Why is the swingarm design uncommon / rare on full suspension bicycles? While watching a snow biking video, I saw that some of the bikes use a true swingarm design, which matches most motorcycles (as does much of bicycle technology). While this looks rather interesting, I'm wondering why it's so uncommon (and much more common are multi-linkage, seemingly more complex designs)?

I've found the bicycle he was riding, a Chumba F5, shown here:

Upon more searching, it's also used on Mountain Cycle Fury Frames and Motoped Kits as well, but an overwhelming majority do not use this design.

If I had to guess, I'd say it was solely weight concerns to not use this design with less moving parts. It also (seems to) allow for more travel, so is there perhaps an upper limit on how much travel you can get with the multi-linkage design?

Further, I've seen the Y-Frames (especially on BSOs) criticized for having poor flex characteristics. Does it again just come back to the weight issue in that more reinforcement is required for these designs?

This swing arm design has fallen into near complete disuse in the bicycle world for 2 reasons:

First, there is translated suspension activation from pedaling. This design does not isolate pedaling or other rider generated forces from ground generated forces. Because of that, there is a loss of efficiency which makes it a poor choice for a bicycle suspension design.
Second, the travel path of a single pivot swing arm carries the wheel forward as it moves through its travel path, because of the arc described by the wheel. If your rear brake is in use, the wheel is prevented from following that arc, and some or all of your suspension travel is lost until the brake is released. In a 4 bar linkage design, or similar vertical travel design, brake activation does not prevent suspension activation. Thus it has become the default design for high quality dual suspension bikes.


holes on the inside of metal fork blades, what are they I noticed there are two very small holes on both blades on my new fork. They are on the inner side of the blades at the end of the fork blade just above wheel axis mounting point. They are apparently designed to put there because they are at the same position and holes are smooth and no damage. So what the purpose of these holes? I noticed that my old fork also got similar holes, which I never noticed before.

On steel forks the tiny holes at the bottom end of the fork-blade are vent holes for the brazing process. The brazing produces fumes the fumes and the heat expands the air in the blade which makes that these holes are needed to evacuate both. On steel frames you may find similar holes in the seat-stays and in the chain-stays where they are usually close to rear drop-outs.
If you're worried about rusting because of moisture that could go inside spray some wax-coating or tar-based antirust inside, or a periodic jet of penetrating oil as I do.


Is there a do-it-yourself way to tow a kid's bike? We drop our kid at school in the mornings, and I'd like to bike over to pick her up after school.  I've picked her up on our tandem (that's one reason I got the tandem), but she'd like to ride her own bike some of the time.

So I need a way to take her bike with me, something like this, I guess:

...except I don't need to be able to support the weight of the kid on the bike, I only need to be able to tow a riderless bike.  So I'm trying to find a way to do the same thing that's cheaper (hopefully) and lighter (and maybe smaller?).

One possibility (that I'll try) is to simply strap her bike to the back of the tandem.  I'm sure that will work, but I'd also like a system that works if my wife is the also riding the tandem and a system that would on a single bike.

If the child's bike has a quick release front wheel, you could also use a universal fork mount bolted to a rear bike rack. Then just hang the front wheel on the kids bike with a bungee cord.


How do you remove the sprocket from an eighthinch splined BMX style crankset? I have the EighthInch Freestyle Splined Crankset. These are very similar to profile bmx cranksets.

I purchased a larger sprocket to use with the crankset. I've used a crank puller to remove the drive side crankarm, but couldn't figure out how to remove the sprocket. It won't just slide off the axle. It fits on the crankset with very small splines. What should I do to remove the sprocket (aka chainring)?

Tap tap tap tap tap.

And then tap tap some more.

If this is what I am thinking of you either tap the inside of the chainring from the non drive side. Or you tap the spindle from the drive side which should push the spindle through the chainring and bottom bracket. Or a little of both.

Tap tap with a wood block.

Greasing before install goes a long way to make these things easy. They are made to be tight!

You could improvise a automotive gear puller but the hammer should work.


Replace or repair derailleur? Typical situation.  Derailleur goes into a wheel (for whatever reason) and rear derailleur cage is bent.  If you were a customer would you rather have the derailleur replaced and know it is fixed, OR have a mechanic attempt to repair it by bending it back or replacing the cage and accept the problem may not be fixed the first time?

Yes, the replacement is more expensive, but is a sure fix.  Replacing parts or manual adjustment may be cheaper, but introduces doubt into the repair and in all likelihood may work in the shop only to fail in use.  Then a customer would return, upset the repair failed.

My stance is replace it and remove all doubt.  Been asked as a mechanic to "make do" one time too often and want some outside input.

Repair or replace?

Replacing it is the more economical option in almost all cases, especially on lower end stuff (esp. once you include labor) -- you can't source the parts for many lower end derailleurs.

On higher end parts it may be possible to send it out to a company which rebuilds derailleurs or rebuild it yourself with parts, but again, the labor and parts will likely outweigh the cost of just getting a new one (and the new one is less likely to fail; the rebuilder may make screw ups).

So, I'd almost always replace, unless I had a good reason not to (e.g. someone who insists on vintage parts and wants that vintage part repaired). Or if its a tiny deviation (which wouldn't occur if the derailleur went into the wheel; that's generally toast).


What is this tool for? I recently found this in my cycling shirt. I don't know where it came from, and what it is used for. It reads "Simson" on the other side, but I have no clue what I could use it for. Does it have anything to do with spokes?

It's a spoke wrench.

Similar to this one:

http://www.btosports.com/p/bikemaster-spoke-wrench


How to adjust hydraulic disk brake lever reach during bleeding? During a crash I have bent my adjustment knob on Sram Code brakes and now after bleeding the lever is a bit too far away for my liking. The knob is bent and can't be turned. If I'll reduce the pressure in the system will it do the same as turning the knob out to make the lever closer? If so, is there any recommended procedure to reduce the amount of brake fluid in the system?

You cannot reduce the amount of fluid in the working part of hydraulic brakes. The reason is that hydraulic brake systems automatically draw fluid from the reservoir to compensate for brake pad wear and gradual advancement of the caliper pistons.

The way this works is when the levers are at their 'at rest' position the  reservoir is connected to the rest of the system allowing fluid to be drawn in. The first part of the travel of the piston connected to the lever cuts off the reservoir and allows the caliper pistons to be pushed out to apply the pads against the rotor. This is also why you can push the caliper pistons back in when replacing pads.


What tool do I need in order to remove these pedals? I own this set of HT pedals. They were attached by a mechanic at a bike shop. I'd like to avoid a return trip and remove them myself.
Most articles I've found about removing bike pedals mention a tool called a pedal wrench or pedal spanner. However it's not clear if that's what I need in my case: it's not immediately obvious to me that my pedals have the requisite surface for that tool to grip. Most of the how-to articles mention, as a secondary option, that some pedals are removed via a hex wrench. I'm currently inclined to think this is the correct solution in my case: I can see a spot on the opposite side of the crank arms from the pedals that looks like it'd fit a hex wrench. But I can't confirm this and HT's website is completely unhelpful.
Which tool do I buy? And If I do in fact need a hex key, which size should it be?

Depends on the pedal exactly how to remove, but there are two main methods.
You need to look closely at your pedals and see what they have.  I've searched but its not visible on any website/review.

Wrench flats on the side of the axle allow a spanner.  These are often 15mm apart, so a 15mm open-ended spanner may work, but a proper pedal spanner (wrench) is thicker than a cone-spanner but thinner than an adjustable spanner/crescent.  They're often longer than a normal hand tool, for added leverage.  See photo:

Hex driver in the end of the shaft - this is common on clipless pedals.  The size is often 8mm or 10mm, with bigger providing more torque and also more weight saving.  A pedal thread is 9/16" or 14.3mm, so a 12mm socket is very unlikely, that doesn't leave a lot of metal.  You might find weird sizes like 9mm or 11mm, so make sure the tool has a good tight fit before applying leverage.

Some pedals have both wrench flats and a hex socket, doesn't matter which you use.
If you don't own hex drivers, then buy a decent set of P-handle ones with 2/2.5/3/4/5/6/8/10mm.  Avoid buying one tool at a time, that's the most expensive way to acquire tools.  Personally I've never been able to remove a pedal with a multitool - there's simply not enough leverage.

The single most important thing to know when replacing pedals is the THREAD is left-handed on your LEFT hand side of the bike.  So the common "righty-tighty lefty-loosy" is opposite when you remove the pedal from the non-chain-side of the bike.
And the followon is that if you use a hex driver on the inside of the crank, its also reversed.  So slow down and think before you add a lot of torque, lest the problem get worse by stripping a thread.

Reassembly/refitting a pedal:

Use grease or assembly lube on the threads.
Make absolutely sure you're putting the right pedal on the right crank, and the left pedal on the left crank
Make completely and utterly sure you're not cross-threading.  Easy to do, and will ruin the crank arm.

Further reading: https://www.parktool.com/blog/repair-help/pedal-installation-and-removal


Can any bike crankset be exchanged for another? I have a Specialized HardRock from the '90s.  It's seen better days, but I got it for cheap.  I had a bike shop look it over, but for some reason the guys missed the rounded off teeth on the front gears.  Whenever I ride it, the chain slips every few rotations.  I'd like to get a new crankset, but i'm not quite sure what will work and what won't.  Any and all advice would be greatly appreciated.

The main intercompatibility issues with cranksets are the connection between the crank arms and the bottom bracket spindle.

Most bikes from that age (not to say all mountainbikes) use square taper bottom bracket, for which is very easy to find good quality cranksets.

These look like the leftmost spindle in the picture above (which also show newer types, that are less likely to be what you need):

You might also take a look at the page from where that image came, in the excelent website of Sheldon Brown:

http://sheldonbrown.com/bbsize.html

Other compatibility issues might be related to the length of the bottom bracket and the length for which the crankset was designed. Using different-sized bottom brackets and cranksets might result in a misaligned chainline, an ill-working front derailer, or in extreme cases a chainring running too close to the frame. This is so for tapered square, but I am not sure about the other types.


Post cyclo cross race bike cleaning and lubrication for you bottom bracket? If I wash down my bike after a muddy race cross race or training ride I usually dry everything off and then begin lubricating the chain and sprockets back up once it has dried. The only place I don't do this is the bottom bracket, it this something I should be doing as I have gone through one bottom bracket per year for the last three years or is this normal?

