Safe and proper (or vice versa) left turn in traffic I'm new to commuting in traffic, and I realized immediately that the left turn (US traffic rules, right turn in UK) in an intersection with a traffic light is just dangerous.  My basic questions are:

Do I pretend I'm a car and get in line behind the last car waiting?
Pros: I'm forcing people to think of cyclist 'as another car' which is half the battle as far as I'm concerned.
Cons: I don't like sprinting against cars once green if the line is long.
Cozy up next to the first car in line waiting for the light?

The proper and safest option is to 'claim' the lane and act as if you were a car by sitting in the turning lane. This ensures that you are visible to motorists and if you follow the road rules you are more likely to gain respect of those around you.

In a number of countries there are cyclist boxes in controlled intersections which offer even more security when sitting in front of traffic. In these instances you move to the front of the traffic during the red light phase.

There are some motorists who dislike this however and you need to be watchful (and mindful) of irrational drivers who may take offence.

Another option is the "Hook Turn",  under other names in different places. It is legal for cyclists in many places, but not all. I personally consider a far safer option then crossing lanes of heavy traffic and riding in the left hand lanes.

Essentially you remain in the right lane (US) and stop in front of the cars waiting to go across the intersection (in the direction you want to go). As soon as the lights turn green, you move off.


How do I revive my front shock? I left my mountain bike hanging from the front tire for a long time. Now my front shock is seized. What should I do to fix the shock? I'm considering spraying it with WD-40, but I'm not sure if that will further damage the shock.

I can attach a picture of my shock if that would be helpful. The shock is close to 20 years old too if that matters.

Manitou mach 5 sx answer cartridge shocks

Depending on the age, personal attachment, and value of the fork, you could have it rebuilt at you local bike shop. However with it being close to 20 years old you might be just as well suited to purchase an inexpensive replacement fork.

You should be able to get something like a Suntour for a relatively inexpensive amount. You might check your local classifieds for a used fork as well to save some money. Weigh how often you use (or plan to use) the bike against how much money it would cost to replace/rebuild and decide if it fits your budget. No need to pay $100 to hang it back on the ceiling for another 20 years :)

just rag the bike take it over a big bump or hit a pothole a few times and your bike should be ready


Rear derailleur on this set I have one KHS sixfifty 500, I want to upgrade my bike so I have already bought

Shimano Deore XT M771 front derailleur
Shimano Deore M590 shifter

So I want to know your suggestion to rear derailleur and cassette?

I want to know if exist rear derailleur with lock.

I was planing to buy Shimano Deore XT M772 rear derailleur but its hard to find in Brazil, so has a model like this?

Thanks

Indeed as per the comments the 'lock' mechanism on Shimano rear derailleurs (to reduce chain slap) is called "Shadow Plus". Whilst this was initially a feature of the higher end models (XT / XTR) a few years ago, it has since filtered down to some lower models, such as SLX and Zee (although I think not yet on Deore ... anyone correct me?!)

Since seems you got a 9 speed shifter, you are going to need a 9 speed cassette, like the Shimano HG80 SLX 9 Speed Cassette.

As for deraileurs, you can use the Shimano RD-M615, which is marketed as 10 speed, but it will work with your setup with no problem (I used an Alivio RD which is 9 speed on a 7 speed bike for a long time, it gave me very nice shifting and reduced chain slap on that bike, which I used to go to work.) What is important to match is the shifter and the cassette, they must be of the same speed.

As for RDs, you can use practically any shadow plus RD you can get your hands on as long as its medium or even long cage. Because you are on 9 speed, the medium cage is enough for you, will give you a lighter RD with better ground clearance, but a long cage one will do the job too.

The ones you cannot use are the Zee and Saint RDs, because they are short cage model, so if you are going for double or triple rings in front, they cannot take up enough chain links for the front shifts.


What is the widest tire for the 27.5+ width rims? Assuming that there's a line between fat wheels and plus sized wheels (which I am not sure of), then, where would this line be?

I read that a 3.5" tire is considered a "plus" one. Like http://plusbikes.com/first-look-panaracer-fat-b-nimble-27-plus-tires/

A 4" wheel, as far as I know, is a "fat" one.

Where's the border? Is there one? Does this have sense?

I'll venture a guess that currently there are two lines defining the "plus" range you are talking about.  Anything under 2.75 to 3 inches will likely be defined as a regular MTB tire.  These were often called "fat tires" until Surly popularized the Endomorph, which made the term "fat tire" fall out of favor for regular mountain bike tires.

The original Endomorph was (I believe) a 3.7 inch tire which sort of starts the current range of "fat tires" and goes up.  "Plus" tires are a relatively recent thing that Surly also had a big hand in (look up the Krampus or the Knard) that consists of tires to big to fit the frames of most regular mountain bikes, but still a bit smaller than the current "fat tire" market (3.7 inches and up).  I'd say the current "Plus" range is maybe 2.7 inches to 3.7 inches.

One of the current uses for the plus set that I have seen is running 29'r plus tires and wheels in a 26 inch "fat bike" frame for summer or hard trail conditions.

Again all of these definitions may change as the market and common tire sizes change, but I believe that's about the current state of things.  When looking at these setups perhaps the most important thing to consider is what size the frame will be required to fit the setup.

The wheel diameter has no bearing on the tyre width.

Numbers like 26", 27.5", 29" are related to the wheel diameter - how far it rolls per revolution. Numbers like 1.5",4" are the tyre width. Not all tyre widths are compatible with all wheel rims or all frames, so you need to look at the rim width and frame clearance.


Bike Hydraulic Brakes constantly pressing against the rotor I hope you can help me with this issue. My bike has Avid juicy 7 brakes, and lately both the front and the rear brakes are pressing against the rotor, which makes it really hard to ride it (feels like putting more resistance on a stationary bike). In the past before it got to this point the brakes randomly would be looser and then later more firm.
Is it a bleeding issue or do you think that it's something else?

I would appreciate any suggestions. Thanks in advance!

There are a number of things this could be.  Your rotors could be bent, your wheels could be improperly placed in the dropouts, your pads could be failing to contract, your brake calipers could be improperly adjusted, or your pad engagement point adjustment knobs could be failed or improperly adjusted.

It's likely not a bleed issue (brakes that need to be bled are generally "soft) unless someone injected enough fluid in your brakes to make them permanently partially contracted.

Your best bet is probably a trip to your LBS to get it sorted out.  You could also try the assembly steps here (for your brakes) or find a resource that explains how to adjust hydraulic disc brakes.

Sram brakes always feels on and off, so there is nothing much you can do about it. Many of the sram users have reported that their brakes feels firm at one moment and the next moment, the brakes feels weak (no power).

Anyway, I am not sure if sram and shimano have the same piston set up/design. On the shimano brakes when my pads are rubbing against the rotor, I disassemble the piston and use something to push the pads back in. This allow more space for the rotor to move about.

Also, remember to check if your rotor is straight. I dont think bleeding has any effect with the problem you are facing.


Shimano Revoshift twist grip unusably tight Shimano twist grip shifter on Apollo Neo 6 girls bike. I bought this bike 6 months ago for my 7 year old.

After getting it serviced at 99 Bikes the shifter was so stiff my daughter couldn’t change from the 2nd gear into the first.  Took it back & the mechanic checked it & said it was normal.  I insisted on him replacing the gear cable but… no change.  I flooded the handlebar twist grip with lube but no change.  Went back to the shop and the same guy said nothing wrong and that’s how those shifters work.  I demonstrated that my daughter couldn’t access the first gear.  Seriously, it requires a very firm grip and a firm twist even for an adult.  Now I’m quoted $100 to replace the shifter with a thumb shifter.  My daughter is normal strong for a kid.  Is this a design fault or a mechanic needing replacement?

As per AndyP’s comment, I have also heard anecdotally that these styles of shifters can be stiff for children’s hands, but then again some thumb push trigger shifters can feel quite stiff to my adult thumbs.

As you mention it is most difficult for your daughter to access first gear, I would investigate or have the shop check the Lower Limit screw on the derailleur. If this is set a fraction too tight then the shifter is trying to pull tension against this limit. If this screw is set too tight then the shop should adjust it to the correct position as part of the labour you’ve already paid for. It’s probably only a fraction of a turn.

Otherwise, changing to a trigger shifter unit needn’t be very expensive, but I would try models out and find which suits your daughter’s hand strength the best. if you’re quoting AUD price then maybe it includes the part cost and a minimum labour charge and that’s how much it costs to have work done on bikes where you are.

It has been suggested by an anonymous edit, from a person who had a similar problem, to double check the cable placement at the derailleur fixing bolt. For example this extract from the Shimano Tourney Dealer's manual

I would contact Shimano. I've used Shimano for decades and this problem surprises me. Shoddy assembly and incompetent, uneducated, service personnel can derail the best of equipment.
My usual approach is to obtain the mailing address of the Corporate Office, and the name of the CEO. This has always resulted in the outcome I want. This should be an excellent bike, not the high end IBOC MONGOOSE of the 80's and early 90's but still a cut above comparably priced bikes.


How to fix a detached brake cable? My rear brake cable detached yesterday while riding. When I pull the level all the way back (which I can now do with no tension), I think I can see the end of the brake cable inside the brake hood, but it's no longer being pulled by the lever.

2 Questions:

Is this a common problem? It seems like the cable shouldn't detach easily, but if something is wrong either equipment or technique-wise I'd like to correct it post haste
Is there a way I can re-attach the cable without disassembling and re-taping my handlebars? (My bike has standard road drop bars)

Without pictures or a better description, it's hard to know if it was a failure of the cable or the brake lever. If the brake lever has broken and can no longer grasp on to the end of the cable, you'll need to replace the lever itself. However, a more likely scenario is that either the nub on the end of the cable that the lever holds on to has come off. You may also have a lever where the nub can pop off of if there's no tension in the cable, which can happen if there's too much friction in the cable housings. This may also be caused by the cable having become detached from the brake: you're pulling the lever, but it's not attached to anything.

