hub. It has no GT logo stamp or engraving anywhere on it. Could it still be genuine?

My awnser is that it COULD be a real gt,but probably one made strictly for racing(not publicly sold) or a prototype made by some one working for the company at the time. My big brother once had a profile complete bike(When they only sold bars to the public) because he was racing at the time and it had no serial numbers or logos/stickers. Its because it was a prototype and a R/D guy asked him to check it out and give him feedback about it. He then gave it to my brother when he was finished with testing. And when my brother told his friends they laughed at him saying he was lying because "They only sell handlebars". No body would believe him except me( I was there) so It could be some reason they didnt put logos on . Probably a prototype if not,could be a fake

I don't think gt ever made a bmx frame, but should it have, it would be one of a kind to celebrate something, for instance a racer that finished first. So they designed it for a purpose. I would advice you to get informed whether or not this is a gt bmx frame.


Compatibility of Shimano Ultegra and Sora components My road bike has an Ultegra groupset, but some parts need replacement (chainrings, chain, and cassette). The chain is worn out, the cassette is sliding with a new chain, and the chainset is also worn out. Can I keep my 3-9 derailleurs and mount new Ultegra chainrings with a Sora cassette (9) and a Sora chain to save some money, or should I keep riding and mount ultegra chainrings, chain, and cassette when they are fully worn out?

Most groupset parts don't wear out on a predictable replacement schedule. Derailleurs, brakes, cranks, and brifters should last for a long time, barring unusual wear or crashes. And I hate to say it, but if you do get to the point where you want to replace those parts, it might be cheaper to buy a new bike.
Modern Sora and Ultegra chainrings are 4-bolt, and are completely incompatible with your 5-bolt Ultegra cranks. You could replace the entire chainset (aka crankset), but a modern Sora chainset will be incompatible with your bottom bracket (your Ultegra chainset uses a separate BB; the Sora and other higher-end Shimano chainsets today integrate the spindle into the left crankarm), so that would need to be replaced too. You might be better off looking for NOS Ultegra rings.
Sora-grade chains are lower quality (less precise spacing between rivets), which will wear out the cassette and chainrings more quickly.
The Sora cassette will work.


Can I ride home with a broken spoke? I noticed a wobble in my back wheel while commuting in this morning. Broken spoke. Is this a problem that I should take care of before my 7 mile commute home, or can I pick up a spoke and repair it at home?

Yes you can ride home with a broken spoke. I'd probably unscrew the spoke from the nipple before doing so, so that it doesn't wobble around and get caught in other bits of the bike. Bike wheels are wonderful things that can easily put up with having a few spokes missing.

I would say yes but your chancing running it through you liner and into your tube. If it's just one broken spoke and you don't have far to go, you can bend/wrap it around the spoke next to it. Just don't bounce around a lot.


Mounting the front light on the frame instead of the fork or the handlebar? I've had my front light mounted on the handlebar for the last 4 years or so. I never liked the bulky look and more importantly, how it jumps around in a response to my handlebar movements (if I'm on a rocky road avoiding obstacles and people are walking in front of me, it unnecessarily scares them).
So to have the front light point in the general direction of the bike instead, I'd have to mount it to the front of the frame somehow, like this:

Problem is, I can't find any lights on sale that'd be compatible. I even found wheel axle mounted, but not frame mounted. Is there a reason? Is this a bad idea?
This discussion mentions how frame direction lags behind where you're looking at, but I won't be cornering this fast in these seemingly extreme conditions, so shouldn't be a problem.

The light is better on your handlebars or fork than on your frame - the frame lags and always points at some tangent to where you're going while turning, so either you need a really wide beam, or you have to ride into the dark.
Fortunately there are solutions, and some of them are pretty vintage.

Steerer mount.   In the days of threaded headsets, there was a stack of anti-rotation washers needed.  It was common for one of these to be extended out the front and upward, to support a "bicycle lantern"
As time went on these changed from oil lanterns to battery powered by two D cells.

this last one is a particularly vintage unit, but shows how it is mounted on the bike, below the threaded stem's retainer nut.

A variation on the above is to mount the lamp from the front wheel's brake bolt.
 Downside of this is its getting quite low and can be obscured by wires.  Also many brakes don't have bolts long enough to go through more thickness.  However if your bike has a cantilever, V, or disk brake, then this hole is either spare or used only for a mudguard/fender.  Worth considering.

There are a ton of options for mounting things under the bars too, which helps clean up your working area.  Risk here is that some lights are built with a certain intentional beam pattern, and flipping them will light up other road users in an non-legal manner.

If you have to mount your light to your frame, there are two ways to do it.

Secure a longer flashlight/torch to the side of your top tube, such the front lens area is forward of the head tube.  Downside, a torch makes for a bad headlight because the beam pattern is wrong.

Get a gopro handlebar mount, and put it around your headtube with the clamp between the top and downtubes.  This will let you use some kind of gopro to your-light adapter.
I use this for my gopro on an older road bike, and the footage is really directional, makes me look quite pro while riding.

this is what I found, it allows to move my hadlebar light (Fenix BC30R) to the frame of the bike.
https://www.amazon.de/-/en/Rixen-Kaul-Light-Holder-Bracket/dp/B00INTRNN2/ref=sr_1_2?dchild=1&keywords=klickfix+lampenhalter&qid=1615755807&sr=8-2
or
https://www.amazon.com/Front-Light-Extender-archmount-Extension/dp/B01GMK5D7Q


spinning handle bar grips - can it be dangerous I did have spinning handle bar grips on my bike. I have now replaced them with some specialized lock on grips i.e. bolted on.

For example if you're cycling on the road, could spinning grips upset your balance to the extent the bike washes out from beneath you?

This may be a stupid question but I don't want another trip to A&E and 6 stitches to my chin.

In my humble personal opinion, I don't see it being an issue unless you are in an extreme situation such as downhill or freeride stuff, it which case it could result in a crash. Even then I feel like a good lock on grip is just fine and when tightened I have never spun one.

According to WTB is can be dangerous though as their newest line of grips is aimed at stopping exactly that.

  Rotated grips. They end rides, dreams, and winning seasons. So, we solved the problem. In doing so, we also created a more comfortable grip, which utilizes a tapered inner-grip cylinder that interfaces directly with PadLoc-ready handlebars to eliminate rotational slippage entirely. It’s so unique that we applied for US and international patents. And yes, it rules – riding hard with comfort should have been figured out long ago – fortunately, we nailed it. Ride it to believe. Never go back. Locked comfort perfected.

Although i can see the comfort side of their design i feel like they have created a solution to a problem that wasn't a very big one.

With that said i do feel like spinning grips could be potentially dangerous in the "perfect storm" sort of circumstance, especially with it in mind that if they can spin they could potentially slip off as well if your really yanking on them in the turns...

However, under normal everyday commuter and similar conditions I don't think it is something to stress about unless they are loose to the point of spinning freely. Lock ons are proven to work, as is using hairspray between the grips and bars for a little extra grip.

I am sure that there are cases where ridiculously easy spin of the handle could be problematic. E.g., pulling hard on the brake lever while your thumb is not optimally hooked on the handle for whatever reason. If the handle is loose, it could rotate and you could somehow slip or not be able to transfer enough force to the lever.

Besides, there are occasions where I grip the handles quite strongly during mountainbiking while having one or two fingers on the brake lever in "ready position"; if the handle would rotate, I would not have an immediate feeling of what the bike does. It would likely confuse me when I am cruising along near my limits.

EDIT: removed the mention of chalk.


Are there any route planning/mapping apps or websites that can show a chart of cumulative ascent? Strava and Ride With GPS both show elevation charts, but they show elevation at any particular point in the ride, i.e. on a circular route with 2000m of climbing the charts will go up and down but they will always finish at the same elevation they started.
I'm looking for a way of showing a chart that adds up the ascent/climbing as it goes, so the same route would have a chart that always increased and ended up at 2000m. Is there an easy way to do this for any given GPX file?

Starting from any route-planning tool that can export GPX, you can do this on my website. It's more about the mapping and planning rides for Veloviewer Explorer, but I've added a graph showing cumulative ascent below the map that displays multiple GPXs. Multiple rides can be plotted, automatically colour coded to match the map.  Processing is handled on your own machine using javascript; nothing is uploaded to my server.  Just drag and drop the GPX onto the map.

The code is also available at GitHub under the most permissive of licenses.
Originally I took this as an interesting challenge to my spreadsheet skills.  The spreadsheet I created (xlsx, original LibreOffice ods) takes a GPX file pasted into one sheet, and displays on another sheet a graph of cumulative elevation, as well as calculating the distance at which you've done half the climbing.
It doesn't attempt to parse the XML of the GPX file; everything is done in cell formulae.  This means that each track point is assumed to look like this and to not have a timestamp (so it works for RideWithGPS and Strava routes, but not Komoot).
<trkpt lat="51.53166" lon="-2.4620100000000003">
    <ele>57.870000000000005</ele>
</trkpt>

This is what the output looks like:

I'll probably write something in javascript as well, and host it; that would allow the route to be displayed on a map.