Modern Cyclo-cross bikes typically used  bottom brackets with sealed cartridge bearings.  No real maintenance required, except to replace when worn out. When cleaning your bike, be careful as high water pressure can force debris past the seals and into cartridge bearings. Once a year replacement is pretty typical for bottom brackets with outboard bearings.  Sad, but true.

As an aside, why are you lubricating he sprockets?  This will attract dirt.  The only place you want lubricant is inside each bushing on the chain and really no where else.  This is why everyone talks of wiping a chain down after lubing (and allowing time for the lube to penetrate the bushing assembly).  The only reason I can see for leaving lube anywhere else on the drive train (e.g., sprockets) is if you have inexpensive components that rust easily.  Even then, a little bit of surface rust doesn't really affect drive train performance, it just doesn't look pretty. (Surface rust being the key, a chain rusted into a giant block is of course pretty inefficient to pedal on.)


What is the weight difference between frame sizes? I was wondering if any one has an idea of how much more weight a larger size bike weighs. Specifically S-works Tarmac. So for example what would the difference in weight be between a 56 compared to a 61? 100g, 400g any idea?

According to the Weight Weenies.com web site listed weight can differ from actual weight by as much as 10-13%. One thing you should be aware of is there is some variations between identical frames due to manufacturing  tolerances. Most weights listed in advertising literature are not for large frame sizes. Looking at the listings on the site it appears that a 20-40 gram difference between carbon frame sizes is about the average.


Waht is the difference between Shwalbe's Basic compound and Performance compound tyres? Schwalbe produces a wide range of tyres. Their "Basic compound" tyres are twice cheaper than the same model but with "Performance compound".

Anyone have user experience with the two product lines? What are the practical differences? Are the Performance line MTB tyres made of "soft" rubber, that provides superior grip?

A simplified way to think about this is a tire has three core attributes: performance, durability and cost, but you can optimize for only two of them.  That, and marketing, is what seems to be afoot.

Schwalbe's web site has some general information on the construction of tires.  A takeway is they can tweak the rubber compounds to improve a tire's characteristics for specific needs. Their very high-level/marketing view list enumerating compounds equates the "Triple Star" compound as the best family, but it's tuned the specific user type mountain (grip, speed), road (speed, weight) and touring (durability, fewer flats) use.  It's not that different from 105/Dura Ace vs XT/XTR.

It may be more helpful to consider their suitability ratings within each category.  For example, under the All Mountain, the Nobby Nic (with the PaceStar, the high-end compound) is touted for its grip in soft surfaces and decent on hardpack/loose.  Its other virtues are comparable to the Rapid Rob (standard compound) at approximately 60% of the cost.  Thus if grip on soft-pack is really important to you, you might be willing spend more.  Skimming through their touring tires, there does seem to be a tradeoff between speed/grip and protection/durability.

Schwalbe's breakout seems reasonable, though I'd like to see some comparables with other vendors for calibration, ideally by the folks at Bicycle Quarterly who have done work trying to quantify aspects such as inflation pressure vs tire width.

Hope this helps.


Gear cable replacement I need to change the rear mech  inner cable on my Giant Fastroad slr1 (2016). The cables are run internally through the frame, but I need to know if it is a continuous outer sheath or is in sections, does anyone know please?

Specific to your bike?  Nope, no idea.

But you can test if its a full housing by push/pulling the housing where it enters the bike and see/feel if it moves at the exit point.  This is often visually like a wire disappearing into a wall.  By threadding the NEW inner into the OLD outer in place, you can then pull the OLD outer out the back and feed a NEW outer up using the NEW inner as a guide.  Its easier to do than describe.

If that doesn't help, release the inner wire down at the mech to give you some slack.  Then gently pull the outer away from the frame entrance or exit.  You will probably see the inner cable disappear into the frame.

Try and pop any cap or cover loose.  If this works easily, then your bike has no guide pipe inside the frame, because you can tape the NEW inner to the OLD inner and guide it through.  You'll want to pre-fit the new outers at the front of the bike first, and probably end up having to cut the head off the OLD cable.

The hard thing now is risking whether there's a guide pipe inside the frame.

You might get an idea by feeding the OLD inner into the frame at both ends and listening for a "tink" of the steel wire hitting the frame on the inside.  Won't help on carbon bikes.  If you DO hear a metal tink then its probably not piped inside.   If you DON'T hear a tink, means nothing.

Basically now you have to pull the inner and then push a new one in and hope that it doesn't drop into the frame.

Specific to your bike, I see this image:

Zoom in and there's a loop of black inner cable that drops out just in front of the bottom bracket and loops underneath.  Look to be a medium sized square/rectangular plate that may undo.

Please have a close look there and see if the plate comes off easily.  Do take some clear photos and post them in your own answer, showing how you found it.


What kind of rear wheel do I need? Recently my bike rear wheel was hit by a car at a traffic light. Now it's bent a little and touches the brake. It cannot be fixed by adjusting the spokes and I am going to need a new one. My bike is Schwinn varsity 1200. Here are pics of the wheel.

Look carefully at the tire, there should be markings on it that indicate what size wheel it is - generally 700 is a road-bike standard. 26 inch is a mountain-bike standard.

This is a good resource.

http://www.sheldonbrown.com/wheels.html

Also an option is the number of spokes, the more there are, the stronger and more abuse resistant the wheel is generally. Also consider do you have Shimano or another drivetrain- there can be compatibility issues.


Spoke wrench conversion master guide I have a universal spoke wrench. It used to work on any spokes I've owned, until now.

I have a bike with 2mm spokes. The nipples are between a 13 and 14 on the universal spoke wrench's sizes.

I have been able to find a mapping of gauge to mm/in.

I have not been able to find a definitive, trustworthy mapping of gauge/mm/in spoke measurements to gauge/mm/in nipple/spoke wrench measurements.

Can anyone please answer with a definitive, trustworthy mapping like this (except correct):

Spoke Gauge |  in  |  mm  | Nipple Gauge |  in  |  mm
         12 | .036 | 2.3  |            8 | .04  | 3.6
         13 | .076 | 2.4  |            7 | .05  | 3.7
         14 | .016 | 7.6  |            6 | .06  | 3.9
         15 | .026 | 2.3  |            5 | .08  | 5.2

Nipple wrench flat sizes don't correspond to spoke gauge in as clean or universal of a way as you're suggesting.

This depends a little on where you are in the world (and in history), but 2mm aka 14g spokes are by far the most common for bicycles, and there are three different common size nipples associated with them: 0.127", 0.130", and 0.136". (These correspond respectively with the black, green, and red spoke wrenches that several tool companies use.) Of these, the 0.127" wrench flat size is the standard one for 2.0mm spoke nipples by all the modern premium quality spoke makers (DT, Sapim, Wheelsmith, Marwi), and the other two are used seemingly at random by various lower-tier spoke/nipple producers.

Nipples for 1.8mm/15g spokes also almost always have the 0.127" wrench flat size.

2.3mm/13g spoke nipples can have either the 0.136" size or one of the more "oversize" standards like 0.156".

So there is no 1:1 mapping, especially because looking back into history there can be found any number of now-unusual permutations. The gauges listed on ring-type spoke wrenches are arbitrary and outmoded in actual use even if once they were based on some kind of real system.

Also, spoke wrenches in shop use get a lot of reps and do develop slop and eventually wear out.


How to keep my feet cool in cycling shoes? I went mountain biking yesterday, when the temperature was 100F / 38C. This is in Southern California in June, so that's not that unusual. The only issue I had is that my shoes get uncomfortably hot, especially the toes.

The trail I rode is just a climb to the top, then a descent back down to the start. There's no shade, and until the descent, there are no opportunities to get airflow that would help cool things off.

My shoes are SIDI Dominator. Black, of course.

I have a similar problem with my road shoes, which are the SIDI Genius 5. It's not as bad, because I'm usually moving much faster on the road, but it's still bothersome.

Buying new shoes is not an option right now, so I am looking for ideas to alter the shoes to be cooler. I want to avoid cutting holes in the shoes, so I came up with two options:

Paint the shoes white or silver. Black absorbs heat, white should reflect it.
Tape some foil on the shoes, especially the toe box. This will look goofy, and durability is questionable, but it should offer the highest level of reflection.
Duct tape. I'm thinking of the classic grey duct tape. Simple, durable, and probably a decent reflective quality.

Anyone have any better ideas?

No socks, and soak the shoes in ice water, they will eventully dry out, but whilst wet they will help disipate the heat.


Does the price difference between a Brompton and a budget folding bicycle represent quality I understand the difference between a cheap and expensive road bike as I have owned one of each. My question relates to an example of two polar-opposite folding bicycles; a budget £129 bike and a £759.99 Brompton.

Is the £630.99 price difference a result of better components or is the Brompton brand the justification?

Is there a minimum price that needs to be paid to ensure that a folding bicycle doesn't contain budget components?

Brompton is certainly a well known name in the bike industry. As such, I have faith in their ability to produce a quality folder.

The £129.99 bike uses a design which is sub-optimal for a folder, since a single failure point has the option for the bike to collapse into the folded or partly folded position. Which is not to say it will fail, only that it could, and there does not appear to be a safety.

In addition, the components on the bike appear to be the very basic type whih I would expect to see on a kid's bike, as far as quality.

Brompton may not have high end parts on this machine, but they appear to be at least ridable quality.

Whether the difference is worth it, is a personal decision, but I would not consider the £129.99 bike safe to ride for me or mine.


What are the advantages and disadvantages of riding a smaller Mountain Bike frame? I am 182cm (5' 11'') tall and am looking into buying a new frame for my mountain bike.

Right now i have a 19'' frame and i found a good deal on a 17'' frame.

The guy from the shop told me that it shouldn't be a problem for me to get a 17'' frame since you can have a longer stem and seat post so its fits alright.

Smaller frame means lighter but what are other advantages and disadvantages ?
Would you choose a smaller frame ?

Update
The difference top length (seat tube to handlebar stem) from my 19'' to this 17'' is 1cm.

