Can a 12x142 rear hub and 15mm front hub be converted to 9mm quick release with an adapter? I need to replace a pair of 26er mtb wheels and want to see if my qr fork and frame can be adapted for through axle hubs.

YES.
You will need a adaptors called "end caps" that fit the ends of the axle (front&rear) and make it compatible with the use of QR. Depending on the brand of the hubs, the "end caps" can be found on the market - otherwise will need to make it at a turnery (it's a simple work).
But there are exceptions! Some front hubs of type "Boost" are 15mm but slightly wider (110mm vs. 100mm) than traditional QR and 15mm hubs. If the wheels you buy come with this hub, it will not works even using "end caps".
Before buying future wheels, make sure there are available in the market "end caps" for them.

Yes, as the above answer has explained a some 15mm TA front hubs can be converted to use a 9mm QR.

But...

No, a rear 142x12 TA hub cannot be coverted to fit in a 135x10 frame as there is a 7mm width difference.

Also you ask if your frame or fork can be converted and the answer to that is also no. The open ended dropouts do not have a simple (and safe) solution for through axle conversion.


Does spin class prepare you for a long bike ride? I need to train for an upcoming bike ride and i wanted to see if attending a spin class 1-2 times a week (45 min course) would be appropriate way to prepare for a long bike ride (50 - 75 miles)

Regular aerobic exercise is definitely of value for preparing for a big ride. Spin is a good preparation in conjunction with some outdoor rides, but it is not a substitute for riding your bike on the road.

The feel of the bike, the balance, the momentum, and the environmental and traffic factors will have an effect on your fitness as well, some of which may be purely mental.

If time is limited, try spin 2-3 days a week, and build up your endurance, but also do at least one longer outdoor ride each week. If you're riding 50 miles, you need to plan to be on the bike for 3-5 hours when you do the actual ride.

Build up to where you can handle 3 hours on the bike easily, and you'll do fine.

I SPIN 8-12 hours a week in winter- )Pacific Northwet). I make sure I do one or two 2 hour sessions a week. It has been very effective for years. One key is to have imperial information:
watts and heart rate to make sure you are getting benefit. Some call for watts = your weight is good target. I add the weight of my bike to that as well. I also did a test for threshold watts that provides me with targets during training. I do not have it on my bike just trainer and spin bike.


Do you need brakes on a trainer / on rollers? I'm building a bike from scratch and old parts for home-trainer and roller use only. Do I need brakes or can I cheap out?

No. For fixed trainer, it should be obvious.

For rollers, rolling resistance is higher on rollers than on flat surface. Wheels don't also have much momentum, so you can slow down by freewheeling for a few seconds. The only use for brakes is preparing to dropping off the rollers: rotating tires leave a nasty skid mark on the floor but brakes stop the wheel immediately.

If your bike is to be used on rollers only it would be wise to have some brakes but it is not an absolute necessity.


Website with bicycle only paths in Europe? Does anyone know of a website that has a map of bicycle paths in Europe that are bike/walkers only, i.e. no cars?

OpenStreetMap (a collaborative project to create a free editable map of the world) has a very up to date and accurate cycle route layer available. I have used it before in Europe to plan large trips.  There are also lots of online add-on services that allow you to use the cycling OpenStreetMap to plan cycling routes and run them either on smart phones or on GPS cycling computers. Garmin has even used the service to create the specialized maps on their Edge GPS cycling computers.

Some example services include:

BikeRouteToaster
Garmin Connect
... more to come (or add them in the comments)

As a side note, other proprietary services such as Google maps also have good (and constantly improving) cycling maps.  I however personally find OpenStreetMap is a little more up-to-date and accurate, likely due to the fact anyone can submit a fixes and new pathways.

https://www.aluxurytravelblog.com/2013/10/30/5-of-the-most-scenic-car-free-bike-paths-in-europe/ and https://www.afar.com/slideshows/10-of-europe-s-greatest-cycling-routes?slide=1 are good sites to check out


My crank slips I think I've got a 2015 premium bmx. When I start to pedal, the left crank kinda slips, if that doesn't make sense, let me siimplify it. When I pedal, it's like it doesn't grab the chain or something, like it pedals and moves the chain but the wheel doesn't spin, only at first tho then it rides fine. But only when I try to pedal from the left side. I also have a freecoaster, maybe that's why but I don't know

My son and I have had direct experience with this (he is helping me write this).  I realize this thread is very old, but I put this here in case others are finding it.
First, check the chain.  If it is worn too much (they elongate over time) it won't grab the teeth.
Second, Check the chainring,  Are the teeth sharp?  If so, you need to replace it?
Third, check the teeth on the rear cog.  Again, if the are sharp, you need to replace it.

Your freewheel is failing - the pawls are not grabbing immediately which allows the chain to move without the rear wheel being powered.

This will not resolve itself over time, it will get worse.

Your two solutions are

Temporary) try washing the freewheel with solvent to get the gunk out.  Then let it dry and relube with light machine oil.

Longterm) Replace the freewheel mechanism with a new one.  You will probably need a new chain at this time too.


Do you automatically have to replace your chainrings once your chain reaches 1 % chain wear? My chain was badly worn. 1.0+ % wear. There is no visible shark toothing or extreme spacing on chainrings. Is there a chance I can get away with not replacing the chainrings, or does the amount of chain wear automatically necessitate that I replace them?

I think that one rule of thumb I saw asserted that if you replaced promptly, you could get 2-3 cassettes per chain, and 2-3 sets of chainrings per cassette. I'm not able to provide a concrete source for this right now. However, the fact is that chainrings do wear more slowly than cassettes because they have more teeth.
I think very likely that your cassette needs replacement, and I would do that preemptively. I would not replace your chainrings right now, unless they have had several prior chains that also got to a high level of wear. For smaller chainrings, I would probably lean slightly more towards preemptive replacement.

Take round file and do each tooth it's a dirty fix but works, the file must be same size as the tooth maybe slightly smaller just don't make the teeth larger as this will stretch the chain, the idea is to make them deeper.


Is it possible to ride 18km everyday for a beginner? I decided to ride to my university which is 9km away from my home and it is placed on a foothill. I guess the route is 5degrees uphill steep.

I have ridden short routes before but not as long as 18 km.. I'm a beginner in riding, but physically I'm partly OK.

EDIT:
This is the path's elevation profile from google earth:
The average slope is 4.6% and max slope is 13.1% and altitude is 1224 ft.

18km a day is not far, as long as you have an OK fitness level to start with and no health issues, it is certainly achievable, but...

You will not get any rest days. I was once told, you do not get fit exercising, you get fit recovering. If you ride 5 days a week, there's no recovery time. This could lead to problems since each day's effort is stressing your body. For the beginning I would strongly recommend not more than 3 days (with a day between) until you are sure you can comfortably do five days every week.

What I would suggest you to do is first thing in the morning measure your resting pulse rate. Do this for 3 or 4 mornings to establish a baseline. Start riding, taking it easy to begin with (for the first couple of weeks). Note how you feel and your resting pulse rate - if you feel bad and your pulse is higher than it should be, have a rest day or two. (Note - normally your resting pulse rate will fall as you get fitter, so your baseline will change.)

The trick is to have an alternative to riding available so you don't need to ride if you need a rest, but not so available that you use it all the time.

It's not that far. Just go at your own pace.
Make the bike ride fun, with a good podcast or music.
I listen with one headphone out so I can hear traffic.
You shouldn't need a break from muscle soreness.
But the days where you're sick or the weather is bad, you will need an alternative. You shouldn't ride in really windy rain.

I will buy a folding bike, and take the train (with bike) in morning, then ride home 15km later. So if public transportation is available, consider folding bikes. Also, don't be cheap on your bike purchase. If you get a cheap one, you will pay in the end with your stress.


Coping with mud in the face I am not talking about swimming in mud. Just a damp trail or even wet pavement - and some modest speed - and the front tire function switches from steering the bike to throwing mud precisely directed at the rider's face.

Without protective gear, the mud and gravel projectiles hit the eyes at unpredictable moments and the chance of loss of steering is significant.

With clear sunglasses, the lens become stained in a couple of minutes and impair vision. I am reluctant to brush them with my glove as I reckon this would:

be not very effective, only transforming the mud droplets into a solid film of mud and sand
scratch the lens badly after several tens of scrapes.

How do downhill riders cope with this? Does the full-face helmet protect the mask in some way? Do they apply anti-water coating on the mask? Do they install some hardy front fender? Or do they just live with it?

In the 2011 Megavelanche, the guy has the camera behind his mask. It got only several drops of dirty water during the entire race, regardless of him riding through snow, mud, water, dirt, gravel. How is this possible, and why do my glasses look like shit when I am touring over asphalt and it rained yesterday?

How do downhill riders cope with this?

With a front fender or with a mud guard such as this.
With goggles which use disposable tear off lenses or the ones with a reel of fresh len material which is pulled via a string or via bluetooth or something.

  Does the full-face helmet protect the mask in some way?

Probably not.

  Do they apply anti-water coating on the mask?

No

  Do they install some hardy front fender?

In really muddy conditions it's almost mandatory.

  Or do they just live with it?

Nobody likes mud in their eyes or mouth.

I use a Stealth Shield carbon fiber mudguard from Cycle Armour (order at www.cycle-armour.com). It seems to remove about 85% of the dirt from my eyes (more on straights and less on twisty parts). It weighs nothing, looks good, and is very aerodynamic. It actually automatically adjusts if thick mud is encountered.


What road hub makes the least amount of noise What brand rear hub and cassette has the lowest noise level for a road bike ?

In my experience, the most silent combination has been Shimano freehub and cheap cassette with pinned together cogs. The one I have is XT, but road hubs below Dura-Ace have similar mechanism. A cassette with loose cogs can vibrate more freely and is louder.

Other brands that I have been riding myself or have had the joy of listening on group rides include Campagnolo/Fulcrum, Chris King, Mavic, DT Swiss and so on. All of these have their own distinctive rackets.