Strava will give you a breakdown of YTD figures on distance, time and elevation.

For this year I’ve covered 9600 ft across all rides, as you can see I don’t go out my way to find hills.
You can find it under your profile settings.
If your handy with spreadsheets you could easily track elevation using data from apps, you could do this via api calls if the 3rd party app allows users access to API.
If they don’t allow API you could still easily log your own data into a spreadsheet.
Alternatively look into reading the fit or tcx files using a suitable editor and pull the elevation data directly from these.
Looking back at Strava it will also give you your elevation gains under each ride / activity.

You can see the highest elevation was less than 400ft but over the course of the ride I covered 837ft.
For simplicity you really can’t beat Strava though for having all that you need though.


How to avoid running over animals whilst cycling on a canal at night? I commute on a towpath in Hertfordshire, England and there is ample amount of wildlife about.

During the day it's fine, I can see ducks, squirrels and rabbits in time and slow down if I need to.

However at night it seems to be a problem as I occasionally have close calls with particularly what I believe are squirrels and rabbits trying to cross the towpath as I'm approaching.

I believe they see me rather too late sometimes and despite my front lights and intermittent signalling with the bell I've not been able to mitigate that. It goes without saying that I see them especially late. Particularly problematic are blind sports just before a turn. It doesn't help that often there are no other light sources apart from my lights.

Has anyone run into a similar problem and has any tips?

My commute brings me through a park with a lot of rabbits (or similar animals, not a zoologist here) and it has been rather close a few times ...

I use a head lamp when driving there at night for two reasons:

It allows me to see through turns much better
The eyes of animals reflect directly back at you, which helps to see them a little earlier

All that does not help when they jump out of the shrubs directly in front of you. It doesn't happen a lot, but I have seen dead rabbits on the path a few times. (No dead cyclists yet)

Easy - stop treating my home as a racetrack and you won't hit anything. In 30 years of cycling the towpath I've never hit anything and I don't very often use lights.


Quick Release for Accessories Is there a way I can make my bolted-on accessories quick release?
I'm looking for something that allows quick removal & replacement of accessories like lights or screens that come with a hex bolt, philips head or similar fastener similar to the mount on this bell:
One possibility I thought of would be cutting a hole through the front of the bottom part of the plastic mount, a thumbscrew that could slide in & out of the hole and a washer or nut on the bottom to prevent the screw from slipping out of the hole unintentionally. I'm not sure how practical that would be though.

I think in most cases there's going to be a better solution than actually doing this, but wing bolts are one way to go.

Since most of the accessories brackets in question have recessed holes for the bolts, you may need a spacer of some sort in between, like a presta ring.

You have two paths - either take your accessories with you, or make them hard to remove.
Make everything removable
Removing the bolts for every item every time will get old fast.  And after some number of cycles you'll have worn down the threads to the point they won't be as tight, or you'll wear out the screwdriver fitting (hex/philips/slot/torx)
You could change all your items for some that have two-part mounts, with a way to unclip them and leave bare plastic fittings on your bars, like lights used to be constructed before rubber bands became common.
How far down this path is reasonable?  Someone could steal your QR wheel, so do you take that?  What about your QR seatpost?  Pedals are only one undo away from being separated too.  Take it far enough and you're locking up a bare-frame and taking everything else with you.  Which leads to the ultimate of simply taking the whole bike - aim to own a folding bike and keep it with you rather than leaving it in a stand.
Make it hard to remove accessories.
High temp thread lock in the threads is an excellent way of making a bolt hard to remove.  The downside is adjustments later will be difficult or impossible because the thread lock will not release until it hits a high temp, hotter than the bike and plastic parts can stand.   Even copious amounts of super-glue (cyanoacrylate glue) can do the same.  Additionally you can intentionally strip the screw's head.
It has also been done to drop a ball bearing in the screw hole and use glue or grease to hold it there.  Removal can be done with a magnet or a sharp pick, neither of which the average lightfinger would carry.
If your accessory is held on by a metal bracket, then brazing or soldering or welding might be a good solution.
This does nothing to stop vandalism sadly.   Also, my suspicion is that a thief would prefer to take the whole bike rather than faff about stealing your bell or reflector.  Those parts aren't valuable to a thief.
Don't have desirable parts visible
My favourite alternative solution to reflectors is DOT tape.  Essentially reflective stuff that you stick directly to the bike, and it does the job of being a reflector without being stealable.   Red in the back, white in the front, Yellow from the side.
A bell is not compulsory here, so I don't have one thus it can't be stolen.


What causes the threads on bike pedals to become stripped? Is there something I can do to prevent my bike pedals from wearing out? And what causes the threads on a bike pedal to wear out?

I have a 4 year old Raleigh road bike with just regular open pedals. After 300 miles of riding, I had to replace the pedals because one of them broke off when the threads on the arm that the pedal screws into wore out.

The bike repairman offered to send the pedal out to be re-threaded but that would have taken a week and cost more than just replacing the pedals.

Any suggestions or recommendations?

It probably means that the pedal was never installed correctly: either it was not tightened enough or it was cross-threaded.

It's actually not that hard to install a pedal incorrectly. If you miss perfectly aligning the threads, it's called cross threading. It's possible to cross thread the pedals and still have them feel like the pedal look like it is installed properly.

However, if you look closely, you'd see that the pedal isn't perfectly perpendicular to the crank. When you pedal, you'll feel a pop as the pedal goes around when your foot crests and the pedal (due to not being parallel to the crank) has to change orientation.

Over time movements of the pedal relative to the crank will slowly strip out the threads on the crank, on the pedal, or both.

I could speculate that your raleigh may have been purchased at a department store, and that it wasn't assembled by a professional. They didn't install the pedal correctly.

Generally, the bolts one should use are titanium bolts. They do not wear out easily and they will last for ages! The only downside is that they may be quite costly, meaning about 6 euros per pair. The pedals' threads probably were damaged because there was not enough grease or good quality grease on them. This causes the two threaded parts joined together to have friction and day by day them getting destroyed.


Considering purchasing a slightly used Hollandia Evado e-bike... couple minor questions I am on the verge of purchasing a Hollandia evado e-bike.  It would be for me, a male, though the previous owner was a female.   From what I could learn myself, the "step through" design is used by both sexes, and this bike is considered unisex.  Here are my two questions:

Is it true that this is a unisex bike?

Is the make and model considered a "hybrid," or, if not, can I at least ride it on pavement as well as the bike trails?

Thank you in advance!

Is it true that this is a unisex bike?

Step-through frames are indeed considered unisex as they are mostly seen in bikes used as 'way of locomotion' rather than 'sport device': if you are not wearing clothes that are suited for cycling (not only skirts for women, but also tight trousers for men or suits), you gain a lot in comfort by having a step-through frame. They are also popular among people who do not are not "flexible enough" to step in a classical frame (typically older persons).
For other kind of frames, the difference is mostly linked to cultural norms/marketing than physical properties of the bikes. Bikes were introduced in a time where women were required to wear long skirts, so different frames were designed for that reason. Nowadays, if you take a bike of the same size and the same model in men and women version, besides the frame and the colours, at best you'll have a different saddle and smaller handles on the handle bar on the women bike (which are very easy to change).

Is the make and model considered a "hybrid," or, if not, can I at least ride it on pavement as well as the bike trails?

It seems from the pictures (and the name) that it would a bike that would be perfect in a "dutch environment": on a flat environment and paths on a good state. There are several elements that will make it unsafe/uncomfortable on uneven/rough surfaces:

The general geometry is more tuned towards comfort than control.
There are elements that are not designed for rough terrains: frame (not only because it's a step-though, but also because of the sizing of the tubes), the adjustable stem.
The motor in the hub of the wheel is not optimum in rough terrains, and can make punctures repairs more difficult (they are less efficient at low speed, have lower torques as they cannot take advantage of the gearing);
The gearing that might not have enough range for steeper hills
The tires don't have the right profile;
V-brake don't perform well in wet conditions and in sustained brakings;
...

Is it true that this is a unisex bike?

Every bike is a unisex bike. I think you'll find that most high quality bikes have a diamond frame whether used by a male or a female. The reason is that diamond frames are light in weight and extraordinarily durable.
A step through frame, in contrast, is heavy and will fail easily for all but the lightestweight riders riding on low pressure wide tires who never ride over harsh obstacles at high speeds.
The reasons for creating a step through frame can be divided to two:

It's easier to mount the bike
It's possible to ride in a skirt

Only reason (2) would make it a female bike. For example, for someone who has a physical disability making it hard to lift a leg over the diamond frame, the only option might be to use a step-through frame. For some people, the disability might make it impossible to ride the bike, but for many people, the disability might only make it hard to mount a traditional diamond frame.

Is the make and model considered a "hybrid," or, if not, can I at least ride it on pavement as well as the bike trails?