With a smaller frame, you will need an appropriately longer handlebar stem in order to retain the cockpit length. This will affect handling of the bike: it will feel more "lively", which can be good in some cases (tight turns, difficult terrain) or bad (less stable) - in most cases.
A smaller frame will be marginally less reliable, and more prone to break, due to bigger stresses in its structure; longer stem and seat post mean bigger levers to exert force on the frame. But this should not be a significant effect.

As a rule of thumb, a 17" frame is an inch or two too small for your size. I would not recommend taking the smaller one without actually riding it for a couple of hours and making sure it's comfortable for you.


Using a new chain on worn out sprocket? I went to REI yesterday because my bottom bracket was creaking.  I brought my bike with me so I could get the right tools to take it off, but while I was there the mechanic actually took the crankshaft apart, cleaned, and lubed everything for me (I guess it was a slow day).  He also checked my chain with a little gauge and said that it's more than 100% worn.  He said that it is so worn out that my back set of sprockets could be damaged from it.

The mechanic said that I should replace my chain every 2000 miles.  I have been using my current one for about 3000.  Is 2000 miles a good distance to replace a chain?  (I've never had this problem on my mountain bike.  I always replace the chain every summer because of rusting.  I didn't even know that it could actually wear itself out.)

I went home and ordered this chain on eBay.  If I put it on my bike and my sprockets are indeed worn out will it wear out my new chain quickly?  How will I know if I should replace the back COG?

Thank you.

PS: The chain I ordered has a Titanium coating, does that mean it will last longer than a "normal" chain, or is it just advertising?  KMC says it can last "up to" 10k miles, is that true?  Does anyone have any opinions of KMC chains?

Also, this is my first road bike, and I don't know too much about them.  I got it for my birthday for commuting to school (and work in the summer).

If your chain was measured and is worn, then by all means replace it.  You are going to cause more wear to your bike using a worn chain than having slightly worn sprockets.  A worn chain causes uneven wear on the teeth of your chainrings and cassette cogs, eventually this can cause issues with shifting and 'chain suck'.

The new chain you selected looks good. Before you install it, please clean off any grease and grime from your front chainrings and cassettes.  It should be good without re-lubing for a couple hundred miles with the factory lube, after that you should make sure that you keep it clean and lubed regularly.

The life of your chain is proportional to how you maintain it, a good chain poorly maintained will last a couple thousand, well maintained I don't doubt it could last 10k.

More info on chains: http://sheldonbrown.com/chains.html


Are all 9 speed chains compatible with all 9 speed systems? My current chain is x9, but it's expensive in eBay. Can I use any 9 speed chain like on this page?

AFAIK any 9speed chain made for dérailleur should fit (single speed and hub gear chains are different)

9 speed chains are more expensive, they are thinner and not as common - so fewer cheap brands bother to make them, or stores to stock them

BUT - the chain is an important part of the bike, a poor quality chain will stick, jump and wear the rear cassette teeth more quickly. You might not want to buy the very cheapest brand you can find.


Should I switch to a smaller chain ring? I am back to cycling after 7 years absence due to injury and time commitments. When I started 3 months ago I weighed 20kg more (105 kg in total) than when I stopped. My target is to build fitness (100+ miles per week) and lose the weight gradually (1kg per month) both of which I currently reach.

My bike has a standard Shimano 105/5800 groupset with 53/39 chain rings and 11-32 cassette.

In the flats with a little wind from the back I tend to be in the largest gears whilst running at a decent cadence, but as soon as I start climbing more than 3% (and I live in a hilly area) I tend to be on the smallest of gears.

So my real question. Would it make sense for me to switch to the smaller 50/34 chain rings? Or is it more sensible to tough it out for now and expect that both the weight reduction and fitness improvement will get me into a more comfortable position relatively quickly.

If I were in your situation, I would definitely get a compact (50/34) crank.  Gaining lower gears for climbing makes some uphills possible and other uphills easier. All you have to give up is maybe some top speed on downhills. You're still able to ride those downhills, only you'll be going 55kph instead of 60kph.  Or increase your cadence.  In general I come across a lot of people who think they need huge gears because they somehow want to have a really low cadence.

Since you said you're riding for fitness and weight loss, I don't think that top speed is a priority for you -- you're not competing against others in a race.  It's much more important that you can handle hills and don't hurt your knees.

My top gear is 46/11 and I never find that to be a limitation.  A cadence of 120rpm is quite reasonable for a few minutes (few descents are really long) and 120rpm with a gear of 46/11 is approximately 65kph.  With a top gear of 50/11, it's 71kph.


Where can I get a new steer tube or 1 1/8" 6061 Aluminum Rod Stock? I have an Anti-Gravity fork that features a removable steer tube, but it is a threaded fork. Where can I buy a threadless steer tube to clamp into it to convert it? All I can find are threaded steer tubes or steer tubes pressed into a specific crown.

Here's a picture of the fork: http://www.retrobike.co.uk/forum/files/antigravity_fork_728.jpg . When viewed from the rear, by loosening two bolts I can remove the steer tube (it's already 1 1/8"). Do most forks not do this? Why aren't these more common?

This seems like it would work just fine: http://www.onlinemetals.com/merchant.cfm?pid=6997&step=4&showunits=inches&id=71&top_cat=60 , 1.125" OD, with 0.065" walls for a 0.995" ID would that be close enough to put the threadless cap inside?

Essentially, I'm looking for two things:

1) Where can I get the 1" ID 6061-T6 Aluminum, and

2) Why can't I find this by searching for 'threadless steerer tube'?

Here's a picture of my fork specifically.

2 things:

While many older forks used replaceable steerer tubes, the steerer tube is still specifically  shaped for that fork. Tubing will not do it. You need an oem replacement steerer tube. Nobody makes forks like that anymore, hence the lack of google results.

Also, that steerer tube in the photo looks to be steel, and should not be replaced with aluminum.


Is it possible to change a Shimano FC131 crankset's chainrings? I'm going to buy a bike wtih this crank, but I want to change the bigger ring. This is one of the lower end shimano cranks -- so I am worrying that the chainrings may not be replaceable.

Thanks

Guys now I'll be needing a DIY way to change the rings cuz those gears are wayyyyyy to low for me. I need something, what about pulling off the bolts or something?.....

No, you can't.

The lowest Shimano level crankset with replacable chainrings is in the Acera group.

In any case, most replacement chainrings cost about as much as a Tourney (or even Acera) crankset, so it doesn't make much sense to replace the chainrings on those anyway.

As mentioned in the answer to your other question, theres a very good chance your bike won't be able to clear a 48t ring if it was originally spec'd with a 42t ring.


Safety comparison, downhill mountain bike vs. downhill ski My twelve-year-old recently tried downhill mountain biking when we were in Lake Placid. He found it thrilling and would like to continue with this new sport now that we are back home. I am hesitant for him to practice this sport on a regular basis because of safety concerns. We allow

basketball (with mouth guard)
soccer (with shin guards)
swimming
tennis
cross country skiing
ice skating for fun

We do not allow games with a stick -- ice hockey, lacrosse. And we do not allow American football or downhill skiing.

I'd like to be reasonably consistent with our existing policy!

Where does downhill mountain bike riding (on an established track at a reputable ski center) fit, on the scale of things? He has asked for a full-face helmet and elbow and knee pads, because that's what he was given to use as part of the fee at Lake Placid.

I'd like to avoid fractures, of course, but I'd mainly like to avoid really serious injuries and things that might leave him with longlasting health problems such as a knee or back that is never the same again.

I'm not worried about scratches or bruises.

Responding to a comment:

  This can't be answered without knowing the risk-taking behavior of your kid.

He is a risk taker and has a diagnosed problem with sensory integration (motor planning).

However, I personally think the question I asked can be answered without this additional information.

Having done both, I'd say they are about equally dangerous with the edge going to downhill biking.

It's easier to gain momentum on a downhill bike and harder to properly lose it.  Additionally equipment failure is a bigger concern and generally more catastrophic.  Downhill biking in the winter pads the ground (like skiing) but, during all seasons, trees are an ever present danger.  Losing control and hitting an unmoving object at 30 mph will generally have a bad outcome.

As a parent myself, I expect I'll probably downhill bike with my children at some point. As long as they work on learning control at slower speeds first and learn how fast and hard to press their limits they'll probably be fine.  Most of the injuries I have seen downhill biking have been with younger kids trying to ride way above their ability level.  The group of older guys I ride with are rarely (if ever) injured.  We generally ride right at our ability level and maintain control.  That being said, none of us are ever going pro.

In your situation, if you are just trying to maintain consistency AND have already decided downhill skiing is out (based solely on risk) then I'd say you should probably exclude downhill biking as well.


Handlebar size options I was given few options to choose the handlebar size for my future road bike. The frame size is 60cm but for the handlebar I have these options:

40x90,40x100,42x100,42x110,44x110,44x120

I measured myself from shoulder to shoulder and it's 44cm, so there are only two options for me. The problem is that I don't know what the second number mean.

The bike is for daily use and some events/triathlons, but most of all is for daily use.

Assuming these are Drop handlebars, the second dimension would be reach or drop.

On the other hand, as you're buying a complete bike, not just bars, the second dimension is very likely to be stem length.


Do pros ride with 1X configuration on some courses? I'm looking at the first stage of the Tour of California, which is on a flat course (around Long Beach, USA).

Since there's no real dénivelé (french, "difference in height"), there is no need for a lot of gears.

So, do pro riders sometimes use 1X configuration on their bikes, either on criterium races or on flat courses, or on flat time trial courses?

Yes, they sometimes do (or at least announce/intend to), here are two examples:

  This is the 3T Strada that Aqua Blue Sport will ride in 2018, making
  the Irish-based squad the first pro cycling team to use a
  single-chainring drivetrain.

Source

  One ring to rule them all: Tony Martin's Canyon Speedmax 58x11-32 on
  the world champ's time trial rig

Source


What is the maximum input torque on Sturmey-Archer internally geared hubs? What is the maximum input torque that can be sustained by sturmey archers internally geared hubs.  The website is surprisingly short on info about this.

I'm specifically interested in the hybrid gearing hubs that allow fitting a 9 speed cassette onto a 3 speed IGH.  But I expect the internals of all the 3 speed hubs are the same. http://www.sturmey-archer.com/en/products/detail/cs-rf3-silver

The website mentions a maximum sprocket size of 34 teeth, but without the minimum chainring size that's rather meaningless.