The quickest and easiest thing to do is try to simply re-cable the bike. This can be done quickly (time: 15m) and cheaply (cost: $10), and in doing so will also help diagnose if the problem is deeper. You should also go ahead and re-cable the other brake lever and the shifters as well — if this was caused by a failure in the cable, the other cables may be ready to fail as well.

To get the cable out of the brake lever, pull the brake lever until you can see the cable, or where it should be. Find where the cable comes out of the other end of the housing and push it through until it comes out through the handle. To replace it, just thread the new cable back through and clamp it on the brake. It should look like this:

If you feel a lot of friction pulling the cable out or installing the new one, you should replace the housings. This will take a little bit more time (45m) and some more money (housings: $10, bar tape: $15), but is still pretty easy to do. Unwrap your handlebars and re-insert the brake cable, replacing the old housings as you go. Wrap the handlebars back up, and you should be all set.

If the nub end of the brake cable isn't being gripped by the brake lever, or the piece to do so is missing, you will have to reinstall a new brake lever. This will be a good bit more expensive, and will also require that you re-wrap the handlebar tape.

Best of luck!

Go to this site: http://www.zinncycles.com/book_and_dvd.php and get the book appropriate to your bike. You most likely need: Zinn and the Art of Road Bike Maintenance.
You can also check out Park Tool. http://www.parktool.com/ Many techniques/methods are available here.

And, FWIW, I have few issues with putting my greasy hands onto the $24 Zinn book; however, greasy hands on the MacBook (or your laptop of choice)....not so happy about that.


Is it possible to replace a 1 1/8 steering tube with a 1"? I have a 94 Giant ATX. Threaded 1 inch steeering tube.

I need a shorter stem, and would also like to install a suspension fork.

Is it doable? Could I take a modern suspension fork, heat the crown, smash the steering tube out, install a 1" tube (with some added metal so that the outer diameter is 1" 1/8) the get rid of the threaded headset and install a threadless 1" headset (does it even exist?)

Bear in mind that I'm in Argentina, and it's very difficult to get parts from US shops.

I'm going to recommend that you NOT do this.

There were in the past manufacturers of 1" steerer suspension forks - though I'm not certain that they're are still sold. It is important to note that bicycle frames built to accept solid steel forks have different geometry than those built for suspension forks. The frame is designed for a fork that doesn't have suspension travel - the head tube is taller, the down tube and top tube are welded to preserve the set geometry of the bike. Installing a suspension fork would lift the front of the frame up and slacken the head tube angles - overall, I suppose it isn't a huge deal...HOWEVER...

If you're having a hard time finding bike parts, will finding a 1" steerer tube, a suspension fork that has a brazed steerer tube, a bushing that is machined to fit precisely and a machinist to make your bushing, and someone to braze this all together be any easier than finding a more modern bike frame or a used 1" suspension fork?

You might be able to remove the steerer from the suspension fork if it is brazed in, but retrofitting a new steerer tube will require a bushing machined to VERY precise tolerances to allow for heat expansion and brazing filler flow. Any valves, adjusters, stanchion caps...anything not brazed or welded to the fork crown will have to be removed to prevent any damage while heating. You'll want this done professionally because a failure while riding would be regrettable.

With the amount of work involved, it may be more cost effective to track down a mountain bike frame with a 1-1/8" suspension-ready head tube or just have someone replace the head tube in your existing frame.

Also, it may not be too difficult to find an affordable bicycle in Argentina. Here is the distributor for Giant bikes in Argentina. You can email them at: info@giant-bicycles.com.ar. You can locate Giant vendors by province here. If Giant is represented there, you'll likely find other companies and reputable bike shops who can order you frames, parts, bikes, you name it.

Added info:

Here is a forum thread detailing fork building. The most important point is the fit of the steerer to the crown. If it is too tight, the brazing filler won't flow evenly and consistently, too loose and the integrity of the braze is compromised. If you do decide to do this, definitely try it more than once. The first two or three you should cut up to inspect the brazing filler flow (cut lengthwise and try to pull the pieces apart. Bubbles, seams, and burnt flux are all signs of a poor joint.) There is a comment about brake bolts and wedges being used to prevent steerers from pulling out of the crown, but I wouldn't risk it.

Sure it is possible and Kits available.

http://www.instructables.com/id/Replace-a-mountain-bike-front-fork-for-older-MTBs/


How do I remove these crank bolt plugs I have an old 10-speed bike (presumably 80's vintage). I'm trying to remove the bottom bracket and cranks but have struck a problem.

The crank bolts have a plastic cap over the top of them and I'm not sure how to remove it. They look like they should unscrew based on what I could imagine it would look like before they were trashed by the previous owner. I tried to unscrew them gently but they didn't move and as you can see from the photo below they're very fragile.

On the other side the cap has been completely broken.

I can see a nut, but with the plastic cap extending into the cavity I can't get a socket in there. I need to remove the plastic somehow.

Anyone have any ideas how to remove the cap and it's remnants?

Normally, the cap just unscrews. Obviously, that's not the case here. Use something like the tip of a knife, a small screwdriver or a chisel to break it up and pry it out. But try not to mess up the threads too bad, you'll need them for the next step.

I think what you have is a square-taper crank design; the bottom bracket spindle has a square-shaped tip, the crank is wedged onto that tip and secured in place with the nut. Once the nut is off, you'll need a crank puller. It's a cheap tool, you can get one at any bike shop. The puller has a sleeve that threads into the crank (into the same threads that the cap attaches to); then you screw down a bolt inside the sleeve that pushes against the spindle, and hopefully pops the crank off. This looks like an old bike, so it might be stuck on there pretty good.

When reassembling, just put the crank back on and tighten the nut. Make sure you put plenty of grease on the mating surfaces.

Yes. Pop the plastic off with a screwdriver, a lil wd40 won't hurt. Just remember, CRANK ARMS SCREW ON BACKWARDS! left tight,,, right loose,,, also. It may be a european bottom bracket.


What should I look for when buying chain lube / lubricant? In the past, I personally have only used WD-40.

However, I have occasionally had my bicycle looked over at the locally run, free service sessions and most of the mechanics there use a hand applied type of greasy gel (I forget the name).

Questions:

Is WD-40 suitable for bicycle chains?
Would alternatives provide better chain longevity?
When shopping around for lubricant, what are the most important things to look for?
What do you use and why?

(optional added extra) Any tips for reducing chain wear?

This question leads to one of the great religious debates of the bicycle culture. Ask ten mechanics which chain lube is best, you'll get ten different answers. The honest answer is "it depends on your maintenance habits and the weather and your preferences, so you should try some different things until you develop an opinion of your own." That's tough to do without understanding what to look for.

The main species of chain lubricants you will see:

Oils of various viscosities. Often sold as 'wet weather' lube. Finish Line wet is an example.
Teflon in an evaporating solvent. Often sold as 'dry weather' lube. Finish Line dry is an example.
Wax in an evaporating solvent. White Lightning Clean Ride is an example.

Oil is a fine lubricant. It sticks on your chain fairly tenaciously in bad weather, so requires less frequent application. On the other hand, road dirt can accumulate quickly and turn into a nasty black paste, especially if overapplied. Wipe extra lube off the exterior of your chain after application!

The Teflon and Wax style lubricants have a lubricating substance in a solvent. The solvent lets the stuff flow, distributing the lubrication to the inner crevices of your chain, and then evaporates, leaving the lubrication where it needs to be. Then, like with oil, you wipe off the exterior of the chain. These chain lubes tend to leave your chain less messy, but can wash out more easily in rainy-day riding.

Take those considerations into account and pick whichever seems most suited to your situation.

As other answers have mentioned:

WD-40 does not make a great chain lube, what lubrication it leaves after evaporating is too thin.
Do clean your chain, externally with a rag at the very least, before re-lubing. If you do a thorough clean with solvent or degreaser & water, make sure your chain is completely dry before reapplying.

Your points:

Is WD-40 suitable for bicycle chains?
Yes. It may not be as good as dedicated products in this or some other aspect but it is tested by many and it DOES work.

Would alternatives provide
better chain longevity?
Probably. Dedicated products will likely work better in the conditions they were designed for. Dry lubes in dry conditions, wet lubes in wet conditions. There are many products available, some will be better, some will be worse.

When shopping around for lubricant, what are
the most important things to look for?
Dry vs. wet lubes. This is by FAR the most important distinction.

What do you use and why?
Polls are off topic. I will not mention dedicated products but I mostly use certain ceramic-based dry lubes. Dust is by far my biggest enemy in these very dry years and I need my chain to attract as little dust as possible. At the current time I temporarily switched to the cheapest mineral oil they had since my favourite product wasn't available. It also lubes well, maybe even better, but the chain is significantly more ugly and attracts grime more.

Your specific question about WD-40:
This is hugely unpopular at this site and will surely be downvoted into oblivion, but many people report success when using WD-40, the classical one, as the only chain lube and a degreaser at the same time. The most public of them likely being Simon Richardson, a former professional racer (also a cyclocross racer) and now a presenter of GCN - the Global Cycling Network. For example, but not only, here

Also, while WD does really stand for "water displacement" it is actually a lubricant at the same time. The vendor's page says:

Myth: WD-40® Multi-Use Product is not really a lubricant.
Fact: While the “W-D” in WD-40® stands for Water Displacement, WD-40®
Multi-Use Product is a unique, special blend of lubricants. The
product’s formulation also contains anti-corrosion agents and
ingredients for penetration, water displacement and soil removal.

I used to use it too, but now I mostly use other lubes, ceramic ones or other dry ones. My last encounter with a wet one (green Finish Line) was very unpleasant because although it was somewhat wet outside, it did not straight-out rain and it left my chain in a horrible mess, noisy in an unusual way, and was very hard to get off even using a chain washing tool. Think twice before using when it is not straight-out raining. Perhaps a small bottle of a thin oil with you in case of a rainshower would be better. Even re-lubing mid-ride might be better (for long rides, especially multi-day ones).