Every bike, even a mountain bike, can be ridden on pavement. Most mountain bikers have to ride quite a lot on the pavement before finding their way to the mountain bike trail. A mountain bike would not be ideal for only riding on pavement, though, due to the inoptimal aerodynamics and the high rolling resistance tires.
Every bike, even a road bike, can be ridden on bike trail. However, for gravel trails that are wet it might be a good idea to use 32mm wide tires. Some road bikes make it impossible to fit a tire wider than 23mm or 25mm -- but such bikes should be ignored anyway. The rest of the bikes, the ones having reasonable tire clearance, can be perfectly finely ridden on gravel trails.
Looking at the Hollandia Evado bike specs, it looks like a comfort/utility riding oriented electric hybrid bike. The main features that make it not suitable for most active cyclists are the riding position (too inaerodynamic for high speed), the step through frame that weighs a lot and fails in no time, the front electric drive (it will make it hard to fix a front puncture and will spin on steep hills with little traction, causing you to crash -- most quality e-bikes have mid-drive), and the cheap suspension fork. Most active cyclists avoid cheap suspension forks, either using a rigid fork or a very high quality suspension fork when suspension is absolutely needed (expensive!). Also the saddle on this bike looks heavily inoptimal for active riding (too wide), but it's an easy job to change it to a reasonable saddle.


How can I look unsafe to a car driver but be safe This research seems to show car drivers give you more space if they think you are more likely to do something unpredictable.

It claims that where a cycle helmet often results in drivers giving you less space.

So how I make a driver think I am not a safe cyclist without being unsafe.

Is this the reason why the cyclists I always saw in Cambridge without lights never seem to get knocked of their bikes, but “safe” cyclists I knew with good lights and reflective jackets etc did sometimes (not often) get knocked of their bikes?

Direct link to research and a blog post by the researcher.

Try not hugging the edge of the road, drivers will be more tempted to squeeze past through smaller gaps if you're right at the edge. Instead ride about 1/4 of the way across the lane, it might p*** off a few drivers, but it will make them think twice about squeezing past with overtaking traffic / parked cars / etc.

Giant Tolkien-dwarf style Axe strapped to your back?

An assault rifle slung over one arm?

Waving a sword around your head ?


Damaged Carbon Steerer Tube, repair/replacement? I cracked the top of my 2007 Schwinn 1 1/8 fork black label steerer tube.
What kinds of repair are available? Should I just buy a new name-brand carbon fork, e.g., Canondale, GT, Trek on ebay?

The standard line from the carbon repair shops is they don't do forks because new ones are a lot cheaper. My understanding is that safe steerer repairs are technically possible in a lot of cases, so if you want to go nuts or if the original is unique in some way you might be able to find someone to do it, but it's probably not worth it. I think in practical terms, the real problem is that a lot of the time if one part of a carbon fork is destroyed, the rest might be pretty well-loved also.
The usual approach is to measure the axle-to-crown and offset dimensions of the original and go shopping for something close. Among carbon rim brake road forks, there's not a lot of variance. A number of companies make what are essentially repair forks for this kind of situation.

Should I just buy a new name-brand carbon fork, e.g., Canondale, GT, Trek on ebay?

The definition of insanity is doing the same thing over and over again and expecting different results.
If you observed a certain material to be inadequate for a fork steerer tube, why are you going to purchase a new fork having a steerer tube made of the same material?


Spring side fork grease First post here and also first time servicing my forks, which are 2006 Marzocchi Dirt Jam Pro.

I was wondering if anyone knows what kind of grease i should be using for the spring in the left leg. The manual I have been going off just says "smear the left spring with the recommended grease" but doesn't actually detail the recommended grease.

What is the recommended grease?

The grease on a coil spring is purely to reduce friction between the spring and the fork leg/stanchion. The choice of grease is non-critical beyond ensuring that it is compatible with the existing grease (or you clean the fork thoroughly to remove the old grease) and that it will not damage the seals. Natural rubber seals can be damaged by petroleum based greases however most fork manufacturers appear happy to use petroleum based calcium greases such as Buzzy's Slick Honey so this does not appear to be of much concern in practice.

The 2006 Marchozzi product manual does not mention or recommend a specific grease type. The closest thing I could find to a recommendation was a 2012 video of a Marchozzi employee rebuilding a fork with a similar design where around 17:40 he uses an amber coloured grease (likely calcium grease) to lubricate the dust seals. While there was no clear shot of the product used and no specific grease type mentioned, the recommendation was to use "lightweight low-friction grease".

Following that recommendation you would be safe using most types of general-purpose grease including castor oil based greases (as they will not degrade rubber seals), silicone or teflon grease (also safe to use with rubber), lithium grease, graphite grease, or calcium grease. Greases designed for high temperature/high pressure situations (such as automotive bearing grease) will not be as effective at lubricating a fork spring under typical use so should be avoided unless that is all that is available.

The "recommended grease" ?  I have no idea.

But since the area in question isn't made with fine tolerances, I'd say any automotive grease would be okay.  The purpose of the grease will be to prevent exposed steel surfaces from rusting or binding.

Personally I'd use marine grade grease for wheel bearings.  Its a bit tackier than regular grease but resists washing out a little better.


Threatening swerving by driver - should I report it? (Canada) I'm curious to get some opinions on this from other cyclists. FYI this event took place in Ottawa, Canada.

On my work commute, there are about 3 blocks where I ride in the lane with cars because there are no bike lanes or sharrows, and I need to make a left turn in one of two left turning lanes, onto another street which also has no bike lane, and no shoulder. Details below in photo.

During that part of my commute two days ago, I stopped at a red light, in the middle of the left turn lane at the front of a line of several cars. The car behind me honked while we were still stopped, clearly wanting me to get out of his way before we'd even started moving. I stayed where I was since there was nowhere to go: another left-turning traffic lane to my left, and a straight through lane on my right that only buses can proceed through. After taking the left turn, I proceeded in the center of the lane for one block before signalling a right turn, after which I normally ride on the side of the lane because there is more space.

While I was riding the block right after the left turn, the driver who had honked at me pulled into the other lane to pass, then while passing, i.e. while right next to me, quickly swerved back about halfway into my lane, coming within about one foot of me while I was riding, then back out into his own lane. This was clearly meant as a threatening maneuver to scare me. The vehicle did not make contact with me.

I was able to memorize his license plate, make and model, and car color, and I took note of the exact time time, so I can certainly pinpoint who it was in a police report.

So I'm wondering if it's worth reporting something like this to the police, or will that just be an exercise in frustration?

If anyone has any tips or suggestions on reporting something like this, I would appreciate it. (Again, this is in Canada, so any locally relevant tips would be great)

I also live in Ottawa so I can provide some pertinent viewpoints.  Yes, you should report it, and yes, it will probably be an exercise in frustration. Don't expect the police to do anything about it. However, you should report it anyway, it might end up in a database somewhere and give them another data point about why it's important to build more cycle lanes and increase driver education on the issue of cyclists.  If they notice a trend of complaints against the same vehicle, perhaps they will be able to do something about it.

A little anecdote.  I once saw a car ram into the back of another guy's car at a stop light. The driver in question fled the scene. I was able to catch the license plate as I was walking down the sidewalk at the time of the accident.  Even though the police were able to find the car, and identify that indeed it matched the description and damage, they were unable to press charges for fleeing the scene because the owner of the car claimed he wasn't driving, and the police therefore didn't have enough evidence to actually issue a ticket or charge the suspected driver.

Without video evidence, there is probably little they can do to actually issue a ticket.

If you are uncomfortable making this turn because of the high amount of traffic and because of incidents like this. You can just head straight on Rideau across the intersection and then wait for the light to change and then go straight across Sussex.  This will avoid a lot of traffic and won't add much extra time to your commute.  You might even possibly avoid issues like this in the future.  It's not great that cyclists have to ride so defensively, but it's better to be safe than sorry.

Hopefully this situation won't turn you off cycling. I've found that most of the drivers in the city give quite a bit of room to cyclists, but there are always bad apples in the bunch.

One last point, if you want to ride the city without having to deal with traffic, check out the CN Cycle for CHEO. You got 2 weeks to get ready, and it's a great way to see the city and help a worthy cause.

Yes, you should report it: Maybe the car's owner will get a nasty phone call or letter from the police. The best case is that it was somebody's kid or husband driving, and he'll loose his keys.

The police should also give you a serious talking to about the serious accidents they have seen between cars and bikes.  Having nearly been killed on a bike, I won't go near traffic anymore.  Not getting off the road when someone is honking and presumably angry is a good way to get wiped out of the gene pool, regardless of traffic regulations.  I knew a girl from highschool who was in the bike lane on a heavy-traffic 6-lane road when someone opened a car door right in front of her.  She fell and her skull was crushed by a bus, and my immediate reaction was that she was incredibly reckless to be riding there.