Thanks

A pro cyclist putting out 1.4 kWatt at 60rpm at the starting sprint has a torque of almost 2000 lb-in or 222 N-m.

A recreational bicyclist may be normally only be capable of just 1/10th that but even an out of shape Clydesdale (heavy but strong rider) just getting off to a start on a hill may momentarily hit that level. If they weighed 200kg but jumped on the pedal and momentarily put 800 newtons of force on a 170mm crank, that’s 136 n-m, or still a lot of torque.

If I was an engineer, I’d want to make sure that my components could handle that level peak on an occasional basis. If you’re really worried, get a Rohloff as they’re really well designed.


Giant Terrago 26 inch, can i have disc brakes? Hi I have a 26inch Giant Terrago and i was just wondering if I can have disc brakes. I can on the forks but I don't know it I can on the back?

I have looked at other bikes but couldn't see the same as mine so just wondering if anyone can help me on this?

Short answer: No.  There are no caliper mounts on the rear triangle of the frame so you can't mount brake calipers there.

There are solutions that add mount points, but they're pretty bad idea and have never taken off.  Plus an adapter would probably cost more than a used bike with disks.

Most braking is done on the front wheel, so fitting a disk brake there will get you 90% of the improvements anyway.  You need a disk brake rotor, disk-compatible hub, a caliper, possibly a mounting adapter, a cable or hose, and a new brake lever.   Buying all that new could cost as much as a good lightly-used bike.

Your front wheel could have a disk brake - the fork has mount points on it for disk brakes.  However your wheel is not disk brake compatible so you need a new hub, which probably means a replacement wheel.  If you can salvage parts off another bike, then that's the only way to make it cost-effective.


Ebike brake lever cutoff switch / interrupt switch : How does it work? When pressing the brake lever on my ebike the bldc motor controller (aka ebike controller) 'cuts power' to the motor until the brake lever is released again/sensor is deactivated. I would love to know how that works/what happens.

I am wondering what causes the power to be 'cut off' when the sensor is triggered by pressing the brake lever.
My theory is that the power (5v +) to the throttle and pedal assist sensor are cut off when one of the brake sensors is activated, this in turn causes the user to be unable to 'apply throttle' .

Perhaps my theory is way off, do any of you know how this works? Does it differ per case/controller ? Or is the method (of cutting off the power when one of the brake sensors is activated) quite universal ?

The controller I'm using: https://a.aliexpress.com/e1R175D8X

My battery: 20s 72v 10parallel

Thank you very much for any input, it is greatly appreciated!

In your current set up, the electric brake lever sensor will protect against the situation where you're emergency braking but forgot to release the throttle.

The brake sensors override the throttle because there's basically no reason to power the motor while braking.

If your bike was configured to use a pedelec or pedal-assist mode, then the controller will detect when your cranks are turning, and the controller then instructs the motor what power levels to be putting out.  There's generally some lag, where you have to do some rotation of the cranks before the motor starts to power you.  At the other end, the same crank sensor will take a short time to decide you've stopped pedalling before it drops the motor assist.

Its conceivable that you may be braking hard, and have been riding at 60 RPM on the crank.  Your feet may turn another half rotation, and then the motor takes a "missing" half rotation to decide to cut the power.  That could be an entire second of time where your motor is powering you forward against the braking force, which is 7 metres at 25 km/h or about 2 car lengths.

The electric brake lever sensor should be telling the controller to STOP RIGHT NOW and override those other inputs.

Additionally, electric brake lever sensors can be used to activate secondary electric brakes and scavenge some power back into the battery.  Sometimes this simply uses the motor as a generator, and sometimes there are separate coils.

This is relatively rare on ebikes, though electric trail bikes may have this feature.

Side note - electric brakes aren't legal, and the bike still needs mechanical brakes to be on the road.


Replacing a chainring - what did I do wrong? TL;DR

I thought I could figure out repairs myself but clearly I'm a moron.

I replaced the chain and chainring on my fixie last Saturday, and this morning it got scary loose on me. I started to feel what felt like slack in the chain, but when I pulled over to check it out I noticed that all five of the bolts on the chainring were halfway to falling out.

From start to finish, here's everything that I did when removing the worn ring and putting the new one on:

Remove old chain (do not remove crankset from bottom bracket)
Starting with an Allen wrench and a screw driver, I started removing the nuts/bolts holding the old chainring in place. Successfully remove three of the five. Glare at rust on threads of nut.
Fight with the remaining two bolts, which seem to have seized. Add a small amount of WD-40 to seized bolts. Fight some more. Swear. Attempt to use a hammer to tap on screwdriver to loosen bolts. Lament my lack of a third arm. Swear some more.
Take a break. Look accusingly at old chainring. Pretend to do something else, in order to lull it in to a false sense of security.
Attack bolts without warning.
Realize that the only thing I'm doing is stripping the nuts and coming seriously close to accidentally stabbing myself with a screwdriver.
Admit defeat, go to LBS. Get a proper chainring nut wrench and a replacement set of chainring nuts/screws.
Cackling with the newly found power of using the proper tool, removing the frozen bolts and the old chainring.
Small amount of WD-40 on a rag used to clean rust transfer off of crankset, then wiped down with clean rag
New chainring in place, finger-tighten new bolts
In star pattern, use Allen wrench and chainring wrench to tighten bolts
Repeat above for good measure
One last time, just crank those suckers as tight as possible
Install new chain
Ride to/from work, no problems.
Ride to work, almost die, s#!t bricks.

All told, I rode about 20 miles between installing the new chainring and the extreme loosening that I had this morning. Did I miss some fundamental step in this process, or was this just bad luck? What can I do to keep this from happening in the future?

EDIT: Now with photos!

I only removed one of the bolts because I didn't have the time to take the whole thing apart. If necessary, I can disassemble the entire thing when I have time.

Also, man my bike is dirty. :-/

Outside of chainring

Inside of chainring

Outside after I removed a bolt

Inside after I removed a bolt

The bolt I removed

Consider that you should use either grease on the threads of your chainring bolts when installing chainring bolts, you want to be able to easily remove these later as chainrings do need to be replaced over time. Get some grease on the faces of the chainring and crank spider where they touch the chainring bolts. Some people are fine with blue loc-tite, but I prefer not to have to force it.

Don't just tighten them once and assume it's ok.  Go around the ring and tighten every other bolt until you've tightened them all. You can do a star pattern if you prefer, just don't tighten them simply in order around the ring.  Make a couple passes and incrementally increase tightness. You want to ensure they are tightened evenly, so that none of them are loose while others are over-tightened. Use a torque wrench if you're really worried about over-tighening.

Make sure you're using the appropriate length of chainring bolts (which doesn't seem like a problem from the photos).  Some bolts (actually the sleeve/nut) are made longer to go through the crank spider and 2 rings (or bash guard), while others are made shorter to go through the crank spider and a single ring.


Replace my stock crankset and cassette for a 22-32-42t crankset and a 11-40t cassette on recumbent trike? I am leaving on a coast to coast tour starting in Florida and ending in California this November.

I have a Catrike Expedition with a 30-39-52t Truvativ Elita and a 11-30t cassette with a 26" rear wheel. This gives me a granny gear of 24gi.

I want a super low granny gear. I never use the largest chainring as I do not like to go fast down hills, in fact I sometimes apply brakes if going too fast (over 20mph). I want a granny gear of less than 15gi and I know this is ridiculously low but I want it. Can it be done and work good?
I also have a chain gobbler for my boom. Will it help my situation any?

The issue here is going to be clearance between the frame and chain in the extreme gears. The smaller chainring moves the chain down towards the front crossmember, but from the images I've found online I don't think that will be a problem. The drop from 30T to 24T alone gives you a 19" bottom gear. In order for the rear derailleur to keep working you need to keep the gap between the biggest and smallest chainrings about the same, but you are planning on that anyway - right now 52-30=22T, you want 42-22=20T so that's fine.

At the back you have the issue that you need to clear the frame with the bigger cog, but you also have 10 extra teeth worth of chain involved. The jump where 11-30 becomes 11-40 might not work with your current derailleur, or might not allow you to use all possible gears. I suggest getting a 12-34 cassette instead, as the 11T cog wears out faster and the extra tooth will help you keep the rear derailleur happy. With 34T instead of 30T you get a slightly lower gear without going too far for the derailleur.

If you don't install extra chain, you probably won't be able to physically get into the 42-40 gear, and the drivetrain will wedge itself solid if you try. That can damage the trike, either snapping the rear derailleur off or bending it into the rear wheel.

But if you add the extra chain the opposite happens - in the 24-11 gear you have so much chain that the rear derailleur can't take it all, and you end up with chain dragging on the ground. If you run over the chain the rear wheel will stop and you'll slide along on the chain, wrecking a section of it.

Note that quite a few recumbent riders do this, because the gears where this is a problem are not really useful gears. It's generally better to have the extra chain, because you can shift back out of the bad gear and keep going, but if you wedge the drivetrain it can be annoying to fix even if you don't damage anything (often requiring you remove the rear wheel, or release the boom so you can slide it back and loosen the chain enough to free it).

You will also need a few tools do to this, specifically a chain breaker (and some extra chain links), a cassette removal tool, and some allen keys.

I suggest contacting Catrike first, as they will know exactly what you can do with the trike, and likely sell you the parts for about the same price as an online shop would. Then you can try taking the trike to a bike shop if you have one nearby, or start watching youtube videos showing people changing cranksets and cassettes. All the bike bits like gearing work the same on your trike as on a bike, they're just in different places. So all the instructions you'll find online should help, you just have to remember that "the bottom bracket" is actually out the front :)

Answers here like "is my chain too long" will give you ideas about how to work out the correct chain length after you've made changes. Some of the answers on "cross chaining" talk about why those gears don't matter (they duplicate other gears from different combinations of front and rear cogs).