As described in comment, completely silent roller clutch hubs have been produced. They have other, more serious problems.

It depends on your cassette as well as your freehub body.

If your hub uses a ratchet and pawl system, then, theoretically, the "quieter" freehub will be the one with less pawls - but there are many other factors that would make that not the case.

Also, higher quality hubs are associated with more pawls and more noise (think Chris King buzz).  But, this changes as the freehub breaks in, it gets quieter over time.

A lot depends on the cassette paired to the freehub, it's material, and construction.  The cassette amplifies the sound, so, for instance, a hollow dome cassette is going to be louder than the same hub paired with a heavier, more solid cassette.

I'd say if you're looking for something relatively quiet, look to buy a higher quality hub, with more pawls, thats used and broken in, and pair it with a cheaper, heavier cassette (I'd go high quality on the cassette for a stiffer gear cluster but there will probably be more noise).  Not sure what your price range is but there are many options across the board.  Some brands I'd look at would be:

White Industries
Chris King
DT Swiss


Does it matter where you buy the bike? You can buy the same bike at different stores (see for example the Schwinn Discover, here, here, and here). Does the place where you buy the bike from matter in terms of what parts they put on it? Or is the only difference in the assembly?

It matters in many ways where you buy the bike from. If you're buying online, then the parts will most likely be the same, although you should be careful to read the specs.  Some online (brick and mortar as well) shops will have overstock bikes from previous years and the parts will be different from the current model year.

If you buy from a local bike store, then it starts to make more of a difference where you shop. Many shops will offer free tune-ups for a year or two, and some others will offer free tune-ups for life.  What's included in a "tune-up" can vary from store to store.  Some shops will include a free fitting of the bike to make sure it's properly set up.

Every actual bike shop, and dedicated sporting goods store that I have been to has, at the minimum, given the bike a the bike a safety check before they actually hand it over to you. I even got this once for a coaster bike (the kind with no pedals/drivetrain) when I bought one for my 3 year old.

This is to ensure that the bike is in safe operating condition and to ensure that things are working well.  Problems can arise between the initial assembly and when you purchase the bike and they want to ensure that you will be safe and have a good experience.  Stuff like this often isn't done at places like Walmart or Amazon. Often they will assemble the bike and not even give it a test ride to ensure things are actually working properly.

way back in the 70's I bought my first bike at a 'bike store' and thought having to lean to a side was the norm.  Years later, having much more experience, I found out the frame was misaligned.  What got me is this store which was supposed to be catering to bike enthusiasts would put out something like that and sell it at a premium price.

If a frame is misaligned there isn't much you can do.  Any experienced shop owner would reject it instead of trying to sell it to an unsuspecting customer.

I modified the bike by gearing it up to 15 speed from 10 speed. but not in the way most people do.  whereas most gear down to make it easier on hills, I went the other way and got a bigger sprocket on the front.  I also moved the shift levers to the handle bars (shimano).  I know people say they are slow but I like the comfort.  Switched to cloth wrapped handlebars as well.  stripped all unnecessary other stuff off the bike, but it was a circa '76 bike and weighed in around 30 lbs.

I did ride the bike on several century races for fun and experience but always had to sit to the side in the saddle.


best ride to burn tummy fat what type of ride should I choose? I own kross k10 bike. Currently I am doing 7.7 km lap with combination of slow-fast-slow (40%-20%-40%) of total path.

Am I doing it correct?

You can't really burn "tummy fat."  Your body has an order that it will store fat in and it will lose fat in the reverse order.  You can lose bodyfat, but it goes away in the reverse order that you put it on.  You can make it appear that you've proportionally lost more weight in your tummy by building up the muscles there.

The basics are that in short and intensive you will burn more fat in shorter time. However you can hold easy and steady pace for longer time burning more calories as you go. You can choose either approach.

Don't look too much at minutes&speed&terrain. Heart rate monitor is more important.


Red light facing forwards? I was criticized for having a blinking red light facing forwards on my handlebars (in addition to a White headlight). What is wrong with this? It was nighttime in Manhattan. Isn't more always better when it comes to being seen?

THANK YOU FOR THE ANSWERS, my mistake has been corrected. Best wishes to you all.

No. You should always ride with a white light facing forward and a red light facing backwards. If you want additional illumination, you can add multiple white/red lights in the appropriate direction. Amber/yellow lights can be used facing any direction for additional visibility.

The first reason is that it's the law:

  (a) Every bicycle when in use during the period from one-half hour after sunset to one-half hour before sunrise shall be equipped with a lamp on the front which shall emit a white light visible during hours of darkness from a distance of at least five hundred feet to the front and with a red or amber light visible to the rear for three hundred feet. Effective July first, nineteen hundred seventy-six, at least one of these lights shall be visible for two hundred feet from each side.

More importantly for your safety though, the color of a light conveys a certain meaning. Drivers, pedestrians, and other cyclists associate the color red with a taillight and the color white with a headlight. If you put the wrong color facing the wrong direction, people may think you are traveling the opposite direction. Imagine a car is pulling out of a driveway and sees a red bike light flashing to their left. They may assume that means a bike is moving away from them on the left. If they then pull out of the driveway and you're really moving towards them, you could get hit.

It's more because when a red light is shone, it implies to face an observer from either idle stance or from the same direction. But, if they were white, it'd imply onward, additive-to-impact velocities and state of impulse direction.


Inexperienced rider - double chainring? I'm a fairly inexperienced (and out of shape) rider who has recently moved to Seattle, a very hilly area. I used to ride a Fuji Traverse (hybrid) in my original hometown, Tallahassee (which also has some hills). The Traverse had a triple chainring, and I found myself using the granny gear a lot on hills. In fact, I'd even sometimes switch down to the big climbing ring in the rear on steeper hills. (Edit: Checking my Strava, it looks like these grades were 7-8% on average.)

I'm buying a new bike now that I'm here in Seattle, as I didn't bring the original with me. I'm looking at entry-level road bikes, but these bikes tend to have double-chainrings. I am aware that triple chainrings usually have gear ratios allowing for an easier time with hills.

Should an inexperienced rider facing hilly terrain buy a bike with a double chainring, or should they always stick with a triple?

I went to college in Seattle and love the town. Very bicycle friendly town.  It does have ups and downs but the bike paths are pretty flat. If you you live on one of the hills then yes you may have a short steep section.

As cassettes have gotten bigger (9+) you can get a pretty big range so triple is less common.  Get a compact up front so you can use a 34T for the smaller. The 8 speed cassette bike you are looking at is 32T so you are pretty close to 1:1 which is a strong climber.  With a 9 speed you can get a 34 with the same spacing for a 1:1.  But a 9 speed will be a jump in price.

As an inexperienced rider with stop and go type traffic of a big city a hybrid or city type bike might be a better choice over a pure road bike.

I would concur, triple chain rings are really not useful.  My rule is that riding is effort.  The watts you can sustain to "go along" are about the same, no matter what conditions.  The difference is the ease in which you turn the pedals.  However, this nonetheless creates a trade off.  To keep the rpms up also takes effort.  The easier you make it to spin, then the higher the rpms you need to keep moving.  So there is a trade, but the bottom line is effort.  The difference is in the variety of hills you can go up.  You can go up a bigger variety of hills with a bigger variety of gears.  But, as I said above, you still need effort.  So a steep hill may be beyond your effort, so even with a more favorable chain ring, you may still not be able to take it.  If you are avoiding those huge hills in favor of routes with more reasonable and realistic hills, then you have reduced the variety and likewise the need for a bigger range of gears.

To really enjoy riding longer distances go DI2, because it will make shifting more enjoyable and you will use more of the gears you have rather than avoiding shifting as is a common mistake for occasional riders.


How do I open a master link in a chain? How can I undo a chain that is closed with a master link?

Inspired by comment from https://bicycles.stackexchange.com/a/39284/19705

I use a tool made out of a steel wire clotheshanger to squeeze the two pins together and open the link.

Also, that one hanger turned into three tools: the link opener, a tool to hold the ends of an open chain together, and one to hang the cleaned-and-drying chain from the tree over the driveway.

How can I undo a chain that is closed with a master link?

The difficulty of opening a master link in a dirty chain is alone a reason not to use those master links. You can open a master link in a clean chain with your hands -- the only drawback is that your hands get dirty with chain lube but then that's obvious if you are disconnecting a chain. But why would anyone want to open a master link in a clean chain is a mystery to me. Chains are only clean if not used, and this in practice means you're disconnecting a chain you just installed, meaning you would have saved time by not installing the chain in the first place!
However, in a dirty chain opening the master link is no longer as easy. The sand held in place by the chain lubricant prevents any attempts to open it with reasonable force. To open it, you need pliers -- a tool far larger and heavierweight than the tool to push a chain pin out.
Because carrying pliers is not reasonable in one's emergency toolkit all the time, and because you need a chain tool anyway as a chain can break at a pin and with the master link solution you have to have always the ability to push out a pin completely to replace a broken link with a spare master link you carry with you, my recommendation is to forget those master links and use chains connected by reinforced connecting pins (Shimano).


New chain is pre-lubricated, should I clean it before use? My new chain is totally coated in lube. I would never ride a bike with a chain like this normally. All that goop is just going to collect flotsam from the road and wear out the chain.

Should I clean this coating off the new chain too?

The coating is generally a form of wax, which is an excellent chain lube, and less apt to attract dirt than most chain oils.  All you really should do is wipe off (with a dry cloth) any excess.

If the wax seems excessively heavy you can add a little solvent to the cloth, to just wipe off the outer coating.  You want to leave the lube on the inside of the chain, where it's really needed.