I generally commute along four-lane 30 mph [50 km/h] main streets. Is this wise? crasic's view

Elsewhere, crasic writes:

  The Most Direct Route is Not Always the Best

  ... Your driving commute route is usually a horrible bicycling commute route. I purposefully avoid big roads as much as possible and take small residential streets or dedicated bike paths when available. An extra mile on a bike path can actually save you time over a shorter busy commute route — not to mention the savings to your health, safety, and the increase in your general enjoyment. If my commute reminds me of my Sunday ride, then I know I have a good route.

  You are a bicyclist. There is no reason to endanger your life on the 50mph [80 km/h] express-way when the 25mph [40 km/h] residential street can get you there just as quickly. In California, residential streets are often extremely wide (Parked car + Bike Lane + 1.5Width lanes both ways) compared to dedicated expressways — and can be orders of magnitude more safe and comfortable to ride. The pavement is often newer and less broken.

  If you are new to the area, spend a weekend or two just exploring local residential streets. Hop on over to Google Maps and find the a way to use small streets to get to where you need to go. (Often this involves riding through the residential maze and with at least 5 or 6 street changes.) Practice your route at least once and carry a printout of the route with you at least the first few times.

  [...] During busy commutes, drivers are often distracted in many different ways (putting on makeup, drinking coffee, worrying about being late, etc.) and can be unaware of bicyclists. Nothing will ruin your day more than an accident on the way to work.

John Forester's view

But, if I remember correctly, John Forester writes in Effective Cycling that four-lane main streets (with traffic lights) are better for commuting than little two-lane residential streets (with four-way stop signs at every block). The main streets are straighter and flatter. He adds that, if you take the lane, drivers will notice you and give you space. (Personally, I do generally take the lane.)

My usual practice

[Edit: I'm in Toronto, Canada.]

I'm seriously annoyed by having to brake heavily at every single four-way stop sign (especially when descending). Also, the residential street grid doesn't always pass underneath expressways or major railway lines. So I tend to end up doing most of my commuting along busy 30 mph [50 km/h] main streets, rather than quiet residential streets.

I don't usually commute during rush hour. The car drivers seem to calmly accept it when I take the lane; and I accept the drivers' right to use the road too.

My question

Is it wise for me to stick to main streets for the majority of my ride, even though there are quiet residential streets just a block away?

You need to exercise judgment based on your circumstances.

I generally agree with the advice to ride on arterial roads rather than side streets. But in my own town, there are some arterials I'll gladly ride on, and some I won't go near. There are many side streets that would be slow, with constant stopping, and a couple that are practically bike highways.

So: is it "wise" to ride on main streets? That depends on whether you're trying to get somewhere quickly or want to take it easy. On how fast and aggressive traffic is on the road. On how wide the lanes are.

If you're asking whether it's "safe," that's another question. Bike riders tend to be overwhelmingly concerned about "overtaking collisions," where the car runs over you as it passes you. These are obviously scary. They make up a low proportion of all bike v car collisions, although they do make up the plurality of all bike v car fatalities (although less than 2% of bike v car collisions result in a rider fatality). Most bike v car collisions occur at intersections. If an arterial has fewer intersections along the way, and those intersections are better controlled, it seems that the arterial should be a safer place to ride.

I second in particular the first sentence of Adam's answer ("exercise your judgement") but would like to add another thought or two.
I have ridden bikes in places as disparate as Berlin, Germany; Houston, TX; Portland, OR, and two weeks or so in Manhattan.
My experience is that in general riding on the road feels safer where motorists are used to bicyclers and have more practice overtaking them safely. In Texas one could feel that they didn't quite know how much lateral distance to keep, whether to wait or not etc. — generally spoken, how to behave when confronted with this alien traffic participant. In Portland and Berlin it's not always exactly safe but I usually feel that the motorists know what they are doing.
But there are exceptions to that rule which were caused by the traffic situation.
Portland is known as a bicycle friendly city but I felt extremely uncomfortable on the roads that connect Beaverton to the city (Barnes/Burnside and NW Cornell); they wind through mountains without any shoulder or bike path and even though they are in parts only one lane in each direction they serve as commute arteries, with non-residential traffic. I tried a few times to navigate them but felt so unsafe and uncomfortable that I decided not to ride them at all. Instead I took the bike on the tram/light rail, which is very good there.
In Houston (Bunker Hill area) the advantage was that there is often a shoulder or sidewalk or strip mall one could use. Going on large roads like Westheimer without that was uncomfortable but felt doable. It was not as prohibitive as the Portland situation because visibility was better (no hills, no curves) and there were two lanes per direction, allowing the cars to pass easier. Paradoxically I feel safer when I'm faster: The motorists behind me feel less of an urge to pass quickly, and they have more time to notice me and come up with a conscious plan of action. Being slow made the uphill sections in Portland particularly unsafe.
My rule is the following:
Be wary if there is no bike path or shoulder and you must be directly in the cars' way. Listen to your gut feeling. If it feels to uncomfortable, it is probably too dangerous. Dangerous situations are warning shots.
The actual level of danger is a mix of the general bike-awareness of the motorists and the particular street situation, the latter overriding the former: Is the visibility good? Is it a street with businesses (Westheimer) or a pure through-street (Barnes)? Is it easy for cars to pass or are they stuck behind you unless they take risks?


How do I know if it's worth restoring my bike? I found myself in need of a bike, but buying a new one is out of the question. So two possibilities remain:

buy a used one for a low price;
fix one of my old bikes.

But here comes another problem (and my question): how old is too old? I mean, apart from comparing the price, how do I know that fixing a bike is just a waste of time and money because it's simply too old?

What should I consider for changing my choice from "fix it" to "buy it"? Rust? Other things?

I volunteer at a community bike shop. We take old donated bikes and fix them up for sale, so I have a lot of experience with this exact dilemma. Here are a few reasons why I will stop working on a bike I am refurbishing:

Frame has worse than just surface rust: i.e. extensive pitting and / or holes.
Seized parts, especially if they need replacing. Sometimes a seized seatpost isn't so bad, as long as the bike is sold along with that information. However if the bottom bracket needs service and can't be removed, the frame is scrap. The same goes for quill stems that can't be removed, locking the fork into the frame.
Damaged threads. If it's not possible to rethread an interface that has been wrecked (e.g. cross threaded), scrap the frame.
Bent or cracked tubing. The odd dent is fine, but if a bike has obviously been bent in an accident I scrap the frame. Same goes for tubes with any cracks in them, even if it's fixable. Obviously any carbon frame with cracks is worthless.

I'd also add that the original quality of the bike plays into these determinations as well. I will spend a lot less time working on the seized seatpost of an old BSO.

I'll also point out that a lot of these issues can be solved with extreme effort, e.g. replacing tubes in the frame. It just isn't worth it in this context and I suspect the same guideline applies for most folks tinkering at home.

I have just restored my bike and have a few tips:

If there is rust on the frame, don't worry -- just look around in shops such as B&Q for wet and dry sandpaper which you can use to get rid of the rust.
If it is chrome, don't use the sandpaper because it will get rid of the chrome. Just use metal polish and this will get rid of the rust but not all of it.

All the other things don't worry about you would be able to get them cheap enough.


Road Bike or Mountain I have a 2014 Apollo Evade mountain bike that I have upgraded to ride on the roads for long journeys and commute. This bike now runs like a dream pretty fast for a bike that cost me £120 new plus £30 each for tyres (schwalbe city) and £50 each for lighter sports wheels. I roughly ride about 150 miles a week on average and have completed about 10k miles in 2 years. everyone I have spoken to suggest I should now upgrade to a road bike as it is more suited to my journeys but other than being lighter and quicker, what other advantages are there to me spending 5 times the amount that I have spent on my current bike? And I can cover 20 miles in 1 hour 10 mins on a MTB. And because of my good health and fitness I don't even feel tyred (ha ha) afterwards for riding something that quoted to be slow heavy and supposed to be used on mountains. What do you think is the best option stick with my MTB or go for a massive upgrade to a quality road bike? Please advise.

Salesman: Certainly you should upgrade you bike. You will go faster, further and leap tall buildings in a single bound. Woman will throw themselves at you, men will be intimidated by you masculinity.

Financial Advisor: Buying a bike worth 5 times as much to do the same job your current bike does is not a prudent financial investment. You should stick to the bike you have that is working perfectly well for you.

I cannot tell you who to listen to. What I will say is  £120 is a pretty cheap bike (BSO) and it would almost certainly be better to spend money on a better bike than upgrading it further. If you are happy with your current bike, I suggest start saving for a new one then ride the old one until buying a new bike is less about worry about what it costs and more about looking forward to riding a better bike.

This forum is like a bike calculator. My own terminology, but what I mean is that most of the regular contributors in this forum answer based on facts and calculations using their brain, not based on emotion and fashion. Whilst they are a very knowledgeable bunch, I feel like some of us are more keen to...ahem... splash the cash, splosh the dosh, blow the dough, spray some pay, or at least to buy things that are "nicer" rather than just being more functional and cost effective.