Multi-city bike rental in Europe (NL, BE) I'm considering a bike trip in Europe, primarily the Netherlands, over a week or two. But I'd rather rent a bike (in fact, two) than bring mine all the way from Australia.

Are there any options for 'one way' bike rentals, so that I would hire a bike (a relatively decent multi-speed one, kitted for touring), say, in Amstrerdam and drop it off a week later in Brussels? While normal for car rentals, I haven't heard of such options for bikes...

I didn't think this was possible, but Google came up with this site (in Dutch) https://www.fietsverhuur.nl

Apparently they deliver rental bikes in Belgium, The Netherlands, Germany and Luxemburg. I assume they can also arrange a pickup at a different location, if the price is right .

It isn't clear if this is just for groups, but you could contact them if you want.

There are public rental bikes available in many major European cities Amsterdam and Brussels among them, but these are mainly locally based and meant to be used locally and not to travel between places. Most are operated via a membership system, long-term, short-term or daily, that is only valid on the local territory. The idea is that you use the bike to travel between stations, put it back in a stand and release another one when you move on.

But I think that you may find bike-shops where you can hire a bike for a longer period, although you'd most certainly have to return them to the same place.

Ad-on: Check youth-hostel websites. Some may be linked to reconditioned, second hand or rental bike schemes.


If I mount a standard (tube needed) tire on a tubeless compatible rim will it be easier to remove when I get a flat? I'm running a tube in my tubeless compatible WTB rim and WTB Byway tire and am finding it nearly impossible to break the seal when I've gotten flats.  If I get standard (non- tubeless compatible?) tires, will make it easier to change flats?  Any advice appreciated.

The difficulty rating varies by tire and rim and which combinations are used. Some tires may come off easier on some wheels and be more difficult on others. In general tubeless rims make it more difficult to break the bead loose. The reason is that tubeless rims have an extra bump next to the spoke holes. The purpose of which is to keep the tire from unseating in the event of a flat. You may want to try putting the tires on and off a few times to find a technique that works best. I recently bought a Crank Brothers Speedier Tire Lever which is different from the standard levers. The rims I have used it on weren't tubeless but it did seem easier to get the tire off.

No.
I recently bought an e-road-bike. It had two 28-spoke wheels with straight gauge 2mm spokes, rims without eyelets and no-name hubs that don't have cup and cone bearings. The rims are tubeless compatible. The stock setup had inner tubes, though.
Then I wanted to put some GP5000 28mm non-tubeless tires on the rims. Removing the old tires and putting in new tires was a major chore. I estimate I had to fight about 30-40 minutes per wheel and in the process I punctured one inner tube with tire levers and had to replace that tube.
A bit later, the front wheel lost all spoke tension. I presume it was due to having only 28 spokes, not strong enough, and was probably made worse by the spokes being straight gauge.
The bike shop that sold the bike had a clever "solution": put thread glue into the nipples and tension each spoke to a varying not-so-high tension.
Needless to say, my final solution was that I hand built a new wheelset. I specifically chose non tubeless compatible rims having double eyelets and 36 spoke holes, cup and cone bearing hubs and 2.34mm/1.8mm/2.0mm triple butted spokes.
I can repeatedly install the very same tire on the new wheelset, without using any tire levers, in far less than 5 minutes, without ever puncturing the inner tube in the process.
So, most likely you'll need to get rid of the awful tubeless compatible rims and put some non tubeless compatible rims there. The easiest and best way to get a non tubeless compatible rim is to select one having double eyelets -- those are not compatible with tubeless setups. The double eyelet rims are stronger and far less likely to crack around the spoke holes as a bonus.


Attaching LED strips to bike I'm interested in attaching LED strip(s) onto the frame of my bike. Are there features of LED strips that I should be looking for when making my decision of which one to get? What's the best way to attach them?

I plan to use the lights only from time to time, and would not mind having them battery powered (I would use rechargeable batteries anyways). In terms of colors, I would love to have the strip able to oscillate in patterns (most do in any case), though this is not necessary.

Sense this topic has re-opened i will submit an answer.

For custom frame lighting i believe it would be easiest to adapt a product that is already intended for use on bicycle frames or wheels such as what it seen below. It is a weather proof battery box wired to a silicone tube filled with chip LEDs, basically a rope light, the idea is the battery box attached to the hub, and the rope portion is woven through the spoke and centrifugal force with a little help from zip ties keeps it in place.

They come in a variety of colors from a variety of manufacturers. Thus is why i think this would be the most simple and cost effective form to adapt. You could simple attach the battery box beneath the stem or any area out of the way and zip tie the rope where ever you want it on the frame. you could combine colors and get creative with it quite easily.

I know that the US distributor J&B sells them so most bike shops in the US should be able to get them, and ive seen them other places on the net as well. Their rather popular for customizing cruisers.

Heres a couple images of them installed:

I would argue for self-adhesive LEDS because they might have a more refined appearance, especially at day time. I would minimize the cable-ties and other fasteners for a cleaner look. Clean the bike well before adhering your fancy lights!


Minimize freezing of brake cables Is there something I can spray on my brake cables to keep them from freezing up in cold weather?

I want something preferably that will not attract dust.

Brakes froze when temperature was 20 degrees F.

They are likely freezing because water is getting into the space between cable outer (cable housing) and the cable inner (the wire brake cable). Water expands as it freezes, in doing so it takes up more space than is available in an otherwise the restricted system.  Because the cable housing is relatively inflexible to expansion (it needs to be otherwise your brakes would be mushy) this ends up binding the inner brake cable causing your brakes to metaphorically and literally freeze.

About the only way to fix the freezing is to prevent water from getting into that space.  Adding oil or grease will likely not be enough to displace all the water, and as the remaining water expands when turning into ice you are left with the same problem.

As a quick fix you can bring your bike into someplace above freezing and hang it so that the water can drain out of the cable housing.

A more permanent fix depends on whether or not you can fully seal the system against water ingress. This depends on the type of brakes you have and how the brake cable is routed. I have only ever experienced freezing of brakes in sub-zero conditions on a bikes that were using full length brake housing, with the rear mechanical disc brake was mounted on the lower chain stay with no real seal between the brake housing and the disc caliper.  Rain water would slowly drip into the cable housing from the open end at the caliper and pool somewhere mid-chain stay.  Then when the weather dropped below freezing the rear brake would freeze solid.

The only to prevent this is to have some sort of seal that prevents water ingress into the housing from happening (e.g., see below)

If you have another type of brake system or a different cable routing from what is pictured above I would need to see a picture to try and diagnose how water is entering and remaining in your brake housing.

UPDATE

From your picture your cable boot on the rear brake appears to be dislodged. This will allow water to enter the system, where it will pool in the cable housing just after the brake noodle (see figure below).

I had the same problem, and poured a pipet of antifreeze into the brake lines with great results.  I had to do the same with my bike lock which also froze.


How do I keep my pants/trousers from getting caught in the gears? I have the unfortunate habit of always getting my jeans stuck in my gears and end up with a nice rip on the seams.

I've used those velcro braces to keep the bottom of my pants leg close to my body but I guess I pedal too close to the gears as those get caught in the gears too.

There are basically four solutions that do not involve extensive work on your bike:

Roll up the pant-leg on the gear-side high enough to stay away from the gears.
Wear tight fitting cycling pants that don't flap.
Use braces as you have, or clips such as these to keep your flappy pants close enough to your legs.
Stuff the pant-leg on the gear side in your socks.

Since option 3 doesn't work for you that leaves you with options 1, 2 or 4. However, when applying the braces or clips, (or stuffing your pant-leg in your socks) are you taking care to make sure all the excess pant-leg material is collected on the outside of your leg, away from the gears?

On the bicycle side: Chainring guards might help a bit, even better is a full chainguard but these may be hard to find for your bike.

What I do is just get some electrical or duct tape and wrap it tightly around my ankle.


touring bicycle with roadster frame I am from India and am planning to get a new bicycle. In India the roadster bicycles are very common, hence are cheap and easy to get. Roadsters have 28.5'' diameter wheels. Is it possible to fit 700c wheels to roadster frame, install drops and new drivetrain (and brakes) to make it perform like a tourer?

I'm not sure of the exact size of your rims, as it doesn't appear that a 28.5 inch tire is mentioned anywhere in Sheldon Brown's rim sizing chart. However, there is mention of a 28 inch wheel which is used on "Indian Rod-brake roadsters". The actual measurement for this rim is 635 mm. 700c wheels have a 622mm BSD.  This means that 700c road bike tires are smaller (assuming your bike has 700b tires mentioned on Sheldon's site).  Which means you may be able to fit the 700c rims on your bike, provided your brakes have enough reach.  Check the rim size by reading the numbers off the tires. There should be a number there like 635 or 700b if they do use the 28" tires.

As to the question installing drops and a new drive train and brakes, that might present other problems. If this is the type of roadster you are referring to, there's a couple things you'll have to look out for. Dropbars could be easily installed, but there's a lot of other stuff to consider. Is the rear hub spacing the right size to accommodate a wheel with a standard road cogset.  Are there proper mounts for caliper brakes.  The bike in the provided link has "rod brakes" that use rods instead of cables.  Can the bottom bracket be replaced with one that is compatible with a crankset you like.  It might just be easier to keep your eye out for a used road bike rather than try to convert a roadster into a road bike.  You'll have to buy quite a few new parts, and often the price of the parts far exceeds the price of a bike.

It's hard for us to speak with any certainty about your particular bike that's halfway around the earth. However, it doesn't sound like you'll be able to do it, 700c wheels are 29" in diameter and your wheels are 28.5" in diameter, so they may or may not be half an inch too big.


Can I use normal grease for a car on the surface of carbon bike? Helo Guys,

I want to know your experience about carbon material and grease
Can I use normal grease with carbon ?
I want to put grease onto fork and stem....

Or WD-40 or silicone penetrant would be ok ?
Thank you....

Can I use this one ?