Styles of Shoe Covers for Colder Weather After getting this pair of shoe covers,

I'm wondering whether this style of closure (zipper behind the foot) is reasonable.
I suspect that after the inevitable bit of walking on grass and asphalt, they'll be too mucky, and require ongoing cleaning.
The trouble, it seems, is that they must be put on after the shoes. These shoe cover only make sense for cleated shoes. One puts on the shoes, then pulls these shoe covers over the shoes, while adjusting the neoprene so that the cleats and the heels poke through the two openings at the bottom of the shoe covers.
Another style, one with velcro closure that wraps around the foot between the heel and the cleats, seems more sensible.
That style can be worn along with regular cycling clothes. The shoes are put on later, and then it's simply a matter of pulling the velcro shut.
Can you comment? I need these covers as a solution to feet getting too cold, and nearly numb, at just 12°C/54°F. I am looking for a solution that will enable riding until freezing (then I'll park during winter).
Related:
1,
2,
3.
So far I'm riding with synthetic base layers and wool (skiing) socks. I feel that switching to wool base layers and thicker wool socks will be all that's necessary to continue riding until freezing (with thin tires).
Update
It is a very small detail, but it may be worthwhile being aware of it, at least for some.
Style 1, (the one pictured: wear shoes; pull over; zip) requires having some bench next to one's bike. Putting them on without a bench or a seat is significantly more awkward than trying to wear socks without sitting down.

I have 2 sets of shoe covers, and each has its advantages.
One are very much like the ones you show.  These are much warmer and easier to walk around in, but take a little more work to pull on (they are tight to the shoes) and while water repellent they are not waterproof.  They are perfect for riding in cold, dry conditions (down to, say -5C with good socks).  I've never had a problem with the zippers.
The other pair are waterproof cordura-type nylon.  They are mostly open on the bottom, except where they hook over the toe, velcro up the back instead of having a zipper, and have a velcro flap that passes under the arch of the shoe to hold them in place.  They are not nearly as warm and mostly good in heavy rain.  (Although even then water will come up through the screw holes in the bottom of your shoe.)  These are easy to carry (they fold up smaller), and faster to put on, at the expense of being mildly awkward to walk in.
Durability is an issue with both of them.  Pulling the neoprene ones on and off over the cleat has mostly torn the strap under the foot, and the toe part (mine comes partly down over the toe) is mostly abraded away from stepping down.  I have gaffer tape one one of them to keep the toe from popping up off my shoe.  The cordura ones the velcro is not holding well any longer, and I've occasionally had the strap under the foot come loose.  (Fortunately it hasn't gotten caught in anything yet.)


Swapping parts from old bike to new frameset I have a Piave (around 2009-ish year) road bike with a frame that has become to small for me. It has pretty good components i.e Shimano Ultegra and threadless stem etc. There is a 2014 S-Works Venge frameset being sold and I was wondering, could I swap all my components (bar the fork, seatpost, BB, headset) Onto this new frame if I needed to? I have looked around to try find the sizes of things to make sure they fit but haven't found a lot. Any help?

Breaking it down:

Wheels, yes, if they are rim brake wheels onto a rim brake frame
Rear derailleur, yes
Chain, yes
Cranks, yes
Front derailleur, yes if yours is a braze-on type, otherwise new one needed
Brake calipers, yes (looking at the frame brake mounts here)
Shifters, yes
Saddle, yes

All of these parts have pretty standardised interfaces with the bike, which would explain why you haven't found much information.

Rim brake wheels have a 130mm spacing at the rear, while disc brake wheels are wider in the frame, or newer ones have thru-axles etc which are different again. If both frames are rim brakes then all is well.

You've correctly identified that bottom bracket, seat post and headset are most likely not compatible, as these components are a bridge between the specifics of the frame and the parts which get attached to it. The 2014 Venge has a narrow OSBB bottom bracket, an aero profile seat post and headset with 1-1/8" upper and 1-3/8" lower bearings.

You may need new handlebars and stem if these are not included with the Venge frameset, depending on the compatibility of your current set, or if you want a more integrated, aero style set to compliment the Venge frame. See our headset explainer if applicable.


Pressure range conflict between tire and rim I just mounted a new Ardnet Race tire that has a side label pressure rating of 35 - 60 psi .  The Stans Arch Ex rim that is mounted to says max pressure is 38 lbs, there is a little range on the sticker depending on the tire size, but this if to the mounted 29" x 2.2" tire.

The suggested ranges says I only have 3 psi to play with, 35-38 psi.  I used to run about 25-28 psi with the former Schwalbe Nobby Nics.  Why is the minimum rated pressure so high on these tires?

The answer from Maxxis support is about what I expected.  I am impressed that they responded and withing about a day.

Maxxis Support Team:

  The suggested pressure range is 30-60psi for most applications but you may find
  your particular setup to be different. Rim internal width, rider weight, and
  riding style determine the correct pressure. I would experiment with different
  pressures to achieve the tire characteristics that work for you.

I rode the tire at about 28 psi this weekend and it felt good.  Old tire still had tread but was hemorrhaging Stan's from the sidewalls and I could not longer keep up with it.


Using cyclocross tires for winter riding I've currently got a fixie road bike with some stock road tires. They're fairly low-profile, as in, they aren't knobby, and have low-profile treads.

Because my fork and stays have enough clearance for it, I'm debating using some CX tires at least early in the winter, before riding becomes nigh impossible altogether.

The two biggest environmental hazards I'd be trying to work around would be the cold (I want to try and stay on the bike down to about -10 or -15 ºC) and slush, which is extremely abundant where I am even fairly early on in the season.

I'm not looking to avoid ice; at that point I'll probably look for another means of transportation.

Are CX tires generally alright for winter riding? What road conditions would limit their effectiveness?

Considering that you will be hanging up your bike come ICE time... I would say that CX tires can/would be a bit more confidence inspiring that a typical slick tire.  However, I don't think that a CX tire would be much better (and likely more expensive) than a nice inverted tread commuting tire like the continental Touring Plus or an equivalent.

Having commuted in an area like you describe... cold wet, more slush than snow, etc... I have had very good luck with inverted tread commuting tires and they can be (are) usually a bit more pleasant on pavement than CX tires.


Why ride a single-speed bike? A question came up recently about why people ride fixed-gear bikes. I think you can't reasonably answer that question without first understanding why people ride single-speed bikes.

So, why do they do it?

I ride a single-speed (as opposed to fixed gear) because I like to be able to coast down a hill without worrying about spinning out, or hitting a pot-hole while frantically trying to keep up with my pedals. Don't get me wrong, I love riding fixed-gear, but for where I live it's just a little impractical to not be able to coast.

I ride a single-speed (as opposed to a geared bike) for multiple reasons.

A: It's all I could afford. If you only have $600, you'll get a lot more bike with a single-speed than a geared bike.  Or rather, you'll get a lighter bike with better hubs/wheels/etc than for a $600 geared bike. Someday I'll have the money for a decent road bike (105/Rival or better) and will buy one. But for now, my single-speed is much lighter and sturdier than any $600 geared road bike I could have gotten.

B: I enjoy the simplicity. Want to go faster? Pedal faster.

C: I enjoy the workout. I live in Utah, where there are some pretty big hills/mountains. The only way to get to the top is to (as my dad used to say) hunker down and gut it out. There's something quite invigorating about knowing you conquered that hill with the power in your legs instead of the mechanical advantage of your gear ratio.

D: Even on the freewheel side of my hub, my single-speed is quiet. No gears means that unless I'm coasting, my bike is nearly silent.


Replacement for Shimano Nexus 7 outer casing holder I swapped my Nexus 7 sprocket with a new and the bracket apparently has a much larger diameter, so my cable is not stopped. The drawings that came along showed that I need an "outer casing holder" like http://www.sjscycles.co.uk/shimano-alfine-sl-s700-outer-casing-holder-unit-6tv-9806-prod32968/

Do you guys know of a work around? Or should I just go ahead and order it?

If you've got the CJNX40 or CJ8S40 bracket then you'll need the piece. So yeah, order it.

Frankly, if you just swapped the cog I don't understand why the cassette joint is different. But I'm assuming more happened than just the cog. Whatever the case, if the casing slot/area/thing on this bracket is bigger than the previous casing slot/area/thing then that holder unit makes up the difference.


Is there such a thing as frame failure? Several general questions have been asked regarding how long a bike or bike frame will "last", and the gist of answers seems to be that a bike can last quite a while if the replaceable components are replaced and the bike is reasonably well maintained.

But what about the inherent structural integrity of the frame itself? Is there such a thing as a risk of sudden frame failure or disintegration after some level of use? Do bikes ever fall apart, or develop a risk of breaking or fracturing along weak points? One of my bikes has more miles on it than the car I'm turning in — and I wonder about the integrity of the car!

Yes, frames do fail even if they're not crashed or ridden excessively harshly. The only way to mitigate this problem is to inspect the frame regularly during your maintenance and cleaning. Look for cracks. When riding, pay attention to creaks and squeeks and always find the root cause (it could be a crack).

Keep in mind that:

A bad weld could hold fine for years before coming apart.
Unchecked rust can eat through steel tubes, either from the outside-in or the inside-out. Once it starts, you have to keep on top of it or it will eventually take the frame. Rust also seems to have "good taste" in tubing by preferring the pretty Italian stuff to, say, gas-pipe schwinn.
Metal fatigue can form cracks that grow slowly until the frame suddenly snaps (I've seen this personally where the chainstay meets the dropout, and on crank arms).

Aluminum is the worst culprit for fatigue cracks. Aluminum seatposts and steerer tubes also have a tendency to develop aluminum oxide blooms that may permanently jam the seatube/steerer-tube in the frame.

Carbon typically won't survive a bad-enough crash. I've heard of long-term delamination issues, but never saw one personally. AFAIK every carbon frame "dies" in a crash or mishap that damages the frame to the point where the owner no longer trusts it. Anyone have stories about what happens to carbon that is not crashed?

For a concrete example, below is my own failure from a few years ago. It happened as I was cresting a very steep hill. I heard a loud "pop" and didn't realize what happened until I looked around and saw the chainstay separate from the dropout with each pedal stroke. This is a steel bike and was totally repairable, BTW. I didn't crash as a result (but neither was I going fast). Note the little bit of rust visible at the top of the crack. It indicates that the crack had been there for some time before the total failure.


How can I learn to sprint and ride out of the saddle? I'm pretty new to road cycling, I've been road cycling since June 2017, because it's winter in Canada I recently got a indoor trainer and zwift. On a recent zwift session, I tried sprinting out of the saddle and it felt very weird and my watts as well as my speed were way below what I can do while in the saddle. Any tips on how I can get more comfortable sprinting and in general riding out of the saddle? Thanks!