I however am severely materialistic, and I like to look downright peng when on my bike. So I would advise that if/when you can afford it, without it negatively impacting other important aspects of your life, then why not treat yourself to something a little tastier. You might be fast on your current set up, but you will be faster on a lighter, stiffer, more aero and potentially more suitably geared road bike, that's not an opinion it's the laws of physics. Maybe you aren't interested in going faster or in going the same speed for less effort, in which case you have very little to gain from getting a better bike, but c'mon? really?


Braking one-handed to signal down steep traffic-heavy slope I've just recently picked up biking and will be cycling to work when I start in a few weeks. One thing that's really bothering me on my route is a very steep hill that gets very busy during rush hour. At the bottom there's a traffic light where I have to turn right (I live in the UK, we drive on the left).

I've been doing the route off-peak to practice. Thus far it's been clear behind me each time, so I've just looked back and drifted right to position myself correctly before the right turn. However, if there's traffic behind me, I would not feel safe doing this manoeuvre without hand-signalling to the right.

Is it safe to just brake with my left hand on a steep hill? (I believe that's the rear brake on British bikes.) Can I initially brake with both hands then briefly take my right hand off to signal? I've literally never braked one-handed, so it kind of terrifies me. Sorry if these sound like dumb questions; I just don't want to get injured!

Thanks!

As an confident road rider I'd do two major things.

I'd turn my head, look backward and make eye contact with the driver(s) just behind me to show intention, and maybe signal at this point.  Or I might not signal at all.  Then
take the lane.  You will be moving fast enough to slot-in with the cars because of the downhill.  I'd avoid being sidelined on the side of the road.  I'd also do this well-before the intersection; hard to say how far but even 50-100 metres out.

If I'm needing to brake hard, I'll use both hands, and leave signalling/indicating out of it completely.  You've already shown your intent by taking the lane and moving closer to the center-line.

Since your experience is lesser, feel free to not do any of that.  You have to be comfortable with your intent and actions.  So instead you could:

Get off and walk this bit.  Brake early, loose speed from the downhill, and simply walk across the roads before the intersection.
If permitted, you could ride on the footpath, though the UK doesn't allow this unless it's a specific shared path.
Find another route to work.  There's a fair assumption that the best route for a car is also the best route for a bike, when frequently there are alternatives only available to bikes.

Also, if other cyclists traverse this intersection then watch and observe their methods.  If it makes sense then emulate them, and if not, then don't.

I suspect that a lot of people will disagree with this answer, but what I do when unable to free a hand to signal is to stick out the corresponding leg in in a very obvious and visible way.


What direction of rotation should I mount my tyre? I have a panaracer rampage tyre which I have mounted on my front wheel. This tire has knobs in the centre tread which have a ramp on one side.

The tyre does not have a direction of rotation marked and I'm wondering which way around to mount it. I heard it can be mounted one way for 'better breaking' and the other for 'less rolling resistance'. Which way is which?

I want to set it up for less rolling resistance. When looking at the bottom of the tyre, and pushing the bike forward, should the ramped or square side of the knobs be making contact with the ground first?

I've seen this related question, but it doesn't really answer my specific query:
Which way do I orient my bike tire's tread direction? and why?

I don't own these tyres but looking at the knobs I think it's obvious which direction would have more traction for climbing - with the "sharp" edge pointing backwards and thus prevening the wheel to slide back - and the other way round for better braking and less rolling resistance.

From what I've read, some people recommend using "less rolling resistance" setting for the front wheel and "better climbing traction" for the rear - seems quite natural. But the choice is yours.

Think about a farm tractor's rear tires. The narrow part of the tread always points forward for greatest traction. I think the least rolling resistance would be gained in this direction also.

Looking at the Panracer's you have, I believe the ramp should face forward.


How do I tune up the shifters/derailleurs on my mountain bike? I have a Diamondback mountain bike with Shimano shifters that I bought used last summer, and over time the shifting has gone out of whack. For example, on the front wheel I can't shift into the easiest gear, and in some gears it sounds like the chain is rubbing on one of the derailleurs when I'm riding. Also when I'm in the hardest two gears on the back wheel, the chain slips sometimes.

I've tried adjusting the screws on the derailleurs and got the rubbing noise to go away, but it returned not long afterward.

I ride my bike to work but wouldn't call myself a cyclist. How would you explain to a child, step-by-step, how to tune up the bike's shifting? How do I know if a part needs to be replaced, and are there any parts in the shifting system that I should expect to have to replace after riding the bike 1000 miles?

You said to explain it as if to a child so here it goes.
Basic Shifter/Derailleur concepts: The derailleur spring is always pulling to the smaller ring(s). Assuming your bike has Trigger shifters since you said it was a MTB, the big thumb lever will push the derailleur to the bigger ring(s). This is true for both front and rear (left and right respectively). The trigger is basically a "catch release", letting the spring pull the derailleur to the next smaller ring.
Setting the Rear Derailleur (RD):
Preferably with the bike in a stand, but can be done upside down, get the RD into the smallest ring (pull trigger until it stops clicking).
Start turning the pedal with your one hand and push the thumb lever to shift to the next bigger ring. If it shifts smoothly and quickly, push the lever again, etc.
If, after you shift, the chain doesn't bump to the next cog, find a barrel adjuster and turn it as if you were loosening it (CCW) while still turning the pedals. You are, in essence, lengthening the cable and pulling the RD toward the bigger cog (inboard).
Once you get to the biggest cog, pull the trigger so that it starts to shift toward the smaller cogs.  If it doesn't drop down, you'll have to turn the barrel adjuster as if you were tightening it (Clockwise) effectively shortening the cable and letting the spring pull it farther outboard.
Front Derailleur (FD):
The process is similar to the RD. Shift so that it's in the smallest ring (pull the trigger).  Once there, inspect the cable.  Note how much slack there is. If the cable has a lot of slack (no tension), try to find the barrel adjuster and turn it CCW (loosen/lengthen) until there's only a very slight amount of tension. If the cable it still taut, I like to shorten the cable (turn Clockwise) until there's very little tension.
From there, turn the pedals with one hand and push the thumb lever on the left shifter.  If it goes to the next ring, sweet.  If it's having difficulty, I stop pedaling, turn the barrel adjuster CCW, then shift back to the small ring (pull the trigger), then start pedaling and push the thumb lever again. Repeat until it shifts cleanly.
Adjusting the limiters:
Both RD and FD have limiter screws that limit (obviously) the boundaries of the the derailleurs.  They will most likely be Phillips head.

They keep the RD from going into the spokes or dropping the chain between the cassette and the wheel. On the FD, they keep the chain from dropping in off the small ring or out off the big ring.
FD: Shift to your hardest gears in front (biggest ring) and back (smallest ring). Many derailleurs will label the screws with "High" or "H" and "Low" or "L". High = Hardest/Outboard, Low = Easiest/Inboard. The way the gears are now, you'll be adjusting the "H" screws.  If they aren't labeled, you'll have to look and see which screw is actually hitting, or nearest to hitting, another part of the derailleur. Adjust the FD so that the outside of the FD is about 1mm from the chain or as close as you can get it without rubbing. (The latter for cheaper cranksets that develop wobbles in the chainrings).  Adjust the RD so that the cage and pulleys are parallel with the smallest cog.
Now shift so that the RD is in the Biggest Ring and the FD is in the smallest. This is your easiest gear or fully inboard.  Now using the other screw ("L"), again, adjust the FD so that there's about 1mm space between the derailleur and the chain or until there's no rubbing.  Adjust the RD so that if you pull the cable with your hand it moves no more than 1/2 the width of the chain.  Just enough so that it can shift to the big cog easily and stay there effectively.
If there are still issues, there could be other things at play. You might have to replace housing or cables.  Maybe your RD hanger is bent.  Maybe your FD is askew

Hope that helps.

If you take this bicycle to an LBS asking them to fix this, chances are they will try spraying the guts of the shifter(s) through every opening using something like WD-40. Since WD-40 gums up after it dries, I'm not sure I'd use that; maybe this video will be helpful. You can also try lubing the cables by squirting lube into the end(s) of the housing. I favor ATF for that, but you can probably use the same lube you would use for the shifters.


Is there a title that refers to the person who selects the athletes who will join the national team? Is there a title that refers to the person who selects the athletes who will integrate the national team (for instance, in the Olympic Games)? In football(soccer), there is a Selector (Sélectionneur in French) that will create the national team. What is the equivalent in bicycle racing?

The correct title in English speaking nations is Selector. The Selectors use their knowledge of the capabilities and nature of the riders to select those that represent their region or nation. Results are important but if look up any selection criteria you will quickly see behaviour standing out as one of if not the key decider on who gets to represent their country of the elite riders. Selectors work in groups and often are made up of head and team coaches and other national federation members.

Selectors also play a role in identifying talent and bring young riders into the high performance programs offered by the national federations.

There are many hoops to jump through before being selected as a representative. Firstly a rider must be eligible this involves:

being a citizen
holding a racing licence
clean drug tests
attend sanctioned events and training as required

Once eligible selection is then based on a number of factors:

results and performances at national and international events
UCI world cup points
performance in selection trials
ability to work well in a team
would the athlete win an Olympic spot and could they go on to win a medal
technique in team races
behaviour and attitude
sport science results
fit in team composition (mainly in track events)

So in short, selection is based on not only results but a wider analysis of the rider. The Selectors still have a large role in ensuring that the national team is the best group of riders rather than the group of best riders.