From Sheldon Brown:

Grease lubrication is commonly used on all ball bearings. Good mechanics also use grease (or oil) on the threads of most threaded fittings and fasteners, and also inside the steerer (to keep the stem from becoming stuck) and the seat tube (to keep the seatpost from becoming stuck.)
There are a great many different greases on the market with different special features, mainly for automotive applications. For bicycle use, almost any grease is adequate, since the loads and temperatures are generally low.

Seems to me like the answer is yes, although to be safe why don't you invest in some Finish Line Teflon Grease - one tube will last you for years. From the Finish Line website:

Q. Are Finish Line products safe for use on Carbon Fiber Frames and Parts?
A. Yes. All of our products are safe to use on carbon fiber bike parts; our three degreasers, four lubes, our polish, grease, etc are all safe to use on and around carbon fiber bike parts. The exception is our DOT Brake Fluid – you don’t want to get DOT fluid on any painted or finished surface because it’ll attack the paint / finish.

i would be careful of any type of grease i use on a bike.. Grease attracts the dirt and can lead to further issues on the mechanics of your bike. like stated before - use an oil specially formulated for your bike. and make sure after every cycle to clean your bike down and re-oil.


Road bike carbon fiber frame life span I have read in several places that the carbon fiber has a shorter life span than the aluminium, and i was wondering just what would it be.
I am not referring to accident related failures of the frame. I would like to know how much would a frame hold for a road bike if i didn't have any accidents and road it almost daily for lets say 10 miles.

I read somewhere ( sorry cant find the link ) that carbon fiber frames will tend to crack after 4-5 years.

Absent some kind of abuse or extraordinary stress (like falling on top of the bike while it's lying on the ground - stressing the tubes from the side, riding with a friend sitting on the top tube...) a carbon fiber frame should outlast the rider.

Lennard Zinn covered durability of Carbon Forks for Velo News a while back.  Here are some quotes from that article in case the link breaks:

From Kestrel

  For carbon forks in
  general, there should not be any
  limited life span, as carbon
  composites themselves are not subject
  to fatigue failures as metals are. So
  the fatigue life of a properly made
  carbon composite is 'infinite'.

From Look

  There is no limitation because carbon
  has a natural flexibility. It can be
  used a hundred years while maintaining
  the same stiffness.

From Easton

  The good news is the fatigue life of
  carbon fiber is immensely more than
  that of metals. While the writer
  expresses concern about his carbon
  fork lasting as long as a metal
  component, there is nothing to worry
  about in terms of fatigue life on a
  composite fork.

Having ridden since the early 80's I've been through this twice, once with aluminum frames and now with carbon fiber. As high end competition bikes were made of the materials there were questions of durability.  Over time, as the frames became widely available, those concerns were shown to be largely baseless.

I believe most frame builders warranty carbon frames for life now. I personally know of at least two riders with carbon fiber bikes that have been ridden in excess of 100,000 miles.

That said, you should periodically inspect the frame for cracks and wear, especially at stress points like around the bottom bracket (just like you would with any frame).

Carbon fiber is durable.  Unfortunately, carbon frame is not just make of pure carbon fiber, but instead it makes of carbon fiber reinforced polymer - composite carbon fiber.  The carbon fiber may withstand the test of time, but the polymer is subject to degradation.


Why dual pivot brakes, not longer brake arms? Dual pivot brakes are marketed as having "more braking power", which in technical terms means higher mechanical advantage. Exactly the same effect can be achieved by longer brake arms (ones which are pulled by the cable).
It was pointed out that dual pivot brakes are more convenient to center, which I disagree with, but that's a different question; here I'm asking about getting the same mechanical advantage without two pivots.
Is there a technical reason to use a more complicated construction? By "technical" I mean "not related to marketing". "Dual pivot" definitely sounds "cool" and probably sells well.

The single pivot sidepull design requires a fairly wide pad gap at the rim in order for centering to not be too finicky. It's essentially the widest of all common rim brake designs. This is due to the spring design's two sliding contacts, as Jobst Brandt writes about here. The contacts are hard to keep at the exact same level of friction, and any disparity takes the brake out of center. You need a wide gap to compensate, at least for a normal person not fiddling with their brakes all the time.
You can't just add longer actuation arms to make the same design more powerful because it's still the same human hand at the lever end. If you want the pads to be able to touch the rim, then longer actuation arms with the same pad gap would require either shorter lower arms, which you can't do because there's a tire there, or a lever that pulls more cable. You can make the lever pull more cable, as in a v-brake lever, but note that v-brakes have a much smaller pad gap. That's why they can have a lever that generates much less mechanical advantage. Do the same thing with a hypothetical long-armed single pivot and you get a brake with very low power.
In other words, all brake designs are bottlenecked by the input force. You can't then have one that's also bottlenecked by pad gap and have it compete on power with ones that aren't.
What amount of pad gap should be designed in to the brake to overcome the centering issues is subject to both opinion and potential design advancement. You may even disagree with the premise that this is a design limitation, and that's fine; every real advancement in component design does. If you made a single pivot brake that could happily run with the pad gap of a dual pivot, then yes you could increase the arm length to get the mechanical advantage of a dual pivot. There's presumably some way of doing it with graphene.

Dual-pivot brakes move the pad to the rim quickly, with low mechanical advantage (pivoting around pivot 1), and then switch to pressing the pad against the rim more slowly, with high mechanical advantage (pivoting around pivot 2). This gives you the best of both worlds.


Is it safe to attach a flashlight to a helmet? Everything I've found online discussing this has focused on the benefits and dangers of attaching a metal mount to the helmet, on which a flashlight would be attached.

I'm using a soft mount (specifically paracord), and I was unsure if the flashlight itself presented a hazard in a crash.

Here is a shot of the flashlight and how it's attached:

Front view, showing placement. It's offset so it's aimed a bit better at were I'm looking.

All of the mounts from reputable manufacturers thatI’ve looked at are either rubber or Velcro or have a quick release that’s designed to tear free on impact.

Paracord is incredibly strong - some have a tensile strength of over 200 kg /550 pounds.

The concern is that your head might hit an object (such as a low tree branch) and the light or mount will snag on it, whipping your head and neck back. The neck vertebrae don’t like this motion.

Also, in an accident the helmet is designed to slide along the ground preventing torque to the head. Your paracord might also snag and cause the helmet to torque your head.

Note it would take a freak accident for this type of injury to occur. An individual might be fine with accepting this type of risk personally. A manufacturer who has domestic assets that could get seized in a lawsuit might not be willing to accept the risk, thus they err on the side of caution. On this forum, we can’t say “it’s fine” — that’d be negligent but we could say that many people would find the risk acceptable but ultimately it’s your call.

Tl;dr: ideally, you’d want your mount to have a full break-away design.

There are many helmet mounted lights available in the market. Yes, as @Paparazzi mentioned, this should be fine. I personally find this makes the helmet slightly heavy and prefer handlebar lights.


Any fix for a schrader valve that won't open? I have the all too familiar problem of being unable to pump up my tyre :(

It's not a problem with the pump (because it works on the other wheel) so I guess there must be something wrong with the schrader valve. I've done all wiggly woggly poking efforts to get it to release air, tightening, untightening the pump head etc. to no avail (I just keep pressurising the pump instead of the tyre). However the valve doesn't "look" damaged (the pin is in place, straight, not obviously damaged).

Is there any other possible fix to this that I haven't tried? Some clever tip or trick? Or should I just give it up and buy a new inner tyre?

Sounds like the valve has stuck shut, this can happen if the rubber seal at the base of the valve swells up. If the valve core is replaceable just get the appropriate valve tool and a replacement core,  both are really cheap.

Otherwise its likely to require a replacement tube.

I have the same problem with Schrader valves. I have replaced the core. The valve still will not let air out, and has a lot of resistance letting air in. The pin in the new Schrader valve is mobile when screwed into the valve stem. The actual air seal in the valve STEM must be stuck somehow. A bit of air did go in, but what an effort it was. Very very stiff. Now the tire is round, sausage shaped, not flat anymore. I've sprayed   lubricant into the valve, put the core back three times, pumped the pin up and down, up and down... whatever is inside will not come loose. I know I can just get a new inner tube, but I'm still frustrated. The bicycle stood for 18 months till I found time to fix it.


loose spoke that will not screw back in Noticed that my rear wheel is pretty un-true and is hitting the brake pad / wont spin freely.

Decided that I would try to fix it myself before opting to pay 20 bucks.

There is one spoke that is completely loose. The problem is that one i turn the spoke it does not tighten, nor does it feel like its being screwed into anything.
(my spoke is straight all the way - i have this wheel)

Questions:
1. Can I fix this, or do I need a new spoke / bike mechanic
2. Does riding like this make things worse (aside for greater wear on my brake pads)

The spoke and nipple are turning together? This wheel uses straight spokes. Don't think it's likely, but the notch could be stripped at the hub, meaning there wouldn't be anything you could do about it besides get a new hub.

I think more likely your spoke nipple is probably stripped. Try to get another one from somewhere that is the same size as the ones already in your wheel, and try to replace the bad one. You just need to take off your tire and rim tape, and pull the bad nipple all the way out. Then get another nipple (2.0mm diameter) and thread on. See if it works. Could also be bad threads on your spoke.

If you can turn the spoke, the spoke must be broken; or, if it's a straight pull, try to tighten it at the hub.


Why aren't electric bikes mainstream? I've lived in different cities in Europe and Australia, and I noticed more and more the creation of bike lanes, and increases in bike commuters. Still, the number of eletric bikes in the streets is incredibly low. Although it can be said they are expensive (see related question), I cannot believe this is the only reason.

So I ask the experts: what is the biggest issue to bring them to the mainstream market?

I would add to the already existing answers some of the thoughts that come to me as a bike user.

For me using a bicycle is a mean to prevent getting out of shape. Using an electrical bike would be like going hiking with a car or elevator. This applies for a lot of my friends riding bikes.