Best advice for anyone running a 1x11 setup and using a SRAM or KMC chain right out of the box, is to get all of this thick wax off first, then reapply your own lube!  One ride and your chain acts like a magnet to dirt and dust.  Not only that but it also causes the chain to grab the cogs and the front chainring causing a knocking/clicking sound which will make you think that your bottom bracket is about to fall out.  This will save you so much time and frustration. I'm surprised that these companies haven't figured this out yet and stopped using this CRAP! Hope this helps you.  Cheers!


Help identify BMX please - possibly 80s or early 90s I recently picked up this old BMX bike for AU$5 at a garage sale. I was originally only interested in the Skyway Turbo Disc chain wheel, but decided I would strip the whole thing and give it a new lease on life. If anyone can ID the make, and even better the model, I would be very grateful. The frame has a distinctive gusset at the intersection of the top tube, down tube and head tube.

PMX Clubmaster from bmxmuseum.com

bmxmuseum has PMX bikes from 1982 to 1984 named "Clubmaster" or just "Club"

The bike pictured does not have original parts.

According to this link the PMX Club is a steel frame bike from Germany

I think I had this Bike. It was a cheapy kit in a box called a Sapphire. Firend of mine found it - best bike on a budget.


Does Selle Italia Flite Genuine Gel have rigid shell? I am asking for version without a cutout. The question is about the shell (not the padding) -- when you press with your hand in the middle of the saddle (from top to down, like you would sit on it) -- does the shell flex?

Please note, I am not asking about opinion/recommendation, just data about stiffness of this particular saddle.

There is approximately 5mm of gel padding, over a reasonably flexible base on the Flite Gel. I would not consider it an especially rigid saddle.

Yes I had a Selle Italia Flite Genuine Gel this summer and it was very stiff and rigid...it was wonderful.


Is my local bike shop asking to much money to change a rear cog? I normally have much love for my LBS, but I've moved recently and am a little unsure about this new one due to the fees he is asking.

I have a flip flop hub with a fixed gear (18 tooth) cog on one side, and a freewheel single speed cog on the other side. I need the fixed gear cog replaced. As I understand all you need to take this off is a special tool every bike shop would have. I assume the whole replacement process would take all of 5 minutes - quicker (like 2 min) for an experienced mechanic -- is this true?

The shop wants $50 labour to do this. Seems a little steep, I think! Am I right to think that this rate is unreasonably high?

Ah the internet.

Answered my own Q:

It takes about a minute. Yay!

Watch at 2:13: Replace Fixed Cog (broken link)

Instead, try

How To Change A Track Bike Or Fixie Sprocket  (splined).
FIXIE COG INSTALL #3 (threaded)

For DIY: need a chainwhip and a lockring wrench / lockring spanner

...or a multi-tool with chainwhip & lockring wrench!

Done.

I've got a flip flop hub myself and haven't got any of those specialised tools, all you need is a screwdriver and a hammer.  The lock ring is nothing more than nut that holds on the gear.

If you're replacing the cog, you might find that your chain might be worn too and might skip around on the new cog.


Can a 10-speed chain be used with a 9-speed cassette? I have an extra 10-speed chain I would like to use with a 9-speed cassette on my mountain bike. Will this combination work ok?

The 10 speed chain is narrower and will work. Not ideal and the shifting might not be as crisp.

Since you have an extra chain you can use it, but if purchasing new I would get a 9 speed chain.

I fact, a 10 or 11 speed chain will work BETTER than a 9 speed chain on a 9 speed casstte.
The reason is the chain and not the casstte is the limiting factor in a drivetrain-usually
The chain is under such incredible stresses.  Chains have evolved to be chamfered, to engage with the front(this derailleur is actually under more stress than the rear derailluer.  It simply pushes against the chain to move it between chainrings.  The rear derailleur is a more advanced mechanism).
So, if you can alaways get the narrowest, strongest chain that will fit on your bike.  And that is usually a higher speed chain than what came with one's cassette.
I would also change the casstte too when changing to a new chain.  It's just good bike mechanic technique.


Why are almost all bicycle tyres cross-ply/bias ply and not radial construction? Most times when I see a failed bicycle tyre (one where the threads are showing through) they look something like this, with diagonal threads clearly visible

Here's a random manufacturer's cutaway showing diagonal casing threads

Here's a line diagram showing the difference:

So I'd reason that most/all bicycle tires are Cross Ply in build, and not Radial.

My google-fu does return these points:

Radial tyres are cheaper to make than the equivalent cross ply
Radial tyres are lighter and have better fuel economy than a cross ply
Radial tyres track better, where cross ply tyres have been known to "tramline" vehicles.
Cross ply tyres have a more rigid sidewall, radial tyres have a more supple sidewall.
Suspension needs to be altered in a car to accommodate the differences between ride handling in the two styles.

Usage

Automobiles tyres are almost exclusively radial.
4WD tyres are predominantly radial, but cross ply have much better sidewall strength and resist damage better.
Motorcycle tyres may be either, where radials are preferred for speed and cross ply are preferred for load carrying (touring or cruising)
Truck (ie load carrying vehicles) might use either, with cross ply for load carrying and radial for long distance.

Even wikipedia is ambiguous, saying

  Radial tires have occasionally found application on bicycles, used on the 1980s Miyata touring bicycle; models 1000 and 610,[19] and more recently in 2009 on the Maxxis Radiale.[20] Panaracer radial tires were also standard on the Jamis Gentry model bicycle in 1985.

I would have expected that radial construction with "supple side walls" to help a lot in reducing rolling resistance, but its uncommon.

Why are Radial tyre constructions uncommon in bicycle tyres?

Radial bicycle tires are very rare. The reason is that the lateral stiffness is much lower than for cross-ply tires. Imagine that you press the sidewall of a tire by your thumb. With a cross-ply casing the cords on which you apply pressure are anchored to the bead wires over a distance of about twice the tire width and the whole section shares resistance to deformation. In case of a radial tire the cords run in the same direction as the force, hence offer very limited resistance. Radial tires are prone to squirming and unstable cornering.

Yet a few manufactures still offer radial tires. I know of the Vittoria Diamante Pro Radiale 700x22 for road bikes and the CST Sensamo Speed 35-622 for touring bikes.
The riding experience with the Vittoria tires, published on https://cycletechreview.com/2012/reviews/vittoria-diamante-pro-radiale-tyre-review/  , suggest that they might please persevering afficionado's.
It is probably not accidental that the width is limited to 22 mm. The bigger the diameter, the softer the structure get and, probably, the higher the inflation pressure required for stable load carrying (limited load carrying might be the explanation why airplanes and heavy trucks don't use radial tires but cross-ply tires).

In his study of tire properties, Andrew Dressel included a Maxxis prototype 22-622 tire. He reports (page 113)  'The Maxxis prototype, which is described as “radial” and does appear to have cords aligned at about 22.5º, instead of the 45º usually associated with bias-ply, does not have stiffnesses noticeably different from other tires of similar size.' Here the small width combined with the in-between design would explain the results. See  https://dc.uwm.edu/etd/386/

Bicycle rims are not designed for radials.  https://www.sema.org/files/attachments/WTC-2011-05-Bias-vs-Radial-Tire-Wheel-Fitment.pdf


Tire clearance on 2019 Trek Crockett Has anyone tested max tire width on a Trek Crockett (2019 frameset)? Wondering specifically if I can fit 45mm tires on 19mm inner width rims.

Suggests that 19mm is the upper limit for 45mm tyres but should still work.

If you have any choice, 23mm wide rims would be better.  Depends if in the future you want larger than 45mm wide tyres, or smaller.


Single-speed vs Multi-speed bike purchase I am looking at buying my first bike as an adult.  I grew up in a neighborhood that was very hilly, so am used to getting bikes with gears to be able to do hills more easily.  I now live somewhere comparatively flat (long shallow hills; E.g. 0.5 mile at a few degree incline, <5 degrees), but am very out of shape.

Question:  What are the real things I need to consider to decide

1) Whether I need a multi-speed bike at all

2) How many speed bike I need?

For completeness & context
I am about 6' and 160 lbs but not in shape at all.  I currently walk or bus pretty much everywhere.  I'm looking to use the bike mostly for getting to/from work, not necessarily to get in shape.   My ride to work can be 0.5-3 miles, depending on if I decide to ride to transit or bike the whole way.

Single speed bikes tend to be very low end bikes--aside from fixies, but those are a different animal altogether.  As such, you almost certainly will want a multispeed bike.  Don't get too focused on having a specific number of gears.  Instead, focus on a bike that meets your needs.  For commuting, you'll mainly be looking at commuter bikes and road bikes, and you'll likely be looking at a derailer bike with at least 16 gears.

Visit some local bike shops with absolutely ZERO intention of buying something that day.  Depending upon where you live, the selection of shops may range from great to sparse.  Get a feel for the place and how they treat you.  The customer experience will range from great to awful.

I strongly urge that you stay away from big box stores and only shop at local bike shops.  You will have a far better selection of bikes at a local bike shop, and service is non-existent at big box stores.

What's available at bike shops in your area may be completely different from what's available in my area.  As such, it's impossible for anyone on the Internet to make specific recommendations.  It's best if you look at the inventory of bikes in shops in your area.  Something that you have to custom order or drive 100 miles to pick up adds a lot of unnecessary expense and hassle.

Out of shape kind of favors single speed.  You don't have the output for bigger gears.  You could just just set the SS up with a lower fixed gear. Like a 32 tooth front and 20 tooth rear. I commute on a SS in a flat city with no regrets. In that one gear a SS is efficient.  A SS is easier and cheaper to maintain.

A SS is cheaper.  If you only want to spend $400 then SS.  If you are going to spend $800+ then you are going to find a decent quality multi speed.

Once you graduate into longer road rides then you will want a multi speed.

But you can get multi speed and just use a couple gears.  Just don't get a cheap (BSO) multi speed.

I also have both a SS and MS mountain bikes. For me SS is just plain fun. It is you and the pedal.

I have several bikes and this SS I got used for $400 is still one of my favorites.  If I have a non biking friend that wants to go for a ride I put them on this bike (with a bigger seat).


