Grabbing the attention of the person ahead of you while bicycling Normally you let the bicyclist/walker/jogger ahead of you know that you are about to pass them by shouting "passing" or even by just ringing the bell on your bike. This is done as a courtesy since many people do get scared/shocked if someone just zooms by them without notice. It's also a safety issue since the person could accidentally or knowingly go to the left side of the path and you'd run into them.  For example, they could see a cute duckling on the left grass and start walking over towards it forgetting about looking behind them and bam, an accident!

  Ride to the right on multi-use paths and warn other cyclists, walkers, runners and path users before overtaking and passing them. Call out “passing” or ring your bike bell.
  From https://bicyclecolorado.org/learn/colorado-bicycle-laws/

However, now a days many people (usually younger people) will be blasting music in their ears through their headphones. So I've noticed that many times these people don't hear me shouting at them that I'm passing.

Here's three options I've came up with:

I could just keep going at the same fast speed and just blame them if they get hit since they are the ones that thought their music was more important than safety or listening to the sounds of nature.
I could slow down to a safer speed and slowly pass them reducing the chances of an accident.
I could carry some small pebbles with me and then just chuck 1 or 2 of them about 6-8 feet ahead of them to grab their attention.

I don't really prefer any of these three options, is there a better way to grab their attention when shouting doesn't work, while maintaining the same faster speed?

You already known the answer (2), but do not seem to care much for it.  The reality is that you are the fastest user on the shared path thus you bear the most responsibility.

I would suggest

When approaching, slow down to an appropriate speed.
Make an attempt to notify (bell or calling out), even if they have head phones on.
If they do not respond or move, then further adjust your speed and position on the path appropriately to ensure you can safety pass.

Because you are moving faster, you have the most momentum and will therefore inflict the most damage in the event of an accident.  If the other party is unaware of your presence then you bear most of the responsibility here. (A couple weeks ago I attended a multi-use path crash where one user had their face caved in due to the speed of the other user.  You would be surprised the damage that can be inflicted.)

The reason I would call out or ring a bell even if they may not hear you is liability in the event of an accident.

Finally, it pains me that many complain about the way that some motorist bully cyclists on shared road ways, then go on and do the same to pedestrians or other slower users on shared pathways.


Shimano PF-M545 pedals Mavic Alpine All Mountain Shoes how to fit the cleats I just bought Shimano PD-M545 pedals and Mavic Alpine All Mountain Shoes (links below)

Shimano M545 Free Ride Pedals
Mavic Alpine All Mountain Shoes

I did do some research and "think" I got the best thing for me for the money I had, and that they work together, Bike radar says they are SPD type shoes.  They seemed to look right.

They arrived today and I sat down to try and fit the cleats to the shoe.  My problem is the 4 screws that came with the pedals are larger than the screw holes in the sole of the shoes.  It almost looks like there is an inner screw hole in the shoe, (but I could be wrong).  It doesn't seem like it should be a complicated process.. Have I bought the wrong shoes, being completely stupid or missing something?

Thanks for any and all help, (this is my first time with any clipless shoe).

Turns out that there was a male screw thread inside the female and I needed an allen key to get it out. (I had to go to bike shop to learn that, though.)

After that point the rest was clear sailing, following the instructions closely, and watching some online video tutorials about it.


Bike Pedal Falling Off While riding her bike my daughter's pedal came off. It appears to be stripped. This has happened to her with a total of three bikes. What could be causing this to happen?

The only time I've seen pedals in a newish bike strip out of the crank was when the mechanic who assembled the bike overtightens the pedals (the mechanic was a younger me, but you live and you learn.) Often, people will forget that left pedals are left-hand threaded and will strip them out when they try to remove them.

The mechanical motion of pedaling causes metal-metal mating surfaces to fret - microscopic motion back and forth causing noticeable wear. If this were a bike from the 70's with aluminum cranks it wouldn't be a surprising failure mechanism. However, since these are new bikes, the most likely explanation is that who ever assembled these bikes tightened the pedals too much. There is no way a child could be riding the bicycle enough to cause a pedal to strip out. To have it happen three times is incredibly unlikely, though.

I'd avoid buying department store bikes and refer to your local bike shop for any repairs or replacements.


Bottom Bracket Press fit to a square taper I like to use my old Campagnolo crank on a new road bike frame. The frame has already a Pressfit BB71-41A installed. The crank needs a sqaure tape. Is it possible to use the crank with a adapter or do I need to buy a new frame/crank.

Bike Frame: used Bulls Desert Falcon Pro
Crank: Campagnolo Racing T 9 Speed

I'd say no. If the frame had a screw-in BB shell you could simply fit a tapered axle and bearings. Looks like you'll need a new chainset (that comes complete with axle) - however you could get rid of the cheapo BB71-41A (MTB type - why would anybody fit this?) and fit whatever bearings suit the chainset of your choice


How should I fix my Ortlieb Rack Pack (medium, 31 litres) to my rear panniers? I recently bought an Ortlieb Rack Pack to go across the top of my rear pannier rack. When the pannier bags are attached the Rack Pack works great: it clips into the two pannier bags and everything holds together nicely.

However, if I'm only using one pannier bag or if I'm using the Rack Pack on its own, I struggle to get the Rack Pack secured to the rear pannier rack. I'm thinking of using a bungee cord, but should I try something else instead? Is there a different kind of strap that is specifically designed for fixing things to panniers?

I'd go with a couple of bungee cords, maybe the adjustable-length ones.  That's probably going to be more versatile and adaptable than something more specialized.

There are some flat adjustable bungees, like these:

http://www.amazon.com/ROK-Straps-Adjustable-Loop-Thru-BLACK/dp/B008ETMV8I

That particular type is attached on either side such that you can open it without having the entire strap coming off the bike. Both ends are a plain nylon strap, and the middle section is stretchy.  I've used these for motorcycle luggage and I liked them.