If you want to improve balance and control out of the saddle at any speed, even freewheeling, you just have to practice doing it.  Note that balance while pedaling out of the saddle on a trainer vs. on the road will be very different as the bike is held firmly upright in the trainer

With respect to power output: pedaling out of the saddle is usually done for a short burst of power against a high resistance with a low cadence - either up a short steep slope or accelerating in a too high gear. Pedaling at a sitting cadence while standing up will be quite inefficient.

Basically, you have to get the gear ratio selection right to enable max power output. Lower for in the saddle, higher for out of the saddle.

Edit:

You might want to experiment with how forward or back over the bottom bracket you position yourself when out of the saddle. You may find you can find a more comfortable position that works better for you.


Cannondale super v 700 with a bad Headshock This is my 3rd headshock that has gone bad..I was told to replace it with a new fork rather than try to fix it.  I need help picking out a new fork that's not too expensive or tell me how to fix the one I have.

How do I determine if a new fork is compatible with my bike?

There are companies which service forks (like the Shock Treatment Center at QBP). Chances are your local bike shop has an account with QBP and might be able to arrange something to get it fixed, provided QBP services Headshok forks (if not, another non-Cannondale company might). Of course, the reason why your fork went bad may have something to do with servicing it / preventing it from going bad further, and given how old this bike is, they might (probably) won't service this fork. But you might find a different company that does service old Headshok forks.

As for replacing a Headshok (or Lefty for that matter, I think), you'll need a Problem Solvers Headtube Reducer for Headshok forks which will convert Headshok to 1 1/8". You can read the instructions, but basically, you pull out the Headshok, remove the bearings, press in the reducer and then install your headset and fork. Other manufacturers also make parts for converting from Headshok to 1 1/8" (e.g. Cane Creek's Double Xc).

You'll need a shop to install the Problem Solvers reducer (or other manufacturer's options), since it requires a bearing press (which home mechanics don't have; its about a 150 dollar tool that you will probably use once in your life). So, while they're at it, they should be able to set you up with a compatible fork (by measuring axle to crown and what your other needs are) and everything else.

All that being said, this bike is close to 20 years old (maybe a bit more, maybe a bit less) -- the parts you need and labor will likely make it more favorable to buy a different bike; before the fork, you may be spending 50-100 bucks on the parts to get a standard fork to fit in the first place. I'd probably bet that a basic hard tail today would be better across the board than a 20 year old full suspension bike, too.


What are the advantages (or dis-) of the GT triple triangle frame? Like this one, for example.  Is there any plus or minus to this frame design?

(I'm shopping for an 80s/90s steel frame bike and the GTs may be a possibility.  It turns out I kinda like a horizontal top bar for the look of forward motion that to me a compact frame doesn't have.)

A significant drawback I've found (I've got one of their hybrids) is reduced options for mounting things:

My toddler seat has to go lower than it otherwise would, making it much harder to fit panniers underneath.
I can't fit a triangular tool bag there
It makes fitting a D-lock mount inside the triangle harder

(obviously these 3 are pretty much mutually exclusive anyway)

Also it makes shouldering the bike harder -- your shoulder is further forward meaning the bike isn't as well balanced.


Compatible crankset - Giant Iguana My gears started slipping on my Giant Iguana Disc (probably neglected chain) so I've changed chain and cassette. Wanted to change crankset so I've bought a Shimano FC-M311 but found that those 4 teeth in the picture touch with the dérailleur attached to the frame. I'm trying to figure out what crankset to buy but have no clue and can't figure out how to find one!

You have a couple options, but both require new parts.

1) Buy a clamp-on front derailer. Currently it sounds like you have an E-type derailer that mounts between the frame and the bottom bracket cup. Your bike ought to be able to take a standard clamp-on derailer that mounts above the bottom bracket, well away from that part of the crank.

2) Replace your bottom bracket with a longer spindle. This will move the crankset outwards, hopefully clearing the derailer bracket.

Of these two, the easiest and best solution is probably 1. If you want to really do this on the cheap, you could grind away those tabs - they aren't necessary for the function of the crank at all (as far as I'm aware!).


please help me identify this bike, it is a haro bmx frame and i have the serial number The serial number on my haro frame is RVW1K00270. it is a bmx frame, i wanted to try find out which model and year is it please?

it should be a 2001-ish Revo because it starts with RV. This website may help:

http://bmxmuseum.com/forums/viewtopic.php?id=206889


Should I ride my bike on the beach? This is the suggested follow up question from this earlier question that dealt with if I can bike on the beach.
While it turns out I can ride the beach on 32c tires, the comments made it clear that I should take other things into account.
So, should I ride on the beach? What are the pitfalls I should be aware of? And what advantages are there over staying on the road?

Sand + Saltwater and unsealed bearings are not a good mix.
Some things to consider depending on the value of your bike and cost for replacement parts are:

Upgrading your bottom bracket to a sealed bearing. Sure there is some frictional loss there but even road cyclist use it on training bikes for bad weather riding

Upgrade wheel bearings to sealed bearings/rebuild them more frequently

I assume your bike is either aluminum or carbon not steel. If it is steel washing it to prevent corrosion from salt would be a must and touching up paint chips to protect the steel is a must too.

Clean braking surfaces after each ride whether rim or disc brakes to avoid sand wearing them out prematurely.

Use a proper lube on the chain and clean your chain frequently. I personally would use a wet lube, but if you consistently find yourself in powder sand, then perhaps a dry lube would work and avoid having sand stick to it. However, I have found that dry lubes tend to lose their functionality even after 1 splash from a puddle so chose carefully there. Some suggested lubes that I have used (WD40 Wet Bike Lube and Finish Line Ceramic). I find 100 - 200 mile chain cleans work well for me on road conditions. If I rode on the beach and had a lot of sand stuck to the chain, I might service the chain more often like after each long ride, etc. Here is a link to a typical chain clean service -


One of the cogs on my freewheel is bent and I have an assumption of how it happened I was riding up a steep road when I shifted to a lower gear and I was pushing really hard on the pedals. Then I checked my freewheel, one the cogs was slightly bent I don't know if it got bent because of that or it was like that from the start (used bike but new). so can pushing hard while shifting bend the teeth or a cog on a freewheel?

So the damage happened at the same time you shifted to a lower gear ?  I'm guessing you were pushing hard because its a steep grade, and the chain was not fully engaged in the bigger cog when you pushed hard.
 Notice the top 6 teeth are not engaged on the biggest sprocket, but are also not meshing with the next-smallest sprocket?
Image shows a 28 and 32 tooth, so this could be exacerbated by a larger tooth difference, like it the final cog is a "megadrive" than can be a 10 tooth difference from the next cog.
 Trying to show a view from the rear - the chain veers to the right-hand side at about the 11 oclock position.  Both photos are the same chain lay.
So this chain lay, combined with

a lot of leg power because you're going up a hill
probably the rider is out of the saddle and leaning forwards for more power,
a smaller front chainring working to multiply the leverage
a chain that has no particular weak spots

could twist a part of a cog.  And it would look like a twist too.  The other option is a fold, which would have some other kind of cause.

Also, what "groupset" or level is the cassette?  If its non-groupset shimano, or some pot-metal quality cheese-grade steel cog then that increases the likelyhood it failed.
As for fixing it, you may be able to straighten the cog.  Likely its all secured together into one block so you're working around the other parts.  Be aware that if you do get it straight, the metal will be permanently weakened and more likely to do this again.
The best option is to replace the damaged freewheel, which can be galling if there's significant life left in it.


Shimano Nexus 8 speed gear hubs: Difference between SG-C6000-8D and SG-C6001-8D? I'd like to build a wheel with an eight-speed Shimano Nexus gear hub with disk brakes.
Does someone know the difference between the SG-C6000-8D and the SG-C6001-8D?
For both, Sheldon Brown says "Three roller clutches, Band brake (? -- none shown in exploded drawing)/brakeless."
Thank you.

Sheldon Brown died in 2008; C6000 came out in 2014, so you won't be getting His wisdom on that site in relation to these.
2014: https://productinfo.shimano.com/download/?path=pdfs/archive/2014-2015_Specifications_v020_en.pdf
gives 6010 (high efficiency) - 8R (roller brake) & 8V (v-brake)
also 6000 (standard efficiency) - 8R, 8V, 8C (coaster-brake)
2015 spec adds -8D (center lock disc) & 8CD (coaster brake with special five-bolt disc)
2016 spec adds 1, i.e. 6010 becomes 6011. And 6010 is deleted.
If one refers to any of the -11 or -01 diagrams, the changes are clear:
https://si.shimano.com/api/publish/storage/pdf/en/ev/SG-C6011-8R-8V/EV-SG-C6011-8R-8V-4040.pdf
https://si.shimano.com/api/publish/storage/pdf/en/ev/SG-C6001-8D/EV-SG-C6001-8D-4131B.pdf
Y3EH98040 vs Y36V98030 Carrier Unit (01)
and
Y3EG98030 vs Y36W98030 (11)
the other change is hub axle unit
Y3EK98020 vs Y37N98020 (01)
Y3EH98050 vs Y37L98030 (11)
i.e. the hub axle unit & carrier unit were both changed because they were deficient in some way
Carrier unit is similar to this

Axle unit is similar to this
http://rideyourbike.com/shimanoaxleunit.shtml
The same parts were also updated on Di2 and Alfine
https://si.shimano.com/api/publish/storage/pdf/en/ev/SG-C6061-8C/EV-SG-C6061-8C-4039.pdf
https://forum.cyclinguk.org/viewtopic.php?t=64432&start=630#p1267269
So basically you can use either hub, but C6001 should be an improved version.


Giant Cypress Upgrade I have very little knowledge when it comes to bicycles and how they work. With that being said, I have a Giant Cypress Hybrid. It is a great bike for the most part. I'm looking to get a little more top end speed out of it. When I'm on a paved trail, its simply nkt fast enough for me. Another gear or two would be great. Is it possible to just replace the rear cassette,  or do you have to do something to the front as well?

What others are saying is right.  If you have a 48/11 and are only going 20 mph (32 km/h) then you aren't spinning fast enough. You also won't be able to find a cassette with smaller than an 11 tooth cog.  You'll have to get bigger chain rings.  That being said, it might be difficult to spin fast on a hybrid with platform pedals. Personally I find it easier to spin fast when I have clipless pedals. Also, make sure the bike is fit correctly to your body. If your seat isn't high enough and your legs are bent too much, it can be hard to get a high cadence.