How do I know if there is water in my fork I have a SunTour XCR fork. Not wanting to ruin it I am worried that a significant amount of water has penetrated beyond the seals. I have recently ridden the bike in rain, snow, and washed it in a bathroom with a showerhead.

The symptom that I am observing is the following. I just cleaned the stanchions, oiled them, compressed them rapidly to get oil beyond the seals, then wiped off excess oil and dirt, from the seals.

But unlike usually, when compressing the fork, there was a "whum" sound of air leaving the fork boots and passing throught some liquid at the seals.

On one hand, I had just put oil just there. On the other hand, I have never heared this sound (with a brand-new fork), when applying this procedure.

Should the fork be disassebled and dried? What other tell-tales are there that there is water in the a (spring-operated) suspension form?

The XCRs are very simple forks and unless specified don't have an oil or air damper so very user friendly.

It is possible that water has got below the dust wipers but this is generally unlikely.

The mechanism for a XCR is a sealed lock out unit and a coil. You should simply be able to drop the lowers off the fork without disrupting anything else to check them out for water and to ensure there's plenty of grease to protect the spring and other internals.

The 'whum' could be the stanchions being a bit sticky moving through the wipers but not much else I can think off.

I have a SR Suntour XUE 30 and I've washed the bike because it was dirty. After it dried I turned it upside down and compressed the fork and the water started to come out of it and I've done it few times to get as much water as possible. I'm not sure what to do now so it won't be damaged by the water inside in the future...


What kind of German bike is this? I want to buy this second-hand bike but the person selling it lives in a different city and I can't go there at the moment.
However I can't explain it but I really like the bike even though I only have this picture of it.
I would like to know if any of you recognize the bike.
The only thing I know about it is that the bike is German.

OP's answer-as-a-comment:

  The bike was not german, it was japanese. I found that the derailleurs were made by DNB Japan somewhere around 1960 and that the handlebar is french (Guidon Phillipe), but other than that , this bike is a mistery to me. The brakes only have a logo on them and the frame has only a number and a logo on the back. Underneath all the black paint, in the front, is a sticker but there is no way I can peel just the paint without damaging the sticker... On the pedals it says Lyotard 82 and they are in a rather good condition.

Thus, it is not identifiable.


Best Tires for Cannondale Bad Boy 4 I'm just getting into biking and last week I just purchased a Cannondale Bad Boy 4 from REI. They still have it in the shop as I'm in the processing of moving and they agreed to hold onto it for me.

My question is regarding tires. I purchased the bike as an urban commuter vehicle as I've just moved downtown and am planning on using it for my commute to work. I also plan on taking it on some longer rides now and then on the city greenway (paved path), to get groceries, or to see friends. Nothing super long, maybe 10-20 miles max. The vast majority of my trips will be much shorter though, 1-2 miles through downtown.

I noticed the bike comes with "smooth" tires (not sure the right term for them), which appear (to me) more like long distance touring tires or something. Should I ask REI about switching out the tires with something with a bit of tread? I'm a bit concerned about running into rain on my commute and slick conditions.

The guy at the shop told me that the ones on the bike "should be fine" for what I'm looking to use the bike for and that I should just be sure to be careful in wet conditions. He said if I wanted to, I could get some "gator skin" tires down the road to have as another option. But I don't think I'd be interested in storing and/or switching out tires on my bike. I'd rather just have one set of good tires and stick with that.

Anyhow, what do you think? Based on my situation, should I stick with the smooth tires or see about switching them for something with a bit of tread on them? I'm more concerned with safety than lightning speed. Thanks for any insight!

Bikes don't have enough speed / surface area to hydroplane.  A slick does as good as tread in the rain.

The responses saying slicks are just fine are mistaken. I recently had a nice accident sliding on some wet pavement that I shouldn´t have with normal tires.  Nope... don´t know why Cannondale went with these as the default.This is supposed to be THE monster urban bike.


How To Prevent Holes Around The Inner-tube Valve? In the last two months I have experienced something new: three inner-tubes (700X25) have popped with holes immediately around the valve and on the same side of the tube as the valve. I suspect there is a deficit of support for the tube as the hole in the rim for the valve is slightly larger than necessary (1-2mm bigger in diameter that I would think best). Should I replace the rim-tape? How may the proper support be imparted to the inner-tube around the valve?

I had a spate of these; all the tubes had an elliptical, smooth rubber section immediately around the valve, and then a weld joining this to the body of the tube. The failure was always at this weld, and it looked as if the tube had herniated (bulged out in a single spot before bursting there).

After ruling out tape problems, burrs, sharps, valve hole diameter etc. - I finally figured out the problem.

The elliptical section is less flexible than the main body of the tube, so after pushing it above the bead as Zippy suggests, it wasn't fully descending to sit flush against the rim. This left a void between the rim and the less-flexible part of the tube around the valve; the more flexible section of the rim then tried to expand around the weld to fill this gap, and that's where it burst.

The solution is (touch wood) to pull the valve back down after the tyre is seated and the tube partially inflated, and tighten the nut more than usual (and then slacken off).  When the tyre is fully inflated, double-check that there is no bump near the valve, that the bead is seated properly there, and that the valve doesn't move if you tug it towards the hub (not too hard!).

I placed a large tube patch (centered over the valve) along the area where the tube quickly wears.

YES, NEVER install the nut when inflating a presta tube...you want the valve to stay far from the tire bead when inflating. If valve nut is installed before inflating the tube, the tube will blow at the valve area.


One crank arm won't come off First time taking the cranks off. The bolts, chinrings and drive side came out easy. Left is stuck. Should I open, pull or do something particular for it to come out?

You must use a Crank Arm Puller tool:

Park Tools Crank Arm Puller

Here's how to use it:
Video

In addition to the answer provided by CQH, You could also get the crank off by putting the other crank back on (not very tightly), removing the bolt from the stuck crank, and riding a bit.

The crank should fall off after a little while, especially if you do bunnyhops and other things that put a lot of torque on the cranks.

This may not work with your octalink setup. I've only done it with square tapers.

This is a hack, and I wouldn't do it if you've got expensive cranks, but it's a good option if you don't have a crank puller.


Changing the cassette: is it necessary to change the rear derailleur and/or chain? I recently moved to a city with a lot of steep hills so I'm looking to change my 11-28 cassette to this Shimano Tourney 14-34. I have a Shimano Tourney rear derailleur with the same number of gears (7).

Since the biggest gear (34) in the new cassette is a lot bigger than the one I currently have (a 28 teeth) I was wondering if I could still use my old derailleur.

OK, from my research, and the other answers, this are the steps you have to take to change your cassette:

Determine if you have a freewheel or a cassette? This is a distinction that I initially ignored. It is important because you need different tools to remove and install these, so be careful.
Find your derailleur model, it is usually engraved in the back of it (mine is a Shimano Tourney RD-A070) and google the maximum sprocket that it supports. For my derailleur, it was a 28 teeth gear, but I managed to make it work with a 34t. As always, manufacturer specifications are a little conservative.
Adjust the b-screw in your rear derailleur: here is a How-to tutorial

            . Doing this you'll be able to adjust it for a bigger sprocket.
Using the model of your derailleur, google its capacity. The capacity is the difference in teeth from the gear in which the chain is loosest (the smaller chainring and the smaller rear sprocket) to that in which it is tightest (the biggest chainring and the biggest rear sprocket).

If the capacity of your rear derailleur is lower than your actual capacity, I think you can solve this problem by avoiding ever cross-chaining.

This is what I have been able to come up from zero knowledge about this, so, please, correct me if I am wrong in any of the above.

Derailleur: You don't need to change your derrailleur, it will be just fine.

Chain: You only need to change your chain in two situations:

You've ridden more than 2000 km with the last one. That would mean it will not properly grip to the teeth on the new cassette. The old combination worked because the cassette and chain have the same amount of wear, thus having the right shape of teeth for the old chain.
As pointed out by @CRoberts, there is the chance of your old chain being too short for the new big ring. In this case, just change the cassette and see if it works.

I do have a road bike equipped with Shimano Claris, and recently did basically the same conversion as you want to. Claris rear derailleur is shorter than Tourney, and my new chain (as both cassette and chain were extremely worn) is even shorter than the original. Worked like a charm in the small chainring. In the big chainring I have to be careful to not use the biggest cog, as it makes the derailleur extremely stretched.


How many miles should I ride each day to prepare for a 66 mile ride in 6 days time? I have been riding my bike for years and I am a very experienced rider. I am also in great shape.

I am a 15 year old girl. I have one week to prepare to do a 66 mile bike ride with a mountain bike frame and road bike tires (I don't know if that's considered a mutated bike or not).

Please let me know! Thank you.

Honestly?  6 days is a bit late to do anything significant.  You should probably do ~5-15 mile rides for the next 4 days, and have at most a short 2 mile ride on day 5, and then you've got your event.

Try and do your rides on similar terrain/roads if possible.   Ideally you'd do pieces of the real road - they always feel "shorter" on subsequent trips.

Don't get carried away with replacing major mechanical components this close to the event.

Your best bet is to do basic bike maintenance, like lubing the chain and tweaking the gears and brakes, and inflating your tyres.  Check out your spares and on-bike tools, make sure its all good and that the spare tube has not acquired a hole.

Also - if your event is self-supported, you'll have to carry 66 miles worth of water and food.  You'll need to pack that onto your bike in a way that doesn't interfere with riding, be it camelbak or frame bottles or panniers or whatever.

If the trip is supported (ie, feed stops every hour or 20 miles) then its lower importance but still don't run low.  Sometimes the fueling stations aren't there or have run dry, (or blown away!)

Finally, plan on how you're getting home.  Noone wants to ride another 66 miles back home after such a trip!

Lots of good advice. One more tip. When I used to ride my flat bar bike my hands would become numb. Turns out lots of people have this issue. The solution for me is to keep my wrist as straight as possible. In other words keep the back of the hand parallel to the forearm. Also keep your elbows slightly flexed.