Some of my colleagues complimented me on the fact that I exercise daily by riding to work. In the same register, I expect the opposite reaction for riding an electrical bike, as it would point the user out as a lazy/weak person, unwilling/unable to do any effort. Not saying it's true or right to be judged, but people often live by what others think about them (the coolness factor). you may get coolness points in the gadget section, but it's a different group of people that will compliment you on that. So it depends on where you want to position yourself.

A cheap bicycle is something you can easily toss in some corner when reaching a destination (edit: and of course diligently chain it up), without too much worry regarding theft. Can't do the same (with peace of mind) with an electrical bike.

Depending on where you live, using a cheap (second-hand, maybe) bicycle for two to three months already pays for the bike itself, by saving on transport costs. With an electrical bike, there is a steep initial investment, and the ROI is spread over a much longer term.

Electrical bikes are heavy and not so easy to maneuver in tight spaces where you need to carry them (like stairs). If they are light usually they are very expensive.

Finally there is the same concern as for electrical cars: will the charge last for the whole trip? If not, you'll have to pedal-drive a lot of additional mass accounting for the motor and battery.

I think the main drawbacks are weight and autonomy of the battery.


Do good tires lessen the chances of your innertube bursting? I have only bought my bike for a month and a half and within this time span, my innertube actually burst 4 times. The bike itself is relatively cheap so I doubt that the tires are of good quality.
I am currently considering changing my tires to better ones so as to not waste money on tubes anymore, but do tires really lessen the chances of my innertubes bursting/puncturing?

Its extremely unlikely for an inner tube to just burst.

It sounds like you are suffering from punctures.
There are two types of puncture; the first is an object penetrating the tire and inner tube, and the second is a 'pinch' puncture where an impact causes the inner tube to be pinched between the tire and rim.

Many bikes (even expensive ones) come with poor quality tires as standard, and yes, changing them can make a big difference to penetration punctures.
No tire is 100% puncture proof, but something like a Schwalbe Marathon Plus is very close, but is heavy and can give a harsh ride.
Continental Gatorskins are favored by many as a good compromise between puncture resistance, rolling speed and comfort.

Pinch punctures are usually caused by hitting an object (such as a pothole) with too little pressure in the tire.  Adding more air to the tire (don't go over the maximum limit) usually prevents these.

By the term bursting "Inner tube bursting" is not caused by the tire but is caused by over inflating.

Please get a good quality rubber tube(rubber doesn't change its color when tube is inflated )

Yeah and also a combination of a good tube and tires significantly reduces the risk of flats(especially on a road bike) -I have got a set of tire liners and an extra layer of rim tapes as a precaution and until date it seems to be going great!! :)


How much does tire pressure affect the weight of the wheels Kind of inspired by this question, but something I've been thinking about for a while.

How much does the air in a bike tire weigh?  Is it an appreciable amount? Is there a point where using a wider tire, like at 28c at 80 psi would be lighter than a 25c tire at 100psi? Obviously, this depends on the specific tires used.  I don't have a scale precise enough to measure, and I don't have the math/physics knowledge to figure this out.

The ideal gas law (which is a good approximation in this case) says PV=nRT where P is pressure, V is volume, n is mols of gas, R is the ideal gas law constant, and T is temperature in Kelvin.

Thus, solving for n, we see n = (PV)/(RT). Then, assuming air is made up of {gas1, gas2,...} with fractions {p1,p2,...} (so p1+p2+...=1) and corresponding molar masses {m1,m2,...}, the mass of air in a tire is (PV/(RT))(p1*m1+p2*m2+...). So, what we see is that the mass of air in a tire is directly proportional to the volume of the tire and directly proportional to the pressure in the tire, and inversely proportional to the temperature of the air in the tire.

We will make the following (reasonable) assumptions: Assume the temperature is around room temperature (293 Kelvin) and the volume of the tire regardless of pressure is the same (primarily determined by the shape of the rubber, assuming not severely under/over inflated). For convenience, air is about {nitrogen, oxygen} with {p1,p2}= {0.8,0.2} and molar masses {28 g/mol,32 g/mol}. Thus, under these assumptions (V is fixed, and T is fixed), the mass of the air in tire grows linearly with pressure.

So, the mass of air in a tire of volume V and pressure P and temperature T is about (PV/RT)(0.8*28+0.2*32) grams. It may be better to write it as "P ((V/(RT)) (0.8*28+0.2*32)) grams" noting that V/(RT) is a constant for us.

Since I don't want to put the units into wolfram alpha carefully, you can put in the entry "(7 bar* 10 gallons)/(ideal gas constant*293 Kelvin)*(0.8*28+0.2*32)" and read the result off in grams (ignoring the unit it says there) to get an estimate for the weight of air in a 7 bar (~100 psi), 10 gallon volume tire as around 313 grams. Is 10 gallons reasonable? No.

Lets be crude about estimating the volume of a tube using a torus. The volume of a torus is V=(pi*r^2)(2*pi*R) where R is the major radius and r is the minor radius. Google will calculate it for you (and has a picture of what major and minor radius is).

I can't be bothered to actually go outside and measure these things, but lets be crude and use a massive tire. Say the minor radius is 2 inches, and the major radius is 15 inches (this is probably larger the size of the tire on something like a Surly Moonlander). This has a volume of about 5 gallons. If you were a nutcase and running this at 7 bar, it would be around 150 grams of air. At a more reasonable 1 bar or 2 bar, youd be at 45 or 90 grams.

What about a thin road bike tire? Lets also assume the major radius is around 15 inches, and the minor radius is around a half inch. Thats around 0.3 gallons of volume. Plugging into our formula, at 7 bar, we see that this is about 9 grams. At 10 bar, a whopping 13.5 grams.

Wait, what? The above answers comment on the mass of the air inside a tire (which I assume is what is being asked). However, what is the weight difference from an empty to an inflated tire? Buoyancy says zero!

Only measure from this point on is the change of moment of inertia of the tire i.e. how easy it is to accelerate.


Rubber on wall mounted bike hooks is wearing away. What can I use to cover them so my wheels don't get scratched? Vinyl covered wall mounted bike hooks coating is wearing away due to use. What can I use to cover them so my wheels don't get scratched?

Using These type of hooks:

@rclocher3's electrical tape is the easier way to go, but I often use strips of old tube to wrap things of this nature.  To keep the wrap in place I dab some vulcanizing fluid hither and thither along the underside.  This saves electrical tape for electrical things, is perhaps a bit more rugged than tape, and also provides fodder for people who would mock me on stackexchange.

Use Plasti dip? Or get some new hooks. They are cheap. or these? http://www.foothillproducts.com


How to protect rear derailleur while mountain biking? I am a college students, and I live right next to an amazing rocky area (picture below), I bike every day, and while I am getting much better and more confident I still take a pretty hard fall every so often.

My derailleur has been crushed so many times, and I have been forced to literally pull on it to bend it back into shape on more than one occasion.

I am hoping to replace the derailleur soon, but I would like to know if there is a good way to protect the derailleur during a fall - this will decide how much I spend on a new one!

This is the stuff that is crushing my derailleur every time I fall.

They make bash guards for derailleurs which mount to the frame which protect a derailleur in a crash like

but these are dangerous in that they transmit a hit to the derailleur to the frame (and frame damage is typically less repairable/ more expensive than a derailleur damage).

Usually, what gets damaged in a crash is the derailleur hanger, which can be bent back into shape with a special tool at your bike shop (Park Tool DAG-2 for example). You should never pull the derailleur into shape by the cage (this is the weakest part of the derailleur and can damage it more). On non-steel bikes, this is often a little replaceable part which is designed to deform in a crash so hopefully your derailleur makes it out alright as does your frame (so if you can't bend it back into shape, you can replace it).

Typically the Shimano Deore level is what gives you the best hit taking ability for the price, though it depends on how you fall and how the derailleur gets hit and stuff. The best thing to do is "don't fall". But obviously, compatibility within brands and budget dictate what to buy.

I'm curious as to how the derailleur is "bent", and how you're straightening it though. It would be good if you updated your question with a diagram or picture of your "bent derailleur", along with the type of bike you're riding.

Maybe you could change the whole drivetrain to sram x4 because it is cheaper then shimano slx, XT. But also it's cheaper to replace the derailleur on sram x4 for around 20 dollars.


Identify year of manufacturing of Merida frame by Serial number I'm trying to buy a used Merida Scultura Road frame, but the current owner does not know the year of manufacturing. It is possible to extract this information from serial number?

Serial:

WC 93055 B

BI - 1582 BR

Per comments from the OP, looks like a 2007 model.


Do you know the make of this BMX bike? Do you know the make of this BMX bike?  The only identifying mark is a stamped M on the rear of bike.

 Picture of frame stamped on trackend/dropout at right-rear of bike.

Surprisingly this is enough info to give a lead.

http://bmxmuseum.com/forums/viewtopic.php?id=1493 says

"Mongoose used the M on the drop outs of their frames in the early-mid 90's"
"Mosh stamps their frames with an old english "m"."

So your next step is to start browsing through http://bmxmuseum.com/bikes/mosh/ and  http://bmxmuseum.com/bikes/mongoose/ looking for a match.  There are over 5000 bike photos to compare - good luck!

Mosh logo on Downtube - can't find a photo of one on a dropout though.