Campagnolo Ultrashift, Escape, Powershift Identification Can anyone help identify if this generation of Campagnolo Chorus 10 speed alloy-only is ultrashift, escape, powershift, etc? I've done a bit of googling, but without much more knowledge on the parts, I can't be sure! I'm asking because I need to order new cabling for the group and want to make sure I get the right cables :)

They look exactly like these:

They're second generation Ergopowers. I don't know the name for the mechanism, or even if there is one, but it seems similar to current UltraShift. For original spare part codes, look up Chorus 10S in spare parts catalog. Looks like UltraShift cables have the same dimensions.

I have been using third party Campagnolo-compatible wires and Shimano outer cables with success, the original ones didn't seem to like low temperatures.


What type of bicycle would be the most suitable for riding in winter in the city? Say you have any type of bike available (BMX, Trial, MTB, etc.) and you can ride them all on the same level, just for the sake of the argument. What bicycle would be best to choose to ride in the city (short distances, traffic, people) in a very bad winter condition (snow, ice, etc) and why would you make such a decision?

UPDATE

I'm asking this question because I have both a BMX and an MTB bike available and since I plan on riding a lot during the winter, I could go as far as buying another type of bike especially for that purpose. Both my BMX and MTB bikes are newly bought 2011 models, so they have all the today's features of a standard bike.

I've commuted through two winters in the Pacific Northwest and I have learned how to be prepared for winter wet, snow and ice. In general, my advice:

fenders...or love your mud stripe, in fact, I extend my fenders with panels cut from milk jugs
ziplock pogies if you need them
glasses (keeps the rain out of your eyes, and car splash too)
a full sized bike with a rack really helps because you have a place to put your layers or a change of clothes
if you expect ice, which loves to live on shady, unplowed residential streets, a pair of studded tires is a wise investment (I have a pair of Schwalbe Marathon Winters)
lights: winter commuting puts me on the road before sunrise and after sunset, I need to be visible
your patch kit and pump: I have had more flats in wet weather because wet rubber cuts far more easily than dry rubber. Sharp gravel, nails, beer bottles, whatever it is, I'm more likely to get a flat in wet weather.

I have not found that tire size, or tire tread has made significant difference to me, I have learned you cannot ride on a snowy shoulder, you want to ride on the least snow or ice possible, otherwise you might just slide into the gully. Studs don't help with snow, deep tread might. For plain old wet weather, I have had no trouble with road tires, I didn't get any advantage from knobbies, in fact I replaced my MTB tires with road tires.

Good luck with your commute!


Is Back-pedalling normal ? chain keeps jumping from higher to lower cog in rear cassette I just bought a new bike Marin Pine mountain-1 which has 1 X 11 drivetrain. I want to know is Back peddling normal ? I called my mechanic and he said you should not do back peddling or this will happen.
when I do that it suddenly starts shifting the chain to lower cogs.
I am not sure why ? chain and everything is just 1 week old.

This is typical-ish behavior, especially if your derailleur gets a bit out of adjustment/alignment, the chainline not being quite right, etc.

You shouldn't really be backpedaling significantly, just to move the pedals into the right place (e.g. cornering, starting to ride, etc.). So, this isn't really a problem in real riding. If its happening when you're just moving the pedals (which is about a half turn of the crankset, normally, like getting the pedal up to start riding), then take it back to the shop and get them to check the adjustment of the derailleur.


Brake pads destroying wheels Today I braked my bicycle from 50 km/h with my front rim brake and  heard a really nasty sound coming from the braking surface of the wheel, and I saw some metal shavings as well.
The brake has been randomly making these noises for a little while, but this is the first time I've seen shavings.  The brake pads and rims are about two months old.

Do you think my wheel is toasted or my brake pads are too hard?

I have rim brakes. It has been happening for a while, randomly but just the sound, never seen the metal shavings flying from my rim. And yeah, the brake shoes are like 2 months old, as well as the rim.

The rim is aluminium.

Sparks coming from rim brakes sounds like there's some hard object, such as a piece of grit or metal, embedded in your brake blocks. After two months, they shouldn't be badly worn, unless they're very soft, but pads will eventually wear enough that the metal cartridge mount is now touching the brake track.

You should check your rim for damage. If it looks badly scratched up, it might be damaged. Also, hold a steel ruler or other straight edge radially against the rim.  A new rim should be almost straight; worn rims develop a concave profile as braking erodes the material.  (By the way, if there's one perfect groove right around the rim on both sides, which looks like it was cut by a machine, that's a wear indicator: as long as you can clearly see that groove, the rim's not overly worn, assuming it's in good general condition.)

My guess would be that the sparks were from something getting lodged in the brake pad and the noise before that was due to poor adjustment.  Brake pads need to be "toed in" slightly so that the front end of each pad touches the rim slightly before the rear end. If the rear end touches first, the brakes judder and vibrate.

If you're not confident that you can diagnose this problem yourself after getting help here, you should get the bike checked out by a bike shop. The front brake and front wheel are critical to your safety.


Can anyone help me identify my bike please? Can anyone help me identify my bike please? It has a slight story attached as it was one of the bikes in the new Lance Armstrong film. It was badged up as a Gazelle TVM (and as far as I can see, re-sprayed to represent the team colours). Most of the transfers were removed before re-sale but two remain. I'm fairly sure it isn't a Gazelle, after checking their catalogues from the 80s and 90s.
At both ends of the top tube it has heart cut-outs on the lugs and also at the top of the down tube. The brake cable also runs externally, under the top tube and has three stays, evenly spaced out. There is a serial number on the bottom bracket which reads; 90250 and also says 54 degrees (o) C. I've searched for this but come up with nothing. I suspect the frame is Columbus and the bottom bracket is about 76mm in width.
Does anyone have any ideas? The bike is great to ride, so I have no issues with it. Just curious if anyone knows what it actually is??
Cheers[full bike

The heart cutout is De Rosa logo. You can probably find out the exact model by matching lug styles and which lugs have the cutouts.

The link from other answer mentions that there were De Rosas among the bikes used in the film.


Can anyone suggest a way to mount my rack to prevent it impeding the rear brake? I have a topeak rear rack the mounting of which is interfering with the operation of the rear brake.

Unfortunately, my frame (a 2009 Scott Sportster P4) only has mounting lugs on the outside of the seatstay meaning that the rack's mounting arms just touch the outside of metal sheath around the brake cable. The brakes still apply but the cable is not free to move as it should be. A pretty standard V-brake setup.

Does anyone have any good ideas for a mounting solution that would enable me to mount the rack in such a way that the mounting arms bend in more quickly to avoid the brakes?

I'm tempted to heat up the arms and bend them with a wrench - any concerns or recommendations?

You shouldn't even need to heat up the arms.  Just bend them whichever way you'd like; it's easiest if you have access to a vice.  You might even look at having them make an 'X', if that pulls the mounting arm away from the brake.   By design, the horizontal stays should have a minimum amount of force on them - they handle keeping the rack from rotating forward and aft while the bulk of the weight is transmitted down the vertical stays.

You could also get p-clamps and attach the rack stays lower or higher as needed to clear the brake.


Spacer for non-drive side dropout My bike has a hanger like this:

Since the nut acts as a spacer between the end of the dropout and the hub, it's quite hard to center the wheel. What kind of spacer/accessory can be mounted on the other side so that you can just pull the wheel and it would be aligned when it hits the spacer and the hanger? The dropouts don't have adjustment screws.

There are spacers that are sort of in the vein of what you describe. They look like this:

However, these are intended to be used as a matched set and aren't adjustable, so using just one of them probably wouldn't just do what you're wanting here. You could probaby file one down to make it do that, however.

Another thing to bear in mind here is that it's actually very common, especially in the bike boom era, for manufacturers to use the horizontal dropouts of their frames to give themselves room to be a little sloppy with the symmetry of the left and right chainstay/dropout assemblies. As long as the paths of the axle slots are parallel, having the start and end points be off by a few mm doesn't matter much. In other words there are a lot of horizontal dropout bikes where if, say, you pulled the axle all the way back in the dropouts on each side, the wheel would be off-center in the frame, and where using spacers like the pictured ones wouldn't work unless you nudged one ahead of the other the right amount.


Does covering 21-23km per day as a beginner hurt your knees? I’m 29 years old and I have bought a hybrid bike 5 days back. I’m a beginner in this field and last time when I rode a bike was 15 years back. From last 5 days I’m covering 21 to 23km in approx 1 hour and 15 minutes with an elevation of around 250-300m. I want to ask that can it hurt my knees if i ride daily with this same scenario or I will get use to of it? Please note that i’m coming in this field straight out of couch.

Secondly, I’m 5’8” and I’m riding 17 inches bike. Is it perfect for my height?

If you are going from a level of inactivity to  21 to 23km a day, yes, you may experience some aches and pains. As you get fitter and more used to the activity these issues may go away. If issues persist see a doctor.

Something you should do is check your saddle height and fore-aft position.

A commonly used 'rule of thumb' for setting saddle seat height is to sit on the bike wearing the shoes you ride in, put your heel on the pedal, you leg should be just straight.

For setting saddle fore-aft position, sitting on the bike with the cranks flat, foot on the pedal in normal position, your kneecap should be vertically above the pedal axle.


How to lubricate a bicycle cable so I'm very new to all this, so I don't know a lot. My mountain bike will no longer shift gears, I've been told this is because my cables need lubricated, but I have no idea how to do this, so, how would I do that with a spray lubricant?

And please keep in mind, I don't really know anything about bikes.

It is always strongly recommended (by the manufacturers, I read it on Shimano's instruction sheet) not to lubricate a new cable when you're installing it. The reason is that both cable and housing are teflon-coated at the factory and lubrication could destroy that. When a cable loses the ability to move freely it is best replaced together with the housing.


Frozen Fork on 2011 Diamondback MTB I have a frozen fork on a 2011 Diamondback Response MTB. It worked fine when I purchased it back then and was riding it regularly. It has sat in storage for the past 5 years and is now frozen. Can I still use it or should I purchase a new fork?

According to Performance, your fork is a  "SR Suntour XCT with 100mm travel, 28.6mm stanchions".