Is cycling with crystal sunglasses dangerous? I'm a commuter cyclist. I have a pair of Persol sunglasses with leaded crystal lenses. Do y'all think this is dangerous in case of an accident? I have terrible thoughts of wrecking and glass shards going into my eyes, but I'd rather not carry two pairs of sunglasses. Thanks in advance for your answers.

Edit to respond to below comment because I can't comment yet: I don't know their behavior when impacted... that's kind of what I'm getting at with this question.

Richard

I have had my glasses damaged when falling off/getting hit on my bicycle, even with a helmet. Since my lenses are polycarbonate, they tend to just bounce on the road if they do come out of the frame. I'd think in some of those hits that my glasses would have broken if they were made from glass (especially when my glasses have hit the curb or rocks).

Based on this experience, I wouldn't risk using glass based sunglasses on a bicycle if I had the option. You can find safety glasses which act like sunglasses for a relatively low price, which don't look bad (e.g. the Uvex SafetyPro line) [but note these are likely not tested for sports, but are designed for some level of safety].

The best person to ask would likely be an optometrist or eyeglass retailer (the former likely being less biased than the latter) on what they would suggest for sports. This article (Cobb, Clark, and Chad Hulsopple. "Eye injuries in athletes." eMedRef (MU) (2010).) suggests use of polycarbonate for sports.

When the first words used are "I personally don't think" I would tend to take the subsequent advice with extreme caution. There are well-established criteria for safety glasses that opinions do not circumvent, which many brands like Oakley meet or exceed in their entire lines of sports eyewear; they also have separate lines for ballistic protection, which meets much higher impact velocity standards for military/shooting protection. ANSI Z87.1 should be the minimum for safety, as both shatter resistance and impact penetration from things like rocks kicked by passing cars can go right through the wrong plastics, and no type of glass is safe. Falling can also shatter bad eyewear, and long shards of glass or plastic can blind you - an extremely poor tradeoff in cost and fashion vanity. Those tests on YouTube are the real deal, and you can't judge just by looking at a pair whether they will protect or not.
As an aside, I'm doubting the worth of this stackexchange experiment, as too much of the advice seems to come not from those with insider knowledge, but from people just spouting opinions free from even personal anecdotal experience half the time. Honestly, when it comes to technical advice, some opinions are worth a lot more than others, and having to read through the uninformed when life or health is at stake, and try to differentiate good from bad makes for a very inefficient forum paradigm.


Why is my fixie so very hard to pedal? I recently got a fixed gear bike and I rode it about 5 times. I live in an urban part of the city. I've never rode a fixie before or know much about bikes in general and I knew it would be difficult to ride a fixie since it's only one single gear and you can't stop pedaling.

I did notice how hard it was to pedal at first but after a few blocks I would get so tired I'd have to get off the bike to rest, especially against the wind sometimes. Now when I ride it takes a lot of leg power to go but then I become so tired after riding for a little bit. Is this normal? Does it take getting used to riding a fixed gear? Or is there something wrong with my bike.

I just think it's not right that a bike that a lot of people claim to say that it's the best easy to ride bike can make me unbearably tired after riding it for a few blocks. I just want to know why this is happening and if it's normal.

There's not really enough information in your question to tell for sure what the problem is, so let me just list a few possible explanations that come to mind:

As others have noted, your gear ratio might just be too high for you (since you say it takes a lot of effort to get going).

You can take your fixie to a bike shop and have them swap the rear cog for a bigger one and see if that helps.  While at it, you can also have them check for other problems, too.
Something (like, say, the brakes, if your fixie has them) might be dragging against the wheel(s), slowing you down and making you work hard to keep going.  Or, just possibly, there might be something wrong with your wheel bearings, causing the same effect.

There's an easy way to check for this: just flip your bike upside down, give the pedals a quick spin with your hand, and see how long it takes for the rear wheel to stop spinning.  Then do the same for the front wheel, too.  (You'll have to spin the front wheel by pushing on the spokes directly.  Be careful not to let your fingers get caught between the spokes and the frame while doing so!)

On a well-oiled bike with decent bearings and nothing dragging against anything, the time to stop should be measured in minutes rather than in seconds, and there should be little if any noise.  (That goes especially for a fixie, where you don't even have the ratchet mechanism ticking.)  Certainly, there shouldn't be any grinding or scraping noise, and the wheel should certainly not stop in less than ten seconds.
If you're used to freewheeling bikes, you might be unconsciously trying to slow down your pedaling after you get up to speed.  On a freewheeling bike, that lets you relax and let the bike roll along — on a fixie, it brakes the bike.

There's no simple fix to that, other than switching back to a freewheeling bike.  If you want to keep riding a fixie, you'll just have to unlearn that habit.  Fortunately, simply with enough practice, that will probably happen naturally.
More generally, you might just be unused to riding a fixie.  It does require a somewhat different set of muscles and riding behaviors than a freewheeling bike, and so you might initially find yourself putting a lot of stress on muscles you're not used to using so hard.  Your description sounds a bit extreme for just plain unfamiliarity, but it certainly might contribute, perhaps together with an excessive gear ratio and/or poor riding position.

Again, this is something that will only be fixed by practice.  After ruling out (or fixing, if necessary) all the other issues, just keep riding regularly and see if it starts feeling any easier.  If yes, you're making progress, and should keep practicing until you can ride your bike comfortably.
Also, make sure to check your riding posture.  A poor posture can make riding a lot harder than it needs to be.  This is true also for freewheeling bikes, but it's particularly true for a fixie, since there you can't just stop pedaling to rest your legs.

In particular, check that your saddle is not too low, as that seems to be a common error.  Ideally, when sitting on the bike with the pedal is at its lowest position (i.e. pointing at 6 o'clock), your knee should be just slightly bent.  (An angle of about 25° short of straight seems to be commonly recommended.)  If your seat is too low, you get less power on the downstroke, and have to expend extra energy to lift your leg on the upstroke, making your legs tire faster.

I have been riding a Fixie for years.  My bike has a gear on each side of the hub.  (One poster called it "a flip-flop hub"}  One gear is fixed (no coasting or pedalling backwards) and the other gear is not fixed (allows coasting and pedalling backwards).  It is easy to turn the wheel around.  Just loosen two nuts,  move forward to create slack and take the chain off the gear.  Be aware that some tires have a rotation indicator and in that case you would have to deflate the tire and take it off the rim to turn it in the proper direction.


Getting a tire off the rim - 37-622 Ive tried everything and can’t seem to get the tire off the rim. I’ve double checked the bead and it’s loose. I pushed the beads into the centre.  I’ve tried warming up the tire. It almost seems the tire is smaller than the rim. I try and use the tire leaver to lift it but it almost seems to grab both beads at the same time. I can’t lift one bead up over the rim edge. I really don’t want to take it into a shop as I’ve changed other tires quite easily. I also tried the front tire Incase it was just an issue with the rear one I was working on. Natta. Any suggestions?

Soap and a bunch of muscle power did the trick. Thanks so much everyone.

Counterintuitively, one pump of air in the tube may help separate the two beads of the tyre, allowing you to grab just one with the tip of your tyre lever.
I have a bunch of tyre levers, and some are good while others are dreadful.    See if you have one with a flattish front, not a spoon or bill shape.
It can help to use some cable ties or velcro straps to squash the tyre into the rim's internal valley.  Then work your way around the tyre pushing the whole thing into the rim whilst moving the excess around the circumference to the opposite side.  This is generally how one would fit a new tight tyre like a Marathon.  You're doing the same process in the same order but aiming to get the bead off.
Last resort, if the tyre's dead you can cut it off but this means the tyre can't be reused,

You need a tire prying tool. Please make sure you remove the stem and the valve before removing it. If it is not possible go to the repair facility it will be simple and cheap.


Hydraulic disc brake - lever compatibility I purchased a gravel bike with drop handlebars, mostly for commuting and maybe for some weekend bike camping trips.  I've only ever ridden mountain bikes with flat bars in the past, but I figured I'd get used to the drop bars.  After a month I'm realizing that drop bars are just not for me.  So I want to take my Jones Loop off of my MTB and put it on the new gravel bike.

The gravel bike had Micro Shift MTB bar end shifters so I picked up the matching flat bar adaptors for $40 and that will be a real easy 10 minute switch.  Now I just need brake levers but I can't seem to find definitive answers online about which ones will be compatible with my brakes.

I've never bled a brake line before but I'm confident that I could do it and its only another $20 for the line bleeding kit.  More than one blog says that there are not many compatibility issues with hydraulic levers when switching from drop bar to flat, but I can't find anything that says if I can just use any random hydraulic levers with these brakes.

The brakes on the bike are TRP Hylex hydraulic disc brakes.  From what I can tell, TRP only makes one flat bar hydraulic disc brake set and they don't seem to sell replacement levers.

I don't need top of the line parts, but I don't want to buy something that is going to break easily.  I found a store selling what look like very basic levers, Shimano BL-MT200, at $15 for the set.  I also found a list of other Shimano levers at varying price points, BL-M6000, BL-M7100, and BL-M8000.

My questions are:

Can I just swap out the TRP Hylex drop bar levers for these cheap Shimano levers?
Could I hypothetically use just about any random hydraulic levers? SRAM / Tektro / Shimano
Does it make good sense (would I notice a difference) to buy a more expensive lever like the BL-M8000?

An important reason why you can't randomly mix and match hydraulic brake parts is because different manufacturers use different hydraulic fluids. SRAM uses DOT 5.1 brake fluid. Shimano uses mineral oil. Campagnolo uses mineral oil. Using the wrong kind of fluid can damage the seals.

Can I just swap out the TRP Hylex drop bar levers for these cheap Shimano levers?