It's definitely a Mosh. Just sold my Mosh skooled great build miss it already


Aspects for choosing a bike to ride across Europe I've been planning to do an "Orient Express" tour for a while now and I realised it would be a good idea to ask for advice regarding choosing the bike.
I was born in a mountainous area and used to ride a lot up until I was around 23, mostly on road and gravel, but featuring hills. "A lot" is subjective, I'm talking about 300-500 kilometres a month. I could do a 100 km day without issues.
I am now 29, have a sedentary job, did not cycle for a couple years, and choosing big goals is generally how I am able to make progress. I'm not planning to do the tour next week.
I need a proper bike for it, however.
The itinerary is Paris - Istanbul, a lot of flat areas, on the road, but I would also like to challenge some passes in the Alps, like the Furka in Switzerland.
I've travelled before with very little stuff and I don't need much luggage, just the basics.
I've been looking at a few bikes, the Trek 520, the Surly Disc Trucker and the Kona Sutra seem to stand out.
What are the aspects I should pay attention to when it comes to making a decision?
The one I like the most is the new 520 Grando, but I can't even try it since it's not available on European markets and I'd have to find a way to get it transported to me from the U.S.
I feel like I might be making a vanity decision here and for the purposes I need the standard 520 might even be a better choice.
TL;DR: I've fallen out of touch with the biking world and I would like to make a smart decision and not just pick something that looks "cool". Thank you for your advices

There are a few factors to consider.
How much luggage do you want/need to carry?
Stopping in hotels, or carrying a tent etc?
Is speed/efficiency important?
Can your flexibility/core strength support long periods in a more aerodynamic position?
You certainly can't go wrong with a traditional touring bike like the ones you mentioned, but there are other more modern and lightweight options available.
My personal preference for such a trip would be a race orientated gravel bike (like a Cervelo Aspero for example) fitted with bike packing bags. Fast, efficient and fun to ride, but with features that are good for touring like extra bottle cage mounts and top tube bag mounts.
But that is my preference for how I like to ride - others would have different ideas and priorities.  The best we can do is give ideas/options, but only your own preferences and experience can tell you the right answer for you.

I've been looking at a few bikes, the Trek 520, the Surly Disc Trucker and the Kona Sutra seem to stand out.

Those are some of the most reasonable bikes you can buy today. The optimum material for bicycle frames and forks has long been butted chromium molybdenum steel (chromoly) and with recent "inventions" such as aluminum and carbon fiber it's all been going downhill since chromoly.
If I was about to purchase a non electrically assisted bicycle today, Kona Sutra plus few modifications would be my choice.
Let us look at the specifications of those bikes and what problems they have.
A common weakness is that none of these bikes is sold with a front hub dynamo, so you can't have reasonable lighting solution without changing the front hub or the entire front wheel. Another common weakness is that all those bikes on the list have a triple crankset with a ridiculously small "granny" ring that's so small not even grannies would use it. Also as is typical of most bikes sold today, the spokes are not optimal: for today's hubs, 2.34mm/1.8mm/2.0mm triple butted is optimal but bikes are today usually sold with straight gauge or double butted spokes.
Kona Sutra:
In addition to the common weakness, you are paying a lot of money for a Brooks leather saddle that takes huge efforts to maintain, takes about forever to break in, and will be destroyed in the first rain.
The wheels in Sutra require an immediate change too: the 622-23C rims won't take reasonably sized tires (so the stock tires are 622-40mm, too wide) and the hubs are cheap no name Formula hubs -- but you would be changing the front hub anyway as it has no dynamo.
As good features in Sutra, it has thru axle (which is necessary for disc brakes to not be fatally dangerous), the frame is butted chromoly, the bottom bracket is apparently Hollowtech II, the bottom bracket drop of 72mm is about optimal if you choose a size with 170mm cranks (for optimal BB drop, calculate 240mm minus crank length for conventionally sized road tires), and there are disc brakes (although the brakes are mechanical not hydraulic -- good for maintaining, not so good for braking feel). The shifters, bar end shifters, are very reliable, not likely to break in a crash and can be operated with even thick gloves.
Trek 520 disc has more problems:
The frame has disc brakes and quick release wheels, a no-no. This is fatally dangerous. The front disc brake causes the front hub end to move slightly during braking, wearing away the metal, loosening the quick release, until the quick release is so loose the wheel pops out of the dropouts when braking hard.
The fork seems to be aluminum not chromoly. Fork is not the place to experiment with "novel" materials. If you are a fan of aluminum, choose aluminum seatpost, stem, cranks etc. And if you really like lots of aluminum, then perhaps the frame could be aluminum. But fork? No!
The rims appear to be 622-21C so you can't fit narrow high performance tires. The shifters, STI Sora, cannot be operated with gloves on, cost a lot of money, and are likely to break in the first crash plus are likely to wear away.
As good points in Trek 520, it has Shimano Hollowtech II bottom bracket, Shimano hubs (but you would be changing the front hub anyway as it has no dynamo), the frame is butted chromoly (although the fork is not), there are mechanical disk brakes (easier to maintain than hydraulic but poorer brake feel). The bottom bracket drop is 75mm or 70mm depending on the frame size, not totally unreasonable.
The weight limit of Trek 520 is stated as 125kg, leaving only 110kg for the cyclist and the cargo. A bit heavier cyclist and you're over the limit with no cargo. However, it could be the lawyers just wanted to play safe and put a low weight limit on it.
Surly Disc Trucker has problems too:
The bottom bracket drop, 80mm, is way too much for 170mm cranks using conventional road tires. You will be hitting the pedals to the ground in corners. Not only that, but attach 175mm cranks and the bike is nearly unridable due to its low bottom bracket. The handlebar is a strange riser drop bar which means if you need a new handlebar you can't find an identical one and a non-riser drop bar changes the geometry of the bike. The hubs are cheap Novatec ones (but you would be changing the front hub anyway as it has no dynamo). There appears to be no kickstand mount. The shifters are STI Sora with their already explained problems. The tires are ridiculously sized 41mm. The frame is unavailable with 622mm conventionally sized wheels in the smallest frame sizes.
As positive points in Disc Trucker, it has thru axles (good for disc brakes), frame and fork are butted chromoly, there are mechanical disc brakes (tradeoff vs hydraulic), and the bottom bracket is Hollowtech II.

My opinion is: get the Kona Sutra as it has the best frame+fork combination (for example the BB drop of Disc Trucker makes it unusable and the aluminum fork of 520 is bad experimentation). You will want to change the wheels anyway to get front hub dynamo, Shimano hubs, triple-butted spokes and 622-19C rims with double eyelets. The tires of Sutra need changing too to something like Grand Prix 5000 in 32mm size, and unless you're a masochist the Brooks leather saddle needs to be thrown away. If you find the non-optimal chainline of the triple crankset a problem, you can easily change it to a double one, the bar-end shifter makes it easier.


Should you use GT85 on your chain? I've been told by various sources that WD40 is bad for your chain so have avoided using it. I've seen people using GT85 on their chains but I'm not really sure how the two products differ. So my question is, should GT85 be used on your chain? Or, does it have the same damaging effects as WD40?

It appears that there are several products under this name, a general-purpose solvent/protectant and a dedicated bike chain lube.
Reviews on Amazon are rather mixed... One fellow claims no better than WD-40, others appear to like it.
Chain lubes are always controversial and seldom tested in a rigorous manner.

WD-40 is essentially a cleaner/solvent and has no  more lubricating ability than say...Kerosene.
The best chain lube I ever tried is sadly not being made any more... Schwinn Factory Wax.

Clean-running, persistent, and according to testing by Bicycling magazine, among the top for wear and abrasion resistance.

To my way of thinking, keeping the chain clean and free of built-up crud and goo is as/more important than what sort of lube used.

Oh My God! WD-40 is not a Lubricant! It is Water Dispersant-40th Formula. It was developed for the space race in the 50's to displace water to prevent corrosion due to moisture condensing on metal. It forms a hydrophobic coating not a coating of lubricant. Just because anyone can buy Duct Tape and WD-40 and use it on and for anything and everything doesn't mean you should. It' means that person doesn't know anything.


What should I use to lubricate my kickstand? The kickstand that came with my bike is rusty and is difficult to adjust. What should I use for lubrication?

Grease. You want a lubricant that will stick around. WD40 is a degreaser and is designed to penetrate, lubricate then evaporate. Which is great for removing something that's stuck. But for a kickstand you want it to keep working for a long time. So, grease.

GT85*, with excess removed :-)

*Or equivalent, even WD40 will suffice.


Determine miles on a bike I'm a beginner trying to get on a road bike. I've been shopping around for a new bike for the last week and am also toying with the idea of getting a gently used "pre-owned".

One of the guys I've talked to, has said that he has only put around 250 miles on the bike. Is there  a way to determine that this info is right? What do I look for to make sure that he is not bluffing.

250 miles is nothing. 2500 miles is also pretty much nothing -- this is under a year's worth of riding for many people. Many people still ride (and buy) bikes which are ~30 years old, and probably have 25000 miles or more on them (and will ride them for many years to come).

You can look at the model number (and compare it by year to which model year it is). But beyond that, you can't really tell anything, since a lot of parts which wear (tires, brakes) can be easily be replaced (and you won't know if they've been replaced unless you knew what was originally spec'd; and they could have easily been replaced due to other reasons, such as cutting a tire on some glass). Mileage isn't a good indicator of the condition of the bike anyway (you can easily have a bike which you've racked up 5000+ miles and looks and runs like new).

What you should look for is no cracks in the frame, a solid headset, true wheels, straight fork, etc. -- a 250 mile ridden bike which has been in a crash which damaged the fork is probably worse off than a 2500 mile ridden bike that was cared for.

We have several questions such as this one and this one on how to check out a used bike before purchase.

All that being said, most bikes which have really been ridden only 250 miles will have all their original equipment, and look pretty much new (no wear on the cassette, no worn chainrings, the original chain which likely hasn't picked up much dirt, handlebar grips and saddle looking like new, very few scratches, etc.). But there are bikes parked next to mine right now which have been ridden thousands of miles which look that way too, because someone took care of it.

Frame problems cannot be replaced. Everything else can be cheaply done. The cassettes can be replaced, so can bearings in the head set and bottom bracket. A broken bearing in the bottom bracket can cause major damage to a frame so that no future bearings will work. Turn the pedals with some weight, if there's any clicking, it's cause for worry.

If a bearing shatters and the pieces are then weighted, they will gouge the frame, so that the clicking, regardless of new bearings, will persist.

The fork is also a major piece that cannot be replaced easily, inspect it for warping, cracks, discoloration.

Note your location and the bike's origin; it helps if the local bike shop has replacement parts.