I want to ride a bike, but its dangerous for me to have weight on my arms I ride about 6 miles a day to work and back.  I would like to ride more, but because of a bum shoulder I am increasingly getting into dangerous situations and I want to give up riding.

I have a Giant bicycle that I got used off a guy.  It's a fine bike, but the angle is such that all my weight is pressing down toward my hands.  I have dislocated my shoulder at least five times from things that should not have even caused a problem (e.g. I ran over a walnut and my shoulder dislocated.  Another time a dog barked and the startle made my shoulder dislocate.  Both times I fell off the bike in the middle of the street).

Hopefully in the near future I can get some surgery to rectify the shoulder problems.  But I am looking for a bike that I can use for getting to work and back, with a more upright seating position that would put the weight on my butt, not on my arms.  I would also appreciate a bike whose gears do not ghost shift while going up a hill.  Any suggestions for what I should be looking for in a more suitable bike?

I don't have the rep here yet to upvote or +1 a comment re: @jqning 's answer so instead; I offer this "I second what he said about Townie."
I suggest Townie (w/ admitted/disclosed bias) because it is what I ride. I don't have a bad shoulder but I do have 1 artificial knee, 1 artificial ankle and nerve-damage in my right hand; all of which limit mobility. The model I chose is a 2011 18-spd 2200d electra. It suits my physical handicaps more-than adequately; being a "bike-person" few of my materiel possessions out-rank it. it would be almost impossible to replace; if I had to I'd go with their current model; which would not be optimal for me...but for someone with shoulder problems -- it would.

the problem with your current bike is the stance. you're pitched too far above and in-front-of the bike's center of gravity.

for your shoulder, you want to be hanging-back...behind it--like on a cruiser-style frame--- where the handles are elongated and reach back (even downward a bit) to get to your hands. **This needs to be done comfortably, safely and most of all, the bike still needs exceptional vel. & accel. (because it's a commuter) and primarily, **it needs to be fun to ride.****

check out their specs .... test drive an Electra -- the current models comes in 7speed (1 up front, the 1st gear in back is extra-extra low-low). try similarly-designed-bikes too. if I could list other brands/models I would...well Schwinn and the brand you have now likely produce a similar style - many of the larger brands have knock-offs; some =ly good; some (possibly) better; depends on your budget. This style can easily (prob. w/o a custom/after-mkt handlebar, seat, etc) be adjusted to lower your center of gravity so when ur ON the bike, it takes all (an extremely significant amount of...)the pressure off your shoulders and redirects/displaces it to parts your body that can bear it.

bottom line - in your question you said "...I want to give up riding." even though I take this a bit out-of-context...there it is; in the lead of your question - if you really did? you would not be on SE asking other OCD socio-paths what to do.

The bike is the problem - scrap it:

try a bunch of new bikes
new designs
new brands

Change "I want to give up" to "I should change bikes- don't give up."

Hope I don't sound like an advert-- the company no longer manufactures the 2200d - which to me, is a neg on their business strategy. in all fairness this statement should bring some objectivity back into my inherently biased answer.

If you LIKE riding; please don't quit. it beats walking, it's healthier and safer on your bones & joints than jogging and is comparatively FREE as opposed to a combustion engine, electric or hybrid ANYTHING. ALSO; the energy spent makes YOU healthier, as opposed to the spent energy of other vehicles; which mainly damage pocketbooks, the economy and the air.

Stay up, Tapper


replacing wheels on a hybrid running on 700c Using 700c wheels limits the choice of tyres and when touring tyres might be hard to find. Is there a problem in using 26 in wheels instead.

Brakes, tyre clearance, and lowered ground clearance are the three points.

If you have rim brakes, give up now.  They simply will be wrong, and buying super-long reach brakes will be expensive and won't work very well for leverage reasons.  Disk brakes may work okay, provided the rotor lines up, and your fork spacing is acceptable.

Tire/Tyre clearance should be okay because your new rim would be smaller.  However 26" tyres are often 1.75 or 2" so there may be clearance issues.  You'd probably have to go for smaller and not knobby tyres.

The bike will be sitting lower to the ground now too.  This will increase the chance of pedal strike going around corners, and the break-over height will be less, so you could strike the big chainring on the ground easier.

Surprisingly the wheelbase length will not change.  So "handling" should be unchanged.

Finally, the aesthetics will look somewhat weird, but that's only a visual thing.


What are the benefits of removable presta valve cores? Once again, I spent some quality time debugging a slow leak and found out it was a loose valve core. I tightened it with pliers, but it raises the question, is there a situation where it is useful to be able to remove the valve core? Also, have replacement valve cores been available at some point, and do the cores have a standard thread or is it manufacturer-specific?

As others have mentioned one reason is to make it easier to installed slime/sealant into a tube or tire. Typically you'll take the valve off, and use an injector to put the slime into the tire.

For tubeless tire setups, removing the valve core allows a higher volume of air to quickly get into the tire when you are first blowing it onto the rim.

Some types of valve extenders used by people with deep profile rims thread into the valve core threads.

Another reason to have removable Presta valves is they tend to be somewhat fragile so being able to replace a busted valve vs. having to replace the whole tube could potentially save a little bit of money (or allot of money if we are talking about breaking the valve core on a $150 tubular tire.)

The valve cores should be consistent from maker to maker.


How to Remove Specialized OSBB Aluminum Inner Shell I have a 2014 Specialized Tarmac that uses press-in aluminum inner shell cups to hold the bottom bracket BB30 bearings.  These cups are affixed to the carbon frame with 2 part epoxy.