Unlikely to work, not recomended

Could I hypothetically use just about any random hydraulic levers? SRAM / Tektro /

Technically, no. The issue is that the lever and caliper together need to provide the correct leverage ratio between the fingers on the lever and the pad on the rotor. That's set by the relative cross-section areas of the pistons. If you have a mismatch you either get too much force but not enough pad movement, or too much pad movement and too little force. You cannot guarantee that different manufacturers have so happen to have chosen compatible piston areas.
There is no documented general compatibility between road calipers and MTB levers. Shimano's compatibility documents show no compatibility between their road and MTB brake components, and neither do SRAM's.
Your best course of action would be to replace the levers and calipers, so you know you will have brakes that work properly.
Shimano makes hydro brakes in their lower-tier Acera (where the BT-M200 sits) and Alivio lines which would probably be fine for your purpose. You could also use equivalent Tektro flat bar brakes.


How to you remove the seal from a Deore XT FH-M8000 freehub? When first installing (or overhauling) Shimano rear hubs, I usually pull the freehub, lift the seal off the back side (where the splines are that engage the hub body) and then heat the freehub with a heat gun. When the old lube flows out, I drip in enough Phil's Tenacious oil to keep the things utterly silent. I love silent coasting. I have had no trouble doing this with Deore LX freehubs and others, but the FH-M8000 XTs I've got don't seem to want to give up the seal. Usually, gently picking the rubber seal with a large (not too sharp) sewing needle lets you pop it right off, but these don't seem to want to budge. Anyone out there pull one of these rear seals and know how it's done?

I would take the hub to your local bike repair shop. More than likely they will pull out a special tool just for this issue of your seal not wanting to unfasten itself.


How does weight influence your speed when descending? I have recently bought a road bike and went on a little trip with a friend who is also a novice.

We have approximately the same height but he weighs a lot more (I weigh 67-68kg for 1m81 and he weighs around 80-85kg).

While descending a road, he outclassed me easily. It made me wonder :

Suppose that two people have exactly the same characteristics (same bike, same height, same equipment,...) but a different weight and a corresponding different shape (one is fit and the other overweight or more muscular). If they both ride perfectly (i.e. in an optimal manner), who is going to go faster ?

If the road and tires were perfectly smooth and there was no air, physics tells us that these two people would go at the exact same speed.

Theoretically, the heavier person has a less aerodynamic shape if his/her additional weight is the result of fat and not muscle, so if the road and tires are still perfectly smooth and if there is air, the lighter person should be faster (assuming that the "aerodynamic theory" is right).

Now, add the fact that the road and tires are not perfectly smooth and that I have probably forgotten important factors, how to know which one will be faster ?

I could have asked this question in the Physics community but I bet it is something known in the bicycles one.

The heavier person will present more area to the wind, but this is mitigated by two factors: The bicycle presents a fixed area to the wind and the area presented by the heavier person is not proportional because of the 2/3 power law. If you just scale up a rider by a factor in mass, the volume increases in proportion, but the frontal area scales up as the 2/3 power of the weight ratio because the dimension along the direction of travel does not contribute.  Both of these mean a heavy rider on a bike with a constant grade will descend faster with no power input besides the hill.

Assuming you both have the same shape (but he has more density, so he weights more):

If there were no air, both of you would drive at the same speed, due to the gravity acceleration (the same for both).

If there were usual atmosphere, you both would be accelerated downwards due to gravity (same acceleration), and your aerodynamic drag force would be the same (you have the same shape, and - in the beginning, at the comparison moment - at the same speed).
As force accelerates you proportional to mass, drag would decelerate less than your friend, so he would reach greater speed.


Urban rides map projects Some time ago I read about a project in which bike commuters tracked their paths in order to map then on-line and have a place to see the most frequent routes in their city. Do you know this or other similar projects?

Strava has a heatmap function you can enable on their route planner.  This will show the more frequently used streets and will vary intensity of color based on popularity.
http://www.strava.com/routes/
Garmin Connect also has a heat map functionality built in to their route planner.
http://connect.garmin.com/course/create
The garmin maps seem to be more effective in heavily used areas like city center and heavily trafficked trails, while strava seems to be a bit better at showing a bit more detail in both city and rural areas.
May also want to check out Race Shape's heat map, which seems to be a worldwide bike based heat map. Race shape pulls data from strava and ridewithgps.com to create these heat maps. http://raceshape.com/heatmap/
(Strava has taken over Raceshape and incorporated it in their premium product.)

There's an android app mapmyride which sounds similar to what you want.   It may also be on  the  iPhone


What are the advantages of angling your saddle down? I have seen a few people do this where their saddle was angled down a bit. Why would someone do that?

In general, I don't know why one would do this. Especially men.

Here's what Sheldon Brown has to say, and I tend to agree:
"If the saddle is tilted down in front, the rider will tend to slide forward onto the narrower part of the saddle. Women who are riding on saddles that were designed for men frequently tilt their saddles down. This will relieve some of the discomfort from the saddle itself, but creates new problems: The downward slope of the saddle causes the rider to tend to slide forward, and this can only be counteracted by pressure on the hands. Thus, poorly-angled saddles often are the cause of wrist, shoulder and neck problems, due to carrying too much of the rider's weight on the hands."

Lennard Zinn mentions that a "very slight" tilt in either direction may be optimal for some riders; but no more than ~2 degrees. Basically the same reasons that Sheldon Brown mentions. The downward forward tilt adds pressure on the arms, back, and shoulders due to sliding forward.

You want your "sit bones" to be on the widest part of the saddle. If you slide forward, the pressure will shift from the sit bones to the perineum; and that's probably a bad thing. There are special cases for tilting the saddle nose downward; but for the general rider it's not necessary.

Because I like it that way. Tried the tilted down position many years ago and have never had any reason to change it.


Should or can I (car) wax my frame? Having spent the whole summer taking a bike apart, painting it and now in the process of building it again, I was thinking about waxing it. I want the finish to last as long as possible, after all, I've spent sooo many hours on this project.

Would it help in anyway? Protecting the finish etc.
Or could it instead harm the bike?

Using car wax on your frame could certainly help protect it over time, though storing it indoors is much more important so that all of the components are protected from the weather.

There are bike specific products like Pedro's Bike Lust but if you don't want to go that direction you should be just fine with any auto wax. In the past I have heard of people using furniture polish as well to give the bike that just out of the shop shine.

You will want to avoid the harsher products that contain aggressive abrasives like rubbing compounds, especially if you have carbon portions of your frame, as these will remove the clear-coat and can lead to damage or failure.

wax(carnauba) will not harm paint fullstop...there is not cleaner agents in carnauba....cured paint is only down to the hardness it forms so to say not too wax or seal a fresh paint job is silly...would you not seal a new car...i know plenty of detailers do the full multi stage machine polish and finally seal new cars or fresh paint jobs....paint will cure over time no matter what you do...but if u want to protect it i would advise in using a wax or sythetic sealant that has no silicone in it...silicone is paints worst enemy...it stops pores in the paint from breathing....i use a ultra fine polish just to bring the shine up with little effort the seal it with a sealant then a coat of carnauba wax...the same way i treat my car without the machine polishing aspect....thatll last 6mths easy...just wash it whenever and apply another coat if u like...or use citrus degreaser (or fairy liquid)on the whole frame and thatll strip the wax right off...hope this helped


Adjust reach on Ultegra ST-6510 levers? I'd like to adjust the reach (distance from the drop bars to the brake levers) on my Ultegra 6510 levers.  The Shimano instructions don't mention the ability to adjust this at all, which seems odd to me, since even basically junk mountain bike levers are adjustable in this way. Is there a way to adjust this on these levers? Is it "normal" for road levers to not be reach adjustable, or is this just a Shimano thing? From searching around a bit, it looks like you can use "Specialized Slim Shims." Is that the way people typically adjust the reach? Anyone have any better "home-brew" way to make them adjustable?

The Specialized shims are probably what you will end up using, however, before ordering them up, see if there is anything you can do by changing the location of the levers on your handlebar.

Drop handlebars can be adjusted in a multitude of ways. You can adjust the overall angle and slide the levers forwards or back to compensate for a change of bar angle, to keep the hood position where you are used to it being. Sometimes you can push the levers mounting position forwards/down, to interact differently with the curve of the bar to give a shorter reach. How exactly this works with your bike depends on how 'anatomical' or 'track style' your bars are. This will involve a lot of adjustment of bars, levers, cables and tape, but it is something you may want to investigate.

Alternatively go with the Specialized shims or simply rely on the fact that you can always reach your brakes if the threat is scary enough and slacken them off a bit so that, once you have got the lever, you are not working it with your fingertips to effect useful braking.

Most new levers are adjustable. Check out this video:

http://velonews.competitor.com/2014/09/video/ask-mechanic-adjusting-reach-road-shifters_347208


Front Mountain Bike Cable Disk Brake Is Too Snappy on First Pull When I grab my front disk brake for the first time on a ride after my bike has sat for a while it will buck me forward.  Once it bucks me it works great.  I have tried cleaning it with disc brake cleaner but I have not seen any improvement.  Any help is appreciated.

I  removed my brake pads and sprayed the pads and disk with some good cleaner and so far it has been a success.  Thanks for the help.


Why are trigger shifters so widely used, instead of the twisting grip shifters(revoshift)? I recently rebuilt my whole bike. It was in terrible condition. I also decided to get a new freewheel with more speeds. While i was doing some research and looking through shifters and freewheels, i found out that the twisting grip shifters were limited to only 6 and 7 speeds. I couldn't find any twisting shifter with more than 7 speeds. I personally find them so comfortable, convenient, easy and way faster to shift than the common trigger shifters. I finally decided to get rid of the old 6 speed freewheel and install a brand new 7 speed freewheel with a huge low gear for crawling.
Why are trigger shifters so widely used? I don't see any advantage.
Update: Many people said that twisting grip get stiff over time and are difficult to twist. Yes they get a bit stiff over time, but from my experience they still aren't hard to twist at all
Below image of twisting grip shifter

In the context of a high-end MTB designed to go quickly over difficult terrain, trigger shifters have the following advantages:

They can be operated using only the thumb, without changing the grip, so the index finger is always ready to brake.
Getting mud on the gloves does not impair operation.