Unsure of what you're asking; from my limited knowledge of racing, teams, and the Olympics, I thought there were many privately sponsored teams, and if individuals want to become a part of the Olympic TeamUSA cycling team, they have to qualify based on their stats (e.g.: in cat 1 races) It doesn't seem like there would be a stand-alone position for a person to select them, other than perhaps the Olympic team coach.

Anyone who knows more about this, please correct me where needed!


Safety - Improve braking power in wet conditions I have a Dawes Giro Competition with Vuelta Stylus Corsa rims (aluminium I think although I'm not certain), Mavic Aksion 700x25c slick tyres and Tektro R540 brakes. Brake pads are standard Tektro pads with plenty of pad left. All cabling is serviced and fully functional. Braking power is excellent in dry conditions.

When the road is wet, braking power is minimal. I need to improve braking power for the winter for my own safety. I've done some research to come up with some options:

Buy wet weather brake pads (Koolstop Dura 2 or Swissstop Green).
Buy winter tyres with lots of thread to improve grip on road.
Attempt to roughen the surface of the rims with sandpaper.

Option 1 is the cheapest and reviews of these brake pads are very positive. Option 2 is expensive and may not improve braking performance. Option 3 is hit-and-miss and I don't want to damage the rims.

What is my best option to improve my braking power in wet conditions?

Additional information from OP, provided in a comment:
I can apply the brakes quite hard without skidding. I mainly use the back brake. Perhaps new brake pads are my best option.

You have commented

  I mainly use the back brake.

I therefore propose option 4: improve your braking technique before spending any money.

If you only use half of your bicycle's brakes, you can't expect to stop quickly. Further, you're using much less than half your available braking force, because the back brake is much less effective than the front one. This is because, as you brake, your weight shifts forwards, pushing your front wheel harder onto the ground and reducing your weight on the back wheel.  On a dry road, your front brake can do almost all the work of stopping you, and stop you much faster than your rear brake. On a wet road, you need to make more careful use of both brakes because of the decreased grip of your tyres but, still, you need to be using the front brake much more than you do.

Sheldon Brown, as always, has lots of advice on braking.  Many people worry that using the front brake will cause you to go over the handlebars. It is true that if you screw up really badly and front-brake really, very, a lot, much too hard, you might go over the handlebars. I have never come close to doing this. In fifteen years of commuting by bike in two of the UK's biggest cycling cities, I've never seen anybody else do it, either. It's an incredibly rare thing to happen and not something you should be afraid of.

The main difference from rear-wheel braking is that you can essentially pull the rear brake as hard as you like and the worst that can happen is that your rear wheel will skid, which you can stop by letting go of the brakes for a moment. To use the front brake, you do need to learn how hard you can pull it in different situations. As with everything about riding bikes, the way to learn is to practise on a quiet road. I categorically promise to you that, if you brake gently with the front brake, you will not go over the handlebars. You can then experiment by braking a bit harder and moving a bit faster. You'll find that you can brake pretty hard without coming even close to having something bad happen. Brace your arms against the handlebars, too, so you're not lungeing forwards faster than the bike as you stop.

A couple of other things to bear in mind when braking in the wet.

Manhole covers and painted lines in the road can be extremely slippery: avoid them where possible. This is particularly important when using the front brake because front-wheel skids are harder to recover from; it's also important while cornering.
In general, even in the dry, be wary of using the front brake while cornering since a skid is more likely when you're putting load on the tyre by cornering and braking at the same time.
If you see that you might need to brake soon, gently apply the brakes to remove some of the water from the wheel rims. Then, if you do need to brake, your brakes will be more effective.

David Richerby's correct in suggesting that you may be able to improve your braking technique by using more of the front brake, particularly if you're experiencing skidding. And Chris H is also correct in suggesting that if you're braking hard and you're wheels aren't skidding, and you're not stopping short enough you need better friction between your brake pads and the rims.

Winter tires may give a better grip on the road, but if they're not skidding, you won't be gaining anything by upgrading.


What kind of suspension do I have and how do I make it more soft? (I'm quite small) My suspension is very stiff, I would like to know why and how to make it better for my size. My bike is a 24" Muddy-Fox Impact hard tail. I went to a trail with friends and they were OK but I was not, please help!  I have tried putting oil on the outside even trying to breakdown the suspension by letting my big friend ride it but did not work.

I've googled and found this bike on Amazon.  Its also listed at a UK site.

Second site lists this at £160 so its firmly in low-spec price range.  Most likely the front fork is based on elastomer and/or a coil spring.

Some questions that discuss the internals of a fork:

What options do I have when replacing my fork's elastomers?

and this question states typical sag values which you should measure on your bike.

What maintenance does a front suspension fork need?

If you get on the bike and the suspension doesn't sag by 10-25% then you're simply too small and light for the suspension, and softening it could require removing some elastomer or replacing the springs with softer ones.

A more expensive option is to replace the fork with a better one, but this will cost significantly more than the rest of the bike.

As a pseudo-fix you could try adding weight to the front of your bike, with a handlebar bag, front drink bottle cage, or even just getting off the saddle and leaning forward more.

I tried quite a few things with my hard-tailed bike. I put on a seat post with suspension. I got a big cushy seat with springs. I got soft cushy handle-bar grips. They all helped but nothing really did as much as getting another bike with full frame suspension. How much do you like this bike? Is it heirloom? Moderate to unpleasant vibration is kind of the nature of the beast. However, if you are not sentimentally attached to this bike and you want a more comfortable ride I would recommend a full suspension bike.


Chain rings slip when crank is turned I just pulled my old bicycle out of the garage. It's about 10 years old (a 21-speed mountain bike). It was working when it was put into storage.

When I tried to ride it today, the crank wouldn't engage properly to make the chain rings rotate; or more casually, when I pedaled nothing moved but the pedals themselves.

I flipped the bike over and if the rear wheel was spinning at a fair speed then the chain rings would engage when the crank was turned and the rear wheel had power driven to it as normally expected.

Is there a freewheel or freehub at the crank / chain ring junction that I should examine?

I read through a few dozen questions but I couldn't find any that addressed this specific issue; I hope this is a new question and not just a serious misunderstanding on my part!

I'll post a video shortly, but to give further clarification...

The chain is on the gears; the chain does not slip
I can backpedal and the chains and gears spin, as normally expected
However, if I pedal forward, the gears which are located at the pedals will not spin; the pedals rotate freely. They rotate as if the thing they are supposed to be affixed to isn't attached.

Also, I'm certainly misusing terms here! By "chain rings" and "crank" I was referring to the areas of the bike as indicated in this diagram:

A quick search turned up this post, in which the OP is having the same trouble.

It sounds like your crank is swaged to the chainrings, as in this image:

"Swaged" means the "spider" (the group of radial arms that hold the chainring) is press-fitted onto the crank arm.

A better design is to manufacture the crank arm and spider as one piece, like this:

It seems that on your crank, the connection between crank arm and spider has failed. With the bike upside down and the rear wheel spinning, the load is reduced sufficiently for the crank arm to turn the spider and rings. However, it is just metal-on-metal friction that allows this to happen. As you have seen, if the back wheel is stationary, the crank arm spins independently.

You need a new drive-side crank. I'd replace the whole chainset.

Edit: It sounds like you searched and found the same pages I did, and have gotten confused by the suggestions about Shimano's "freewheeling cranks". Rest assured, your bike will almost certainly not have any weird gimmicky technology like that. Just sounds like a not-so-common failure of a poorly-manufactured crank to me. Swaged cranks are cheap and nasty (no offence intended), but you can replace them with a forged set without breaking the bank.

Less likely than the above, but there's also the possibility if you have removable cranks (where the crank arms can be pulled   off of the spindle, like the common JIS tapered spindle cranks many mt. bikes have)  that both  crank arm have come loose from the spindle.   Take a look.  If you have that type then there's a dust cap in the center of the crank set you have to remove, under that there should be a bolt that holds the crank arm to the spindle.  Check that to see if it is loose.  If it is loose, it is best to remove both crank arms and determine what's causing it to be loose.  You may determine the taper profile on the spindle is damaged, and the spindle (or entire BB set, or possibly both the BB set and the crank set ) needs to be replaced.


misaligned wheel - could this cause problems? Last summer I was on tour with my Trek 520 when my rear rim cracked.  I found a bike shop, and they rebuilt the wheel with a new rim.

Recently I noticed the wheel was off center relative to the frame by about 1cm.  I did some basic measurements with a string to confirm the frame wasn't bent, and inserting the wheel backwards confirmed it was the wheel.