Stuff not to worry about:

brake pads are cheap to replace if worn
tires are cheap to replace, if worn
wheels are easy to true
handlebars and seats can be replaced, almost universally
cables can be replaced easily


What is a reasonable speed for long distances on a bike? I am curious what a reasonable speed to travel on a bike is.  Speed will obviously vary based on the conditions in which you are riding.  I am planning on taking the GPS out with me this weekend to see how quickly I go.  Before I did that I wanted to get some benchmarks.

For the most part I will be riding an older road bike on crushed rock.  (Very small rock, with good rolling resistance but still much worse than pavement).

I will also be riding that road bike on the road (i.e.: pavement in North America, Tarmac in Great Britain).

What is a reasonable speed on these two surfaces?  I am more interested in speed over long distances, i.e. if you were going 80 km what would your target speed be?

Speed varies widely by cyclist, depending on fitness, road conditions and traffic.  Some of my observations (cruising speed based on a flat, paved road in good condition):

20km/h (12.4 mph) - many "occasional" cyclists ride around this speed
25km/h (15.5 mph) - most commuters
30km/h (18.6 mph) - fast commuters, slower roadies
35km/h (21.7 mph) - fast roadies
any faster than that on a long flat and they're probably a racer

(based on who I pass and who passes me when riding around 30km/h)

Average speed will usually be slower than you think, once traffic stops and hills are factored in, especially over longer distances (like 80km).  On my 21km commute I'll hit 30+ on every long stretch I can, but my average still only works out to 24km/h.  For longer rides I cruise around 27-28 km/h, which is more sustainable; averaging 22-24 over a very long ride (200km) is a great pace for me.

My average is 20 mph to 22 mph on pavement while not going hard, but that's if there's a lot of lights, stop signs, etc. Today on pavement I went 28 mph to 30 mph over a distance of 24 miles. I'm really not too sure about tarmac. I think one might be a little slower on that, idk. Not really sure if these speeds are good or not for a rider, though, as I have health problems, including about 35 percent heart function ( so my doctors tell me, I never get out of breath on rides ) and that may make me slower, I don't know.


Do city bikes and hybrid bikes have different frame geometries that cause a performance difference? I currently have a hybrid bike with a flat handlebar that I ride on roads for exercise and leisure. I want to replace it with a bike with an IGH and coaster brake so that less maintanence is required, but all bikes I can find with that are "city" bikes. I've ridden a few city bikes before and they are much harder to pedal than my hybrid bike - on flat ground. Why is that?
Some factors are IGH vs derailleur, weight and tires. Two other factors are saddle height+shape and handlebar height+type. The two last factors can be mitigated on a city bike. But is there something intrinsic to a city bike frame that makes it comfortable for relaxed and lazy riding, but that makes it hard to pedal when you want to go fast? Or will a city bike be like a hybrid bike if the saddle and handlebar are adjusted/changed to reflect a typical hybrid bike?

There is no formal definition of city bike or hybrid bike so this question is hard to answer, especially as 'hybrid' can mean many very different  styles, some of which are slower than some 'city' bikes.
This is a more recognized style, the 'Dutch bike'

The rider is very upright, and there is an enclosed chainstay and mudguards to allow normal clothes to stay clean. Up to about 10mph the upright position doesn't slow you down because wind resistance is minimal at low speeds.
The Dutch bike may also be very heavy. On flat ground this is almost irrelevant, but it is unhelpful in hilly areas.
The gearing is typically an 3-speed hubgear. Whereas derailleurs are up to about 96% efficient, the IGH will be less efficient, however this is typically over 90%. While the drag is perceptible, this is not significant.

In many cases the slow speed will be down to the choice of tyres. A classic 'city' or Dutch bike should not get punctures on the 2km ride back from the pub, and so heavy, puncture-resistant tyres are much more important than shaving 5s off the journey time.
If you fit a Dutch style bike with racing tyres then on flat ground at 10mph then it should not be noticeably harder to pedal than a racing bike. However air resistance grows with the cube of speed, so at 20mph you will be creating a large amount of air resistance.
The most important factor in resistance is not particularly the 'aero' of the bike, but the rider's position. The term used is CdA, which is drag * area.
If you compare the Dutch bike above to this time trial cyclist

then the area exposed to the wind is much greater. In addition, it is obvious that a slippery lycra-style suit bent over parallel to the direction of travel, and an aero helmet is going to disrupt air flow much less than an almost completely upright cyclist on a Dutch bike.
Refer here: https://www.gribble.org/cycling/power_v_speed.html
Basically if you are happy to travel around 10-12mph or so then a very upright bike is suitable. If you want to travel sometimes at 20mph then an upright bike is a big waste of effort.
It is possible to get a lower position on a flat bar bike with a different handle bar. The Jones H-Bar is one design that allows a crouched position on a flat bar bike.

In addition other modifications such as a lowered stem could help with this.
In terms of your question then the geometry of a city bike is going to be much further from a road bike, so not suitable for say 'leaning into corners', and not very 'fast' in handling, but this isn't really what is slowing you down, which is overwhelmingly tyre choice at lower speeds and then body position and clothing at higher speeds.
If you just want 'low maintenance', then remember that something like a Rohloff is extremely efficient as much as derailleurs, very low maintenance, and can be fitted to racing-style bikes.
This is more a 'gravel' or 'adventure' posture than racing, but it should be faster than your flat bar hybrid (Shand Stoater w/ Rohloff IGH)

It's very expensive of course, but if you have money then you can have your bike built how you want - don't expect to find a cheap racing bike fitted with a cheap 3-speed hub, but if you want a low maintenance bike with IGH and a faster speed than bolt-upright Dutch style, then looking at something like a touring bike might be helpful.

I currently have a hybrid bike with a flat handlebar that I ride on roads for exercise and leisure. I want to replace it with a bike with an IGH and coaster brake so that less maintanence is required, but all bikes I can find with that are "city" bikes

It may be a bit tricky to find a suitable replacement bike. Most "city" bikes indeed have a different geometry because they are intended for short trips of at most 5 km. Those bikes indeed have worse aerodynamics and a position less efficient for exercise.
Some of the drawbacks to consider:

It is very hard to precisely adjust the braking power of the coaster brake with your legs. Thus, you should treat it more of an on/off brake. The rear tire will wear faster with such a brake, and it can even be dangerous in slippery roads (snow / ice). Good luck for 50%/50% front/rear braking on slippery roads -- the front is operated by a hand lever, the rear by backpedaling and you can't adjust the brakes to have equal braking power if their operating mechanisms are different.
Even though coaster brakes do not require maintenance, they have a finite lifespan. Usually the intention is that the entire bicycle with its coaster brake is probably replaced before the end of the lifespan. Although coaster brakes can be overhauled, it may be tricky to find parts and a mechanic knowledgeable in coaster brakes. Thus, the "no maintenance" feature may actually be a bad feature.
The coaster brake is on the wrong wheel. During the summer when the roads are not slippery, I use only the front brake 99% of the time. Coaster brake with its reduced maintenance requirements thus would stay unused. So perhaps the finite lifetime of coaster brakes is not a problem because it will be unused? In fact, I use the rear brake only when there is poor traction and that's when I mix both front and rear brakes. Precisely adjusting the rear braking power is something you can't do with a coaster/hand-operated brake operation mix.
Even though hubs gears are usually left unmaintained, strictly speaking the hubs should be ideally opened and relubricated to have the maximum possible life. If derailleur bicycles in your area are prevalent, good luck finding a mechanic that knows how to relubricate internal gear hubs. In fact, internal hub gears are more complicated mechanisms than standard hubs so strictly speaking they have more maintenance required. Usually the hub maintenance is omitted so that's why these are considered low-maintenance. But you have a finite lifetime with omitted maintenance.
It is hard to fix a rear puncture in an internal gear hub. Even harder if the hub has a coaster brake. The effort to fix a rear puncture is practically impossible if you have a requirement that your hands must not be stained in chain lubricant. The rear tire will be the tire that will have the most punctures. The puncture repair needs new tools not needed by a derailleur bicycle (adjustable wrench -- it may be tricky to find a wrench light enough to always carry with you that still has a big enough jaw opening for the hub nuts).
The most common form of maintenance, chain lubrication, is still necessary
The second most common form of maintenance, chain and sprocket replacement, is still necessary. The only difference is that if you delay chain replacement, the expense won't be as great -- this lower expense of delay is in fact the reason why internal gear hub bicycles are considered to have lower maintenance requirements. You can let the chain destroy the sprockets and still consider the expenses acceptable.
An internal gear bicycle adds a new form of required maintenance, chain tension adjustment. A derailleur bicycle does it automatically for you.
The opportunities to continue your journey with gear mechanisms failing are limited. In contrast, with a derailleur gearing system, you can nearly always devise a get-you-home solution with lightweight tools you always carry with you.

Because of those drawbacks, internal gear hubs are ideal for riders that walk and push the bicycle home when getting a puncture. This means less than 5 km journeys. Derailleur bicycles are ideal for those who are able to perform basic maintenance themselves and carry a lightweight set of tools everywhere they ride the bike.


Why ride a fixed-gear bike? I must confess, I don't know much about bikes.  Until fairly recently, a bike was just that thing that I rode to work each day.  I've been slowly learning more about bikes but I still have some newbie questions.  This is one of them.

If I recall correctly and have got the terminology correct, a fixed-gear bike is a bike with only one gear (so you can't change it) and no freewheel (so if the rear wheel is turning, so are the pedals).

Why do people ride fixed-gear bikes?  Isn't it either hard to get started (if fixed in a high gear ratio) or hard to get to a good speed (if fixed in a low gear ratio)?

I'm not trying to insult or flame riders of fixed-gear bikes - I'm just curious! :)

Your understanding is correct.