Modern grip shifters do exist, Sram makes a wide range of those, and in my experience, the cheapest option (the GX model) is very reliable and performs very well. For completeness sake, grip shifters have the following advantages:

Ability to shift through the entire cassette in one motion (assuming a single chainring setup, typical for the context), useful before a sudden steep hill.
Absence of a protruding element to be hit by the knee in case the leg unclips unexpectedly.

Why are trigger shifters so widely used?
I don't see any advantage

I don't see any disadvantage.
Trigger shifters are very cheap and easy to use. They can be used during a harsh winter when you have so thick gloves on that your effective finger size is multiplied by a factor of 2-3 as thick gloves don't make operation difficult. They aren't (usually) coupled to the brake lever so you can choose your brake lever and shifter separately. They allow you to downshift multiple gears at a time. They probably work more reliably on a slightly out-of-adjustment drivetrain as downshifting involves a small amount of "overshifting" and then releasing the overshifted cable to fall back to its rest position. In contrast, grip shifters don't overshift. Thus, they are more likely to function less well on a drivetrain and cable system that's a bit out of adjustment: perhaps the rear derailleur hanger isn't straight, perhaps the rear derailleur bushings have worn, perhaps the cable has more friction than when new, perhaps the bottom bracket cable guide is full of dirt, etc.


Buying brake levers, how do I find the correct ones for my bike? I took a hard spill the other day on my mountain bike and snapped my left hand brake lever in to pieces.
The ones that snapped are stock alloy rubbish that came with a Specialized Hardrock 2010 Disc Brake model.   They are standard Bowden Cable brake wires with the little barrel shaped bit at the end that fits to the brakes.  (Do they have a name?)

I'm having some trouble purchasing levers and there doesn't seem to be much information on it online or much information on the products I'm finding.

To the point

What I need is Bowden Cable compatible brake levers but I have no idea how to search for them.  Sometimes descriptions will mention that they are for pneumatic, V-brakes, caliper or canti brakes but I've never seen anything saying that they would be compatible with my bike on any site.

What am I doing wrong? Or what should I be searching for here?

Since it sounds like you have mechanical disc brakes (Avid BB5 or Tektro Novela not hydraulic) then any direct-pull or V-Brake lever should work fine with your cable. Searching for 'V-Brake levers' or 'mechanical disc brake levers' should provide plenty of responses.

For example, if you look at the spec page for the Avid FR-5 lever, you will see that they are compatible with both "Mechanical disc brakes, Linear-pull brakes." V-Brakes are a type of linear-pull brakes.

Note that most levers designed specifically for Cantilever Brakes will NOT be compatible. The key issue is that the levers must be direct or linear pull.  Some brake levers (e.g. Shimano's ST-EF60 shifter+brake lever combo) are switchable between canti's and V-brakes. If you don't set them to V-brake, you're not going to pull enough cable for proper braking.

Look at the setup. Determine if they are V-brakes or cantilever or disc. Only cantilever takes different levers. Cantilever brakes are pretty old so unless your bike is at least 20 years old then you probably have a v-brake or disc. Any vbrake will work for a disc set up as long as they are mechanical, not hydraulic discs.


How much cycling distance is needed to travel every day for good muscular exercise? As a bicycler I used to travel on cycle daily for about half an hour to maintain fitness of my legs and body.
But I want to know how much time and distance is needed for a good exercise.

As individual speeds vary depending on fitness, bike and conditions, most information on this subject discusses intensity and time spend exercising, rather than distance. Most leisure cyclists ride between 10-18mph (16-30kph) on the road, a bit less off-road. As you can see it's a fairly wide range, so time and intensity are better measures.They can also more easily be applied to other sports.

For good health, the WHO recommends:

  Adults aged 18–64 should do at least 150 minutes of moderate-intensity
  aerobic physical activity throughout the week or do at least 75
  minutes of vigorous-intensity aerobic physical activity throughout the
  week.

If you'd like to improve your cycling fitness as well as your health, then British Cycling has a number of beginners training plans, depending on what you would like to achieve.

However, not everyone responds the same way to exercise, so the improvements are not guaranteed.

As a bicycler I used to travel on cycle daily for about half an hour to maintain fitness of my legs and body. But I want to know how much time and distance is needed for a good exercise.

Depends on what your goal is.
If your goal is to get strong muscles, I suspect half an hour of hard riding, riding on a hilly terrain, sprinting from stoplights, climbing hills standing is enough. A 3-hour ride won't develop your muscles more than a half-hour ride would do, because the last hours you are anyway so tired that your average speed drops and you aren't using the full strength of your muscles anymore.
If your goal is to reduce weight by burning fat, I would suggest to allocate much more than half an hour for your ride. Start to ride to some direction. When you start to feel exhausted and your average speed drops, start to ride back using the same route. This way, half of your cycling time is done when you are exhausted. This is important: fat releases energy slower than carbohydrates do. To burn fat, you need to exhaust your supply of carbohydrates first. The exhaustion occurs because your supply of carbohydrates stops and energy comes from burning fat.
If you carefully calibrate the length of your trip so that you will be back at the moment you start to feel exhausted, you won't lose much weight. The important part is that you have to ride when feeling exhausted, to lose weight.


Touring tires and fixing flats I am riding the Florida Keys Overseas Heritage Trail (FKOHT) in February 2021. There will be flats. The ride is unsupported. Most riders say they have at least two flats on the ride, some riders have as many as 8! I use clinchers and tubes. I admit freely that I am a weakling and cannot get some tires on the rims without using a Koolstop tire jack, which I do carry with me on the bike. The Koolstop tire jack is not perfect, but it mostly works for me.
Whats the best strategy? Use a tire with flat protection that I will have to wrestle with and use the jack if I get a flat? Or use a tire that I can mount by hand, but will probably have less flat protection and one that will likely result in more flats?
Or is it just a matter of using a tire I like and stop over-thinking? I would like to spend my time riding, not fixing flats.

Questions related to ease of mounting can be nebulous to answer, because usually much more than any other factor, what determines how difficult a tire is to mount is the tolerances of the rim and tire. The most difficult mounting situations occur when the bead seat diameter of the rim happens to run large, and the bead diameter of the tire runs small.
There are some known models to avoid if mounting ease is a priority, but there is no totally reliable way to buy a tire that's easy to mount, because tolerance problems can strike randomly. Light, supple tires  mount easier on average, but it's not a guarantee.
Some highly flat-protected tires are notorious for being difficult to mount. As pointed out in the comments, the Schwalbe Marathon Plus has become a poster child for this. The reason is that, especially in narrower sizes, the massive amount of casing armor makes it difficult to get the beads sunk in to the rim well so that the section of tire 180 degrees away can be pushed over the rim and seated. They're also stiff and can be hard to even wrangle the first bead on.
I think that as long as you have still have the ability to reinstall the tire when needed, using a bead jack if necessary, it makes more sense to just choose something tough enough for the roads you'll encounter and the loads you'll be carrying. Unless it's thorns/goatheads/cacti/etc you're worried about, the stuff that gives you flats in a lot of flat-prone areas can also damage or destroy tires. Undergunning it carries the risk of a tire getting sliced instead of simply punctured, which is the kind of damage that the overbuilt casings of proper touring tires are good at mitigating.
If you do want to have some insurance against punctures that won't make any difference in mounting difficulty, you could also use tubes with sealant in them. Sealant has downsides, but can work well in areas plagued by thorns and goatheads, and makes a little more sense in an event ride type context than day-in, day-out.

There will be flats

Don't be so certain.
This is a 171 km long route. In the last 1500 kilometers (1000 miles), I have not had a single flat. I use extremely thin racing-style tires with no protection at the sidewalls and practically no puncture protection (since you can't reasonably sell a tire with absolutely no puncture protection today, they have to add a bit of it and advertise it as a "puncture protected" tire). In those 1500 kilometers, I have ridden often through a tunnel that most of the time has broken beer bottles.
I weigh so much (110 kg) that the narrow 28mm tires I use are working near their limits. In fact, in my use a wheel having less than 36 spokes will have its nipples unscrew. I have not had any pinch flats recently despite this. The tires I use are not tubeless, they are traditional clinchers (so at least in theory they are susceptible to pinch flats).
What is my secret, then? I watch where I ride. If there are broken beer bottles on the road, I evade them. If there are any irregularities in the road, I stand on the pedals in the fore-aft position and put my arms to 90 degree angle so that both my legs and my arms are in an optimal position to take any road irregularities. Then the unsprung mass is just part of my legs and arms, and the bike. My main body weight is not part of the unsprung mass.

Whats the best strategy? Use a tire with flat protection that I will have to wrestle with and use the jack if I get a flat?

There are no tires that are fully protected against flats.
In particular, clinchers are always prone to pinch flats. No amount of "puncture protection" is going to change it.
About other types of punctures, the best approach is generally to use a tire-rim combination that allows mounting and dismounting the tires easily with standard tire levers, and then just fix the punctures when they happen. Any puncture protection that is thick enough to be effective enough (i.e. that it would prevent more than 90% of punctures) will slow you down so much that the amount of time you lose due to rolling resistance will be 10 to 100 times the amount of time you save to fix punctures. And remember, even if there was a puncture protection that is capable enough, it still wouldn't protect you from pinch flats.


Can hubs last forever? In theory, could a bicycle hub last forever if you kept overhauling it (and getting new spokes and rims and etc.)?

I'd like to know about all the hubs, but what really interests me is whether or not cassette hubs and front hubs can be overhauled over and over and last 'forever'.

If the shell is aluminum and we're talking about the whole thing and not just the bearing races, the literal answer is flat out no, because aluminum doesn't have a fatigue limit. It will crack eventually.