I brought it to a bike shop and they attempted to redish it.  When I picked it up the guy told me the spokes had to be adjusted unusually tight, and he was only able to correct it by so much (it's still slightly off center, but hardly noticeable).  He guessed the wheel may have been built incorrectly last year (i.e., left spokes on the right side and vice-versa), although I don't see how that's possible since the spokes weren't removed from the hub when it was rebuilt.

My question in all of this is:  Was the bike shop guy talking BS and could the off center wheel or tight spokes cause problems?

The bike shop that replaced your rim replaced it either incorrectly or with the incorrect part, I suspect.  At least some of the 2007-2008 Trek 520 shipped with Bontrager Maverick rims, featuring an offset spoke bed.  If they did in fact use the same spokes, and if they replaced it with a normal rim of appropriate ERD, the wheel will end up dished incorrectly the amount of the offset.  Similarly, if they laced the rim backwards, the wheel will end up dished incorrectly double the amount of offset.  The former is more likely, especially if you didn't get your wheel rebuilt by a mechanic who routinely works on Trek/Bontrager bicycles.

An off-center wheel will cause some odd handling characteristics, almost certainly not noticeable in normal riding conditions but you'll be able to tell that your wheels are not tracking in a straight line in low-traction scenarios, such as ice or wet grated roadways.  The more extreme the offset, the more noticeable this will be.

Otherwise, moz is absolutely correct about the rationale behind dishing and the ramifications of running spokes in too high of tension.  I'd probably ride the wheel locally until failure but I would recommend getting a properly dished and tensioned wheel built (possibly just rebuilding this wheel with the correct spokes) before going on another tour of significant distance.

On a geared bicycle the rear wheel is dished to accommadate the cassette depending on the number of cogs on the cassette.  This is to set the correct chain-line.  The chain-line is very important for the adjustment and operation of your gears.  Your wheel rim should be off center to the hub when you look at it from the rear.  Hope that helps.


How to understand tyre sizes? I'm a cycling beginner and am trying to purchase spare inner tubes from amazon. The tube sizes are usually given as:

20-622 - 25-630
27x3/4 - 27x1.00
700x20c - 700x25c

How should I understand these? What unit does 25c represent?

Those are three different sizing standards

First one is 20mm inner tube diameter and 622-630mm inner wheel diameter
Second one is inner wheel diameter of 27inches and inner tube diameter of 3/4 - 1 inch
Third is rather more confusing. The 20 and 25 refer to the inner diameter of the tube in mm. The 700c is a measure of the diameter of the wheel but c is not a nit of measurement, its a standard that came about while tire standards were being written. 700c essentially means a diameter of 622mm or 27 inches.

Your best bet is too find the same tire you currently have

  http://www.sheldonbrown.com/tire-sizing.html

If you have any more doubts check out the website above


Can I fit slightly different tyre sizes My current bike tyres are 26 x 2.0 (Manufacturer fitted tyres)

Is it possible to fit 26 x 2.1 or 26 x 1.95 on these wheels or is this going to cause an issue?

Slightly smaller is fine

There's really no possible problems going just a wee bit smaller. Even going much smaller would probably be fine.

Slightly larger is probably ok

With the original 26 x 2.0 tires on the bike, check the clearances. Remember that a 2.1 tire will be both wider and "taller". Look at how much space there is around the tire at the fork crown, where the tire is close to the downtube, where the tire passes between the seat stays, where the tire passes between the chainstays, where the tire gets closest to the seat tube... As long as there's room for a wider tire, it'll be fine.

It's really common to change out tires for slightly different sized ones.

I don't have any affiliation to this company, I had to buy a 750 grams rim to lace a 1500w motor, and I found that they recommend 1.1- 2.2 wide tyre on a 19mm rim. If they advise nearly more than an inch of flexibility on their rims, the tyre industry doesn't have all different bead standards, and you will have more than .1 inches to play with for the same kinds of rim width:

INNER RIM WIDTH: 19mm

TYRE WIDTH: 28-57mm

https://www.ryde.nl/andra-30 (formerly rigida brand)

Rims for 2 inch tyres are often 12 to 20mm. compare the width with new bike rim specifications.


How many years an aluminium frame lasts in a touring bike? How long does an aluminium frame lasts in a touring bike?

[Removed extra questions to be clear.]

Background

So far I preferred aluminium vs. steel for many reasons, but if steel lasts significantly longer, for my next touring bike I will go for steel.

My Cannondale Badboy 2004 has a crack in the alu-frame. I was surprised by this, I thought my bike will last 20+ years easily. The workshop they said this is a high quality, strong frame, but after 10 years alu frames can get tired. Especially if I use my bike both in winter and summer, as the heat change wear alu faster. They say it can be welded, which will cost significantly less vs. a new frame (if it is available), but I should be prepared for other cracks to appear. The workshop contracts a welder specialized in bike frame welding and repair.

I also found a scientific research article on this topic. If someone has access to ScienceDirect (Cicero et al. (2011): Analysis of the cracking causes in an aluminium alloy bike frame), I'd be interested in the conclusions.

I'm interested in touring bikes, not road bikes, city bikes, etc.

I'm happy to update/clarify my question if needed, make a comment.

Topics I have researched:

Maintenance on an Aluminium frame
Which type of frame is better for a touring bike, steel or aluminium?
Is it possible to repair a dent on an aluminium frame?
What are the pros and cons between an aluminium and carbon frame?
Is torque relevant for steel/aluminium? Where do I find torque specs?
non-steel frames and longevity
http://forums.mtbr.com/frame-building/aluminum-welding-cracked-frame-134600.html
http://singletrackworld.com/forum/topic/repairing-a-cracked-frame

Crack in the alu frame near the rear axe (the bike is upside down):

There are a lot of question so I will settle on the one in the title.

How many years will an current aluminum frame last of a touring bike?

Depends:

Don't know what aluminum frame
Construction is a larger factor than material
Don't know the use
Use is a larger factor than material
Don't know how you are going to care for the bike
Care/maintenance is larger factor than material

Aluminum has not changed in the 10 years

All we know is your last aluminum, high quality, strong frame bike lasted about 10 years

The best guess is your next aluminum, high quality, strong frame will also last 10 years
Really that is the best guess

That is as vague as how long will a current pair of sneakers last me?
And the best guess for how long my next pair of sneakers will last is how long did my last pair last.

Aluminum fatigues and steel does not fatigue.
As stated in a comment steel does fatigue - well not always. Mild steel will not normally admit fatigue crack growth if the applied stresses are below about 10% of the strength of the material. Materials, such as aluminium alloys, do not have any such fatigue limit. If a cyclic load is applied, aluminium alloys will always fatigue.  For the same strength a steel bike is typically going to be heavier than aluminum.  But you get a bike that is much much less susceptible to fatigue.  With steel you also get a bike that will take a ding (dent) and not compromise structural strength to the extent of aluminum. Not exactly the same thing but at the molecular level they are related. Frame Materials

Found a quoted number.  Just because it was on the Internet does not make it right but here is a 5-10 year quote.
Bike Frame: Aluminum Vs. Steel

  Aluminum frames possess the shortest fatigue life of any material used
  to manufacture bicycle frames. The typical aluminum frame possesses a
  life expectancy of five to 10 years. The fatigue life of steel is much
  longer, but the material requires more maintenance. To prevent rust
  formation steel frames must be cleaned and polished regularly and
  periodically coated with rust stop on the interior of the frame.

If you are discounting steel because it will rust then you are not caring for the bike properly.  A properly maintained and stored steel bike should not rust.  And for sure it should not rust out in your life time.   You stated bikes from you fathers era lasted 40-50 years - pretty sure they were steel bikes.

If you want fatigue free and rust free then get titanium.

Data points:

Cannondale Optimo: cracked downtube in under 2 years/12,000 km
Trek 2.3: still okay after 10 years/70,000 km.
Trek 1500: cracked drive side chainstay (age/distance not stated)

Today my Optimo 63cm ( a Cannondale , pioneers of Aluminium bicycle frame... )  develop a crack around the diameter of the downtube, only 3 cm remaining holding the tube in one piece. Tired of the mis-shifting of the rear derailleur in danseuse mode, I stopped to check. And that’s when I see this huge crack... I just had to look at the right place.  It’s a little scary , cause I just went down several hills at 65 km/h (40 mph).
Really didn’t think this would happen on a less than 2-year-old frame , with less than 12,000km.
At 6'4'' (193cm) , I'm only 180 lbs (82 kg). I also have an aluminum Trek 2.3 that is 10 years old and with at least 70,000km that has no frame problems. Its end is probably near but I was much more satisfied for its durability .
I must say that I had got it for replacing a series 1500 model ( entry level trek ) which had cracked its drive side chainstay.  Yes the Trek 2.3 gives a rough ride and the Optimo is really comfortable in comparison. But I was close to finding  hospital beds very uncomfortable for long term . I guess not all aluminum frames are born equal. I just hope that Cannondale have a warranty equal to Trek, I am waiting for the result of their investigation on my frame .