Why do people ride them? Some random answers:

Maintenance is very, very low. You have to keep the tires and chain in good working order and, on a bike you ride on the road, hopefully some form of a brake. That's it.
On most velodromes, you have to ride a fixed gear bike, so if you race track, you have no choice.
There is something to be said for how a fixed gear will force you to develop a smoother pedaling style since you simply cannot stop. Due to this, they are somewhat popular for 'off season' training by serious road cyclists.
(Hesitating to mention this...) There is a certain segment of the population that loves retro and simple things. In addition to being possibly the most efficient people moving device that exists, the fixed gear bicycle can be an important fashion accessory.

Hard to get started/Hard to go fast?

Yes. Generally someone who has a road worthy fixie will have selected a gear that works well for the terrain and speed that they like to ride at. I've only ridden fixed gear bikes on the track, but I'd imagine for a city fixie, you'd optimize for a fairly low speed but someone who takes these more seriously can answer better.

Fixed gear bikes can be very silent. All you hear is the tire on the road. I don't think you can get that with any other type of bike.


How can I offer a test ride while selling a bike? I am selling a bike to someone I don't know from Craigslist. I expect that the prospective purchaser will want to test ride the bike before making the purchase.

How can I prevent  them from riding away with my bike during a test ride?

The simplest answers are ask for their ID, or for their car keys if they arrive by car. There are plenty of other options on various forums like

https://www.bikeforums.net/general-cycling-discussion/446194-selling-bike-craigslist-test-rides.html

https://www.bikeforums.net/general-cycling-discussion/687171-how-do-you-let-potential-buyer-test-ride-your-bike.html

Make them bring their car and a friend (partner, familymember) and make the friend wait with you in their car. Then they have to be violent to get rid of you (forcing you out of the car) which means they have commited a much more serious crime than not returning a motorcycle.


Is a fatter tire likely to get fewer flats Everything else equal is a fatter tire likely to get fewer flats

Actually misread another question
Is a bigger wheel likely to get fewer flats?
So I am posting this question to match my answer

The two most common types of flats are
1) pinch
2) puncture

Can also have the spoke puncture the tube from the inside but nothing a tire can do about that.

A fatter tire is more resistant to both pinch and puncture flats.

A larger tire will also have softer ride (due to lower pressure) and better traction due to more tire in contact with the road.  This durability and comfort come at a cost.  A larger tire is heavier, more wind resistance, and more rolling resistance.

Wheel sizes are reported in a number of ways.
The actual actual wheel size or actual wheel size plus nominal tire size.

For sake of fair comparison I will use actual wheel size.
For example ISO 622 is the same as both 700mm and 29".

Will compare ISO 622 wheel diameter and tire diameter of 1" versus 2".
Same rubber in each tires and same thickness.
A fatter tire will tend to be thicker but for the sake of head to heads comparison assume same thickness

The tire must support the weight of the rider and bike.
If I am 170 lbs and 60% of the weight is on the rear wheel then let's call it it 100 lb on the rear wheel.

The 2" diameter tire will run at a lower pressure.
Let's assume the 1" tire runs at 100 PSI and the 2" at 60 PSI.

A bigger tire runs at lower pressure because it has more contact area.
In this example the 1" tire will have a contact area of 1 square inch.
And the 2" tire will have a contact area of 1.67 square inches.

Pinch Flat

Pinch flat is when the tube is pinched against rim and splits open.
When you hit a blunt object such as a curb.

A larger diameter tire is more resistant pinch flat for two reasons
 1. With the larger diameter the outer tire (starts) further from the curb.
 2. Due to the bigger diameter the  fatter tire builds surface area faster so it does not need to deform as far to match the force of the curb.

Puncture Flat

A sharp object penetrates tire and tube.

Identical rubber will have the same force per surface area to penetrate.
The rubber does not know if it has 1" or 2" or buddies.

Assume a triangular piece of glass 10mm by  10mm by 10mm.

Along comes this this fat soft tire.  The tire deforms and the rubber makes contact with the road around the glass like the glass is not even there.   Because the tire deformed and made contact with the ground the glass never exceeded the minimum force to penetrate the tire.

Even if the fatter tires comes in contact with more glass is still distributes the load.
Would you rather stand on a bed of nails of lie on a bed of nails.

Then along comes a hard shinny skinny tire that cannot absorb the glass and at the point it is just tire on glass there is sufficient pressure for the glass to penetrate the tire.  The higher pressure tire did deform but not as much as much as the lower pressure tire.  In this example when the tire was directly on the glass no tire was in contract with ground to take the part of the load.

A smaller piece of glass in which both tires deform and touch ground around the glass the softer (lower pressure) tire is always going to have more tire on ground around the glass and take more weight off the glass.  The large tire is going to take enough weight off the glass to avoid penetration for a range of heights and sharpness.

This is not an artificial condition.  A glass bottle is about 4 mm thick. The small sharp shards of glass from the bottle are 4 mm.

Even a piece of glass that penetrates both tires the glass will penetrate the harder (higher pressure) tire further.  Because of deformation the glass will not be pushed in all the way.  Again the softer tire has more deformation.  So could have a case where the glass penetrates the tube on the hard tire but not the softer.

If you ride the same piece of glass long enough it will eventually works its way into both tires.  So inspect your tires for glass.  On a regular basis.  For sure every time you air them.

Tire Pressure

Tire pressure effects both pinch and puncture flats (and rolling resistance).

Increase pressure reduces pinch flats.

Increased pressure increases puncture flats because the tires does not deform as much (spread the load).

So there is a sweet spot.  Go with the manufacturer for that sweet spot.  Tire will have a pressure range.  If you weigh 180 of more then use the maximum.  If you wight 140 of less then use the minimum.  In between use liner interpolation.   If you weigh 160 you are 1/2 between and should use the pressure 1/2 way between.

Mountain bikers like to run at lower pressure for more contact (traction) and to absorb  roots and rocks.  If you are running at a lower pressure then be aware and don't bang on roots and rocks as hard.

Tubeless

Tubeless tires offer the advantage of no tube to pinch so no pinch flats.  Can run them at a lower pressure.  A tubeless tires with sealant is not less susceptible to a puncture flat but it will seal small punctures.

The top answer makes a good case, but in practice, I don't think it's true that wider tires puncture less easily WRT broken glass, or especially pinch flats. A narrower tire designed for higher PSI avoids more obstacles & presents a much stronger surface. Higher PSI tires are under great tension holding in the pressure. I think this pre-loading makes them more durable (in a similar way as how case-hardened steel & bulletproof glass get their characteristics from rapid cooling processes locking in internal forces w/ the outer layer under great tension), plus hi pressure tires may need to be made w/ stronger materials in the first place. Glass is very brittle & firm tires seem to crunch the sharp edges off at moment of impact, continuing on unscathed, so they don't seem more vulnerable to direct puncture. The danger with glass is more when the tires pick up fragments that can sometimes work their way deeper. There may be advantages to mountain bike tires that have knobby tread, but keeping all things equal & assuming similar treads, a softer bigger tire can pick up more glass more easily, so I still think it's at the disadvantage.

IME, high pressure tires have much less give, & therefore are much less prone to pinch flats. I've found that hitting a sharp bump while under moderate to heavy-moderate braking, for instance, can cause a pinch flat very easily on tires under 35 PSI, occasionally on tires 35-65 PSI & it's definitely never happened to me on the current tires I run at 90-100PSI.


How do hand signals vary between countries? There are several conventions on how to signal properly

The simple method (straight left arm = left, straight right arm = right)
This answer on SE depicts a left-arm-only way of signalling (straight left arm = left, bent 90 up = right)

I'd like to know where should one use which singalling convention? I'm personally mostly concerned about Europe, but let's keep the question general.

Both question linked by Neil are rather comprehensive for the US and UK. Wikipedia (though not the greatest resource) seems to have a nice, even if short, list of arm signals in various countries.

I live in Denmark, and while I couldn't find a trusted resource for it (there are a number of blog posts, though), I'd say the convention is to use straight left and right arm signals. And in reality they are something between a straight and a bent arm, so it only matters which arm is used.

Finally, Lithuanian traffic rules (note: it's in Lithuanian) indicate the following:

To turn right, use straight right arm or bent left arm
To turn left, use straight left arm or bent right arm
To stop, use either left or right arm straight up

In countries where you drive on the right side of the road (the US, and most European countries), you should signal with the left arm. That means:

Turning right: signal with a 90 degree bent left arm out to the side,
pointing up.
Turning left: signal with a straight arm out to the side, straight
out.

The reason to use the left arm is that your left brake is the front wheel. If you have to brake in an emergency situation, it's usually better to heavily use the rear brake. If you only use the front brake, there's more of a danger of going over your bars.

In countries such as the UK, where you drive on the left hand side of the road, brakes are reversed. So signal with the right arm.

Generally, pointing clears up some ambiguity compared to a bent arm, but is less safe for the cyclist when turning right (or left in the UK, etc.).


How often should I check rear derailleur adjustments? If I remove the (rattling)plastic disc  -

How often should I check the limit screws on rear derailleur?
If the shifter cable tension is less than optimal, would this be a possible cause to drive the chain in between the spokes and the rear cog-set?
Excluding the case of debris getting stuck in drive-train; are there any other adjustments besides above two and true-ness of rear wheel that may cause the problem of getting chain between cogs and spokes?

Derailleur in question is a Shimano Deore.

Update: Details- For mileage, I commute about 110 miles/week.

It's really up to you how often to check your adjustments, but I'd say it's not an "every ride" kind of check, unless you're giving your drivetrain a workout! If there's any damage to the derailleur, hanger, or rear wheel, you may want to start there as well.

To specifically address your questions:

You should check your limits any time you have a drivetrain issue. That could be poor shifting, dropped chain, or inability to shift.
Shifter cable tension should only affect how easily/quickly the derailleur moves. However, there could be a case where too much tension could cause the derailleur to move through the last shift enough to stress past the limit screw, but I think this is unlikely.
The rear wheel could be out of dish (centered from side-to-side) which might have moved the cassette further in. Readjusting the limit screws should take care of that, but you might still have shifting issues. (I had the same problem this spring)

I'd say every week twice. Monday and Thursday are good.