As to the question of can a hub bearing race, real or hypothetical, last literally forever in any kind of use, that's the kind of question everyone likes speculating about but I think you need a bearing engineer to begin answering, so I'll say I don't know.

In practical terms the answer is most cups/cones with enough preventative overhauling can be made to last a very, very long time, much longer than they normally do. In my experience for a nicer hub with very hard, precisely made races it's more or less indefinitely. I've tried to keep more modest hubs going the same way and wound up wearing them out despite my best efforts, but I'm heavy and ride where it's wet.

There's a side conversation about using ball bearings whose hardness is a good match for the races, which is a topic usually glossed over in bike shops. I don't know the details but I've come to suspect it can matter quite a bit in the long-term lifespan of a hub.

How much flex the axle is experiencing is also a pretty major factor over time.

All freewheeling mechanisms wear out eventually as far as I know.

Yes, in general they can, if they are overhauled when needed ( loose ball or cartridge bearings). And most importantly, the the hub bearings needs to be adjusted correctly, not too tight or too loose...


how much of a difference does bike weight make when trying to maximize the bike's top speed? Today I was at a bike shop looking at single speed bikes. I rode one, but didn't buy it because I like to bike fast, and this bike must have weighed 2x more than my aluminum road bike (the bike was steel).

The store owner told me that the bike weight will not have as great of an effect on my top speed as many other things both on the bike and things I could change about how I ride.

Is he right or wrong? Does bike weight make a big difference or is it just very good marketing?

The weight of a bike has virtually no effect top speed. It takes very nearly the same amount of effort to maintain a speed of 30 mph on a 20 lb bike and a 30 lb bike on flat ground. The biggest factors that come into play at high speeds are aerodynamics and rolling resistance ( slick, efficient tires ).

http://velonews.competitor.com/2012/05/bikes-and-tech/technical-faq/tech-faq-does-bike-weight-matter_220429

That said, is top speed what you're really worried about? Probably not. Even if you like to bike fast, I truly, truly doubt you should be concerned with top speed. You'll probably enjoy a bike that accelerates quickly and feels nimble. Unless you live in a flat, remote area, in which case you probably wouldn't want a single speed, you're probably going to be accelerating and maneuvering more than you are achieving top speed. And again, these factors don't necessarily correlate with the weight of the bike.

I love this question, and the answers are solid, but let me add that the weight of moving parts on a bike is more important than the weight of non-moving parts. So for my money, a heavier (read: steel) frame and lighter wheels is optimal. In addition, stopping an object with greater mass takes more energy, so if you've got those light wheels and some good weight on them, you can go faster, farther, with less effort.

That being said, and this is a personal tragedy for me, I especially like the point about the economics of losing weight versus buying a lighter bike. Very good but inconvenient point in my opinion.


Average lifetime for 26inch spokes I've been riding my bike for about a year and a half now and the back spokes are starting to snap, 2 now. I want to know when was this bike bought from the original owner since the spokes are stock spokes and it is second hand, it would be easy to know. All I do is just wheelies and bunny hops so maybe it might wear off more faster. Also, should I replace the spokes asap?

From the info you've given it's hard to tell how old your bike/the spokes are.

If the spoke tension is too low/if there is too big a difference in the tension of the spokes in the wheel this can cause premature spoke failure due to uneven force distribution over the spokes in the wheel. Make sure to have proper spoke tension/tension distribution to prevent premature spoke failure.

To answer your other questions:

1) Yes the wheels will not last as long when doing bunny hops and other such 'stunts' (such as riding down stairs, jumping off things etc.)

2) You should replace your spokes as soon as possible, if you don't and keep riding there is a significantly higher chance of more spokes braking (since the force is distributed over less spokes)

Your spokes are breaking because of your rim. You have already broken one spoke, your rim just suddenly got yanked to one side. Fitting a new spoke is a monkey patch on a cheap rim, and a temporary solution on an expensive rim, at best.

The reason for this is that now the rim is essentially permanently warped, spoke tension will be all over the placed and uneven, they will continue to break until your replace the rim + spokes. Tensioning the wheel won't do a thing.

The only exception is on carbon rims, where they basically can't warp, they just right out snap.


Is reversing the stem (pointing it backwards) a safe way to reduce reach length? Assuming a steerer/fork/brake/cable setup that does not rely on the stem facing forward: is it safe to point a stem backwards as a way to reduce seat-to-bar reach (i.e. as a way to 'fit' a too-large bike to a smaller/shorter person)? If not, why not?

No, it would not be particularly safe. The steering would get extremely twitchy and difficult to handle.

If you do not try this, you will never know how much more comfortable it can make your ride.

Danger is part of driving and riding anything.


Do mechanical disc brakes suffer from heat-induced fade? The other day I read a question about heat induced brake fade in hydraulic disc brakes caused by too much braking on long, steep descents, which is something I have also experienced when cycling in the alps. (A quite unpleasant experience, I might add.)
This made me wonder if mechanical disc brakes would suffer from the same problem. There is no fluid to start boiling, so at first thought they should be heat-fade-proof.

If so, I think an optimized disc brake system would have hydraulic activation of a short mechanical lever or wire connected to the caliper itself.
This way the system would optimize modulation (by minimizing elasticity) while still being safe to brake for extended periods.
I realize that even with mechanical brakes, you can't brake indefinitely, as the pads, calipers and discs would overheat at some point, but if the margin is large enough to cover most practical uses, the idea might be worth exploring.

So I'd like to hear from people with mechanical disc brakes if they have experienced heat induced fade?

From my experience, the answer is no. I have been cycling across the Great Glen and have no problem with mechanical disc brake.

My bike was moderately loaded with camping equipment. So the load (including me 70 kg) was around 110 kg or 242 lbs. There were continuous downhill sections but the brake works fine, thankfully.

From a scientific stand-point, there are three types of fade

Green fade - caused by resin boiling off of new pads
Fluid fade - brake fluid boiling and system losing pressure
Pad fade - pad overheats and loses friction

Ignoring 1, 3rd cause starts to occur at much higher temperature and require time than 2nd cause (which occurs at around 120 oC for moderately contaminated mineral oil*). That is why you need to check your mineral oil before setting out on a trip.

Pad fade is the main factor in Mechanical Disc brake fade. Unless you are not braking heavily and continuously for more than 10-20 minutes, you are fine.
In number, if you are going down 20% gradient hill, braking continuously to keep your constant speed at 18 kmph (11 mph), the braking power is around 1078 Watts for 110 kg (bike+load+rider). That means, referring to **, you can safely brake
for hours, if not hundred of hours for the iceTech.

Refer

*http://www.epicbleedsolutions.com/blog/dot-brake-fluid-vs-mineral-oil/images/shell-dot-fluid-boiling-points.png

**http://cycle.shimano-eu.com/publish/content/global_cycle/en/nl/index/news_and_info/Velotech_Disc_Brake_Test.html

i recently had a problem with cable pull hydraulic assisted brakes system, i admit me and the bike weighs in at 120kgs and i was braking from 60 km/h on a steep slope, but i experienced nearly total brake failure . It was very scary , the calipers were making contact to the disc, but i was not slowing down, even using all my force in gripping the leavers it did not help. I guess i had boiled the brakes, the discs had changed color a bit and steamed when i added water, from my water bottle !!
I imagine this is Brake fade at its most dangerous. I am now trying to go back to normal cable discs brakes. I wonder if rim brakes suffer from brake fad the way discs do =!?!?!


Fixed gear cranks loosening I'm new to fixed gear riding, and my bike only has a front brake. I have noticed that when I use resistance at the cranks to slow down, rather than the front brake, eventually the cranks will begin to loosen. I've tried thread-lock and torquing them down really tight, but they still eventually loosen up again.

(edit) It's a brand new bottom bracket and the cups are not slipping - it's the crank arm bolts that are coming loose. I will take a look at the crank arm interface to see if they are rounded off at all. It doesn't seem like it would be though, since once I re-tighten the bolts, the cranks are stable. It's only through the repeated "engine braking" that they get loose.

Is this just a thing that fixed gear riders deal with, is it a mechanical defect, or am I doing something wrong?

I guess your bottom bracket is a standard square taper?  And that your bike is getting a little old in years?  The fix is to replace the cranks.

The cause is that as you tighten the nut, the square taper hole on the crank mashes up close to the axle.  But as you pedal, and brake in your case, the cranks will minutely flex in the hole which creates a tiny space so fretting can occur.  This is when minor amounts of metal are rubbed off the inside of the crank's square hole - the bottom bracket axle is normally tougher than the crank metal.

Once there's a bit of play in the square hole of the crank it will never tighten up right again.  If you're handy with tools you might be able to take some metal out of the middle of each side of the square hole, but in reality its only a delay.

Worst case is your cranks crack through while emergency-braking.

Check out your local bike co-op.  Cranks are mostly okay on scrapped donor bikes, so they should have some in spares for cheap.

Maybe some of the information in this link is helpful.
http://www.bikeforums.net/singlespeed-fixed-gear/690261-fixie-my-pedal-crank-keeps-getting-loose.html


How to position a bike for work without a stand I want to tweak my gears, from time to time: Adjust my front and rear derailleur limits, see if the shifts are smooth, make small adjustments on the cable tension, and so on.

Is there any way to get the bike in position without help of anyone?

I don't want to spend money on a bike stand.

In my experience, most light work can be done with the bike stored upside down (standing on the handlebars and seat). Of course, I'm assuming that you're talking about a road bike. Other bikes, like a mountainbike with a twist-shifters or trigger-shifting, might not be as well suited.

Normal workbenches have these big clamp tools (a vice) attached to the edge of the bench. LINK TO IMG

You can turn your bicycle upside down and carefully clamp the top tube. I use rags to protect the frame. The bicycle is as stable as it can get.

EDIT* This method should only be used on steel frames and with great care. Also keep in mind that high quality steel frames are 'butted' (thinner in the middle).