Chain sometimes jumps. New parts Can't seem to get to the bottom of this. I have an 1997 Marin Eldridge Grade. I use it mostly for touring. The chain jumps or skips. It doesn't Jump down to a smaller sprocket. What the chain does seems like it could be several things.
1.It could be riding up on the sprockets
2. It could be riding up on a chainring
3. It could be a pawl skipping.
The problem is, pretty much everything is new.
New LX chainrings,New chain Probably a Whipperman Connex 808, 8 sprocket XT cassette, and a new freehub.
It doesn't skip/jump all the time and i think it is more inclined to do it at moderate load. It seems to be getting worse.
I've been a cyclist for 43 years and can sort most things out myself but this is doing my head in.

Chain is not jumping up and or down sprockets so not changing gear. It is riding up on teeth of sprockets or chain rings. I have already stated that chain is new.
Shifter and Derailleur are Shimano XT.
No stiff links in chain.

Even though the chain is new, you could have a stiff link.  I assume you cut the new chain to get the correct length.  If so I'd start there to make sure you didn't mess up the first remaining link.  Then I'd manually check each link for a stiff one.  If you find a stiff link, you can sometimes loosen it up by bending it a bit side to side.  That is at 90 degrees to plane of the pivot.

I had problems similar to yours because the indexed lever I was using to change gear was slipping under the tension exerted by the spring in the rear derailleur.

Another possibility is damaged chain rings. You can diagnose this by adjusting the derailleur initially so that it is in a middle gear. If the chain is still skipping under load, that would suggest damaged chainrings.


What are the advantages of filling tires with Nitrogen instead of air? I am completely new to riding bikes and know that are usually filled with air but nowadays some people fill them with Nitrogen instead.

I don't know why they prefer to fill their tires with nitrogen as it is more costly than filling them with air.

What are the benefits of filling tires with Nitrogen?

There are some compelling reasons for filling vehicle tires with pure nitrogen in performance situations, but for bike tires it's just snake oil. There aren't substantial enough temperature fluctuations in a bike tire to justify the pressure consistency argument.

It's also worth noting that the air you breathe and fill your tires with is more than three-quarters Nitrogen, so this isn't as special as it may sound.

Not going to delete to lose the down votes.
The stated question is advantage is nitrogen.  Not should I use nitrogen.
I cover the technical side of the characteristics of nitrogen versus air and the chemical and physical reason for the differences.

A nitrogen molecule is larger than oxygen so it does not leak as easily/rapidly.
Nitrogen is actually a little lighter than oxygen and an nitrogen atom is smaller.
In air they both occur as molecules of two atoms.
The they way the hold hands is different so N₂ is slightly bigger then O₂.
http://www.getnitrogen.org/pdf/graham.pdf

  O2 "permeates" approximately 3-4 times faster than does N2 through a
  typical rubber.

Stable and non-reactive.
Oxygen, nitrogen, are water are all relatively stable and non-reactive.
Oxygen is a stronger oxidizing agent.
Nitrogen oxidizes the rubber at a lower rate.
Better PVT characteristics.  Nitrogen does not change pressure with temperature as much as air. You don't want the pressure in your tires to change.
Storage and transportation
There are some of rent a bike racks the use nitrogen because it is easier to get a storage and transportation permit.  Oxygen alone is not combustible but it supports combustion.  Nitrogen is not combustible does not support combustion.

Why nitrogen versus an inert gas such as Argon?
Nitrogen exists as a molecule N₂ and is nearly as stable as an inert gas.  It is used because it is available.  Nitrogen is a byproduct of liquefaction and fractional distillation of air to produce oxygen. Nitrogen is not an inert gas but a nitrogen molecule N₂ is very stable. It is a relatively cheap dry stable (non reactive) gas. And does not easily liquefy (boiling point of -320 F).

Why does Nitrogen have better PVT characteristics?

In the operating range of a tire oxygen and nitrogen have the same PVT characteristics.
They are both ideal gasses.  Ideal in that they don't liquefy and have neither attractive nor repulsive forces.  They are neutral.

A bicycle does not generate enough friction to change the temperature much.  Bicycle will be pretty close to ambient temperature.  If you start a ride in the AM you may get a 10 Celsius swing by 2 PM.

Relative to the ideal gas law, PV = NRT, oxygen and nitrogen have the same behavior.  T is absolute in that equation.  0 Celsius is 272 Kelvin (absolute).  10 to 20 Celsius is a difference of 4% in pressure.  So if the tire started at 100 PSI the pressure when to 104 PSI.

Water is the PVT problem.  Water is not an ideal gas. In the operating range of a tire H₂0 can exist as a gas and a liquid.  From the liquid state to gas state the volume change is over 100 (this is how you can inflate a tire with a little CO₂ cartridge).

In the range of 10 Celsius versus 20 Celsius the vapor pressure of H₂0 nearly doubles at atmospheric pressure.
Vapour pressure of water

Over that same 10 Celsius swing what is the pressure change of water.  The vapor pressure of water doubles.  Where the ideal gas (N₂) changes 4% water changes 100%.  In that same range the water pressure goes up 1 PSI.  So the total PSI is 105.  At only 1% composition water contribute 25% of the pressure change.  The statement from Moz that Nitrogen changes pressure with temperature slightly less than water does is not correct.  The difference is 40X but at only 1% that 40X is still not much of a total contribution.

So a 1% pressure difference in 10 centigrade.  Racers will go after grams. 1% may matter to them.  It is not clear if racers users nitrogen (in tires).  I see sellers stating it is used by races but I don't see and races saying they use nitrogen.

Nitrogen is used in altitude tents to reduce the O₂ content.  This stimulates the production of red blood cells.  So racers may use tires as an excuse for nitrogen tanks.

From 0 to 100 Celsius the vapor pressure of H₂0 goes from 611 to 101417 Pa.  In that operating range H₂0 is over 100 times more sensitive to temperature than nitrogen or oxygen relative to pressure.  So for a race car the change is noticeable.

Why CO₂ in those portable canisters and not nitrogen?
CO₂ compresses to liquid state at a lower temperature then nitrogen.  The boiling point of CO₂ is -78 Celsius. Can use CO₂ to inflate a tire and not risk it going back to a liquid state in the operating range of a tire.


Having one wheel set with 6 bolts rotors and one with center locks? I'd like to purchase a second wheel set for my bike: to have one wheel set for road, and one for cross/light MTB, and swap them easily depending on the kind of ride I plan. My bike uses 6 bolts disk brakes, but my local shop only has additional wheels with the right specs with center locks supports for the brake rotors.
Given I have to purchase additional discs anyway, is there any counter indication to have one wheel set with 6 bolts rotors, and the other wheel set with center locks rotors? Or better to order the 6 bolts version of the wheel set?
Thanks!

This is perfectly fine. I have a similar situation with my gravel/rain bike. I'm lucky enough that the rotors on the two completely different hub brands match up well enough to not require shims or adjustment. You may want to purchase some shims in case the the rotors on the two wheelsets need to be aligned.

My bike uses 6 bolts disk brakes, but my local shop only has additional wheels with the right specs with center locks supports for the brake rotors.

I hate it when people assume today that wheels are some component that is sold as-is.
In reality, a wheel consists of a hub, spokes, nipples and rim. You are free to select each and every one of those components.

Given I have to purchase additional discs anyway, is there any counter indication to have one wheel set with 6 bolts rotors, and the other wheel set with center locks rotors? Or better to order the 6 bolts version of the wheel set?

If you have exactly the same hub models on both wheelsets, you can be sure that the discs are always at the same position, thus avoiding the need to re-center brake calipers when changing wheels.
A center lock hub is never the exact same model as a 6 bolt hub.


10 speed cassette/derailleur, but only getting 8 clicks? I've got a 2013 Giant Escape 0 Hybrid with a stock 10speed Shimano Deore rear derailleur.  My wife was riding the bike the other day, and somehow managed to shift in such a way that it popped the chain off the rear cassette and jammed in between the sprockets and the spoke protector.  Luckily no damage was done.

After putting the chain back on, I put the bike up on a stand to check/tweak the derailleur alignment.  The small sprocket and the large sprocket are properly aligned.  I can shift up and down with almost no problems; I seem to skip the third gear.

If I take the rear wheel off and click the derailleur, I only count 8 clicks; not 9.

I'm not sure what that means.  Nor am I sure how my derailleur can be properly aligned on the smallest and largest cogs, hit all the shifts except for one, and yet miss an index.

Is this an alignment issue?  Is there a problem with my shifter?  Is my derailleur whacked out of position?  How/why could I be "missing" an index?

If you are skipping gears, I suggest the cable tension need to be reset. Shift to the smallest cog, undo the bolt fastening the derailleur cable and then refasten, ensuring there is just enough tension to hold the cable tight. You should then be able to accurately shift up one gear at a time and go through all 9 clicks. It may take a few attempt to get right, and you should test it with different front gears selected. Also check for worn cable or housings.

Looks like you need to set the limit adjuster also, there are two small Philips head screws that do this. They prevent the derailleur shifting past the largest and smallest sprockets.

Rear mech is bent a little . If its shifting and on 2 of the gears shifting 2