These aren't really forks designed to be serviced -- they're basically the bare minimum of forks which are not completely for fashion statements. You can look on Youtube for videos of people trying to service them and what not -- you're basically going to strip it down as much as possible (which may require some penetrating oil), grease it up, and put it back together (you might get a head start on this by banging it a bit to see if it unsticks). Note that this is  maybe a 50 dollar fork, and depending on how much you value your time, you might want to take it into a shop to see if they can unstick it or just replace it, possibly with a rigid fork if you're trying to save money.


Why are post ~'80s bike finishes so "dull"? It seems that (with some notable exceptions) bikes from about the '80s and earlier seem to have more pleasing finishes than later bikes-- is there a verifiable reason for this, either economically or technologically?

There are many older bikes in price ranges low to high which have very nice finishes, whereas it seems all modern bikes more or less look "cheap", gaudy or just dull: E.g. it seems that nearly all the bikes on Trek's site are bright red or have neon accents if they are not some shade of black/white/pewter/silver. Now, apparently some other people do find Treks to be ugly but some also say they make some pretty ones too, so a pure "pretty vs. ugly" comparison isn't so useful.

Case study: Bianchi

In order to try to make the contrast as clear as possible, I tried to remove as many confounding factors as possible. Unfortunately, there are very few bike models made now which have truly been in production for decades without being significantly changed. However, there is one manufacturer which is famous for its finishes --- Bianchi:

Old (1935 Bianchi Corsa)

On this old road bike, Bianchi's famous "celeste" color has a pastel-ish hue and a metallic luster.

New (2015 Bianchi Specialissima)

Here, on a bike made nearly a century after the one above, the "celeste" seems to be slightly darker and also seems to have a soft-matte finish (however, the lighting in the photo makes it hard to determine). Now, of course, the exact shade of "celeste" has changed over the years. However, the luster of the finish is also noticeably different --- whether it was a deliberate change or not.

Conclusion

Despite the difficulties in finding absolute traits to contrast, what I have noticed is that many modern bikes have either the soft matte/satin finish seen above or a blindingly-high-gloss finish, whereas I've never seen these finishes on older bikes (not that all matte and/or glossy bikes are necessarily ugly). Likewise, very few modern bikes have the sort of "bright, light metallic" luster seen in a lot of older bikes: The closest I've seen is probably that of the Genesis Croix de Fer 10, but its finish still seems somehow "shallower" than those of older bikes. So, the question is: What changed between now and then?

This is not a complete answer, but one factor certainly is that nowadays bikes often use powder coating as their finish, rather than liquid paint.

Powder coating has signifcant advantages over paint (more resilient coating, no risk of running, no solvents required), but the surface characteristics are different. In particular, the sparkle effect of metallic paint can not (easily) be achieved with powder coating, and I believe multi-coloured finishes are also more difficult.

So check whether the new bike has a powder coating - that may explain the difference in apperance.


Comparing gear ratios on different bike types How can I compare gear ratios on different wheel sizes? How can I compare gear ratios on MTB with tracking bikes with bigger wheels? How can I compare gear ratios with gear hubs?

Typically you quote gear sizes in gear inches, very basically this is the drive wheel diameter multiplied by the ratio between the two gear cogs, traditionally quoted in inches.

Also sometimes mentioned is development which is the amount of distance travelled by one revolution of the cranks (the astute will notice that is going to be proportional to gear inches and possibly a more meaningful quantity).

The more complex alternative, but one which is an absolute number, rather than measured in distance is Sheldon Brown's gain ratio  which tries to include the crank length in the equation to get some sort of appreciation for the extra work for the smaller cranks found on, e.g., road bikes in comparison to ATBs. So for every unit travelled by the pedal on its circular journey, the bike will travel x units along the ground.

Hubs will still have an absolute number of sprockets, even if it is just an equivalence to a real cog so can still contribute to these equations.


Re-learning how to corner aggressively at speed after bad experiences I'm not quite sure if this should somehow be broken up into two questions, but what can one do to take sharp corners at speed effectively, especially when you're nervous after having bad experiences riding?
I'm already familiar with common techniques for high-speed cornering on a theoretical level (cf. a video from the Global Cycling Network), but I was never really good at taking corners hard. Now, however, after being in an accident with a car and afterwards having only ridden a lot in miserable conditions (snow, ice, sand/gravel on the road because of the snow, etc.), I realize that I simply don't do sharp turns... and trying to force myself to do it makes me extremely nervous.
Possible aggravating factors

Ill-suited bike: Perhaps it's the one rideable bike I've currently got? — it's a lot lighter and "tighter" than my previous training bike, which makes it seem fun to ride, but it just feels squirrely... yet that could simply be me not used to it.
Interference from similar sports: Between the accident and the winter, I was on a motorbike quite a lot, and I feel much more confident on it than I do on a bicycle despite going over twice as fast. However, the thing weighs 220kg as opposed to maybe 13kg, and you hug a motorbike in a way you don't/can't on a pushbike. Also, when cornering on a motorbike, it's completely normal to use the rear brake to control your speed; I find I'm instinctively trying to do this on a pushbike but it just makes me feel weird, and I don't even know if you can do this safely on a bike, anyway

Are there no "baby steps" I can try to do in order to get myself to corner properly and aggressively and yet to trust myself/my bike at the same time?

I'm only posting this as an answer because it seemed long to comment.

But i would run some drills maybe once a week or whenever your free time allows. Go to a sports store and get some little multi sport cones, or use beer cans or toilet paper rolls or what ever else you have that won't hurt you or the bike if you run it over or fall on it.

Two drills that may help is a large slalom where you need to tightly weave back and forth. The other being a large circle.

Start with ample room where it is almost too easy, then as your confidence and speed increases, decrease the size of the shape or row, there by increasing the angle and lean that you need to use.

You could even go as far to set up a small sprint course either in grass or a parking lot depending on how you feel, and start tracking you time. That way your not racing anyone but yourself and your own head.

It may take awhile to build confidence but repetition is key, after a while that fear should slowly start to shrink. Likely you have some degree of PTSD from the event, some may think it's silly but its very real. I was in a head on 60mph collision (in a car not a bike) about 6 months ago, and unfortunately have to drive on that same 2 lane strip everyday to work, and still i get anxiety going through there, it's a 2 lane underpass, old road so it's narrow, with guard rails on either side so there is no where to go. Guy came into our lane and there was nothing we could do but wait to get hit. Point is, it gets better it just takes time and repetition.

I have also found it helped my cornering a lot to concentrate on my position relative to the bottom bracket, sounds goofy but consciously being aware of my bad form and working on it with similar drills helped me gain a lot of confidence, i had similar issues when i switch from a 2.35" mountain bike to a road bike, just didn't feel right.


Can your rims wear down from too much braking? I have a question about rims based on information in another question.  The person asking states that he doesn't want his rims wearing down.  Is this really a problem?  Assuming you don't wear the brake pads down to the metal, can the rubber pads actually wear down rims?  Does it make a difference if you use aluminium, steel, or carbon rims?  My rims are aluminium with  tiny grooves on them.  Is there anything I should look for to ensure that they aren't worn down?  I have over 10,000 KM of mostly city riding on my bike.

Short Answer: Yes

Longer Answer: Yes, but maybe not for the reasons you are thinking of. Rim wear is mainly caused by dirt and grime that gets caught between the brakes and the rim, rubbing it like sand paper. The most important thing to do is clean your rims and pads as often as possible. For that matter clean your drive train as well.

As far as different materials go, it is a lot easier to bend back steel than aluminium or carbon. So if you do have a steel rim you are better off if something goes wrong. There is a tool called a dental caliper (pictured below) that can help you find out if your rim is worn down.

Here is an interesting story and some good info on bent rims.


If a slime tube hardens when exposed to air, why doesn't it harden when I pump it? A question for the philosoraptors :v

For the same reason a salt-water solution in a closed half-filled bottle will not evaporate - even though it is in contact with some air.

Open the lid - and eventually the water evaporates to leave just salt.

The slime solution is in a "balance" with the air in the tube - since it is a "closed" system. When the tube is punctured the slime flowing out of the puncture is no longer in a "closed" system and evaporates / dries in the open air.

Takes me back to Chemistry and reaction kinetics (yuck) .. but anyway that's my take on it.


Curious about foot position on clipless and regular pedals when mountain biking I normally ride flat pedals and being a mountain biker with a little bit of training behind me, I pedal with the balls of my feet in front of the spindle. I had a pretty good trainer and once I started using this position I felt not only more planted on the bike but my calf muscles didn't need to work even half as hard for a normal pedal stroke.

My question really is, why use the position that SPDs and clips enforce? Is there a greater power transfer for sprinting or something? Having to counteract the pedal stroke force with the calf muscle surely is tiring out more of the body than is needed and there's surely more chance of over exerting the muscle.

I'm just asking out of curiosity as I'm unlikely to alter the pedal position I ride in.

Clip-less (and before them, clips) came out of the road riding community where the emphasis is on power transfer and efficiency.  The most efficient position is the ball of the foot on the spindle (+/-1 a few mm). if you look at all early, and most modern, road shoes and cleats, its clear they are not suited to mountain biking and are designed for one task - the no compromise transfer of as much power from the rider to the bike as possible.

When MTB'ers started to use clipless, the advice remained "ball of foot" position, however by the late 1990's it was shown for MTB riders this is flawed  - that the stability and control offered with the foot further forward (In the extreme, spindle under the arch) provides a far better outcome when riding. How far forward/back is always a trade off between efficiency and control/balance. With flats, its not an issue - move your foot forward fro the gnarly downhill, back for an uphill grunt.

It took a long time for the  ideas of those pioneers to been widely acknowledged. Its only in the last few years (its taken this long) MTB shoes are being manufactured with the slots for cleats further back than previous models - I knew elite riders in the late 1990's who drilled holes and mounted their cleats behind the slots of shoes available at the time.

You will still hear a lot of people repeating the dogma that the ball should be over the spindle, they are very wrong, and the more extreme and technical the Mountain biking, the more wrong they are.

Another question that needs to be asked by every Mountain Biker who rides clip-less is 'Why, what advantage do they give over flats'? - the reason I mention this is if the roadies use clip less for one thing, improve power transfer, and the cleats back position we use on MTB is a compromise, whats the gain we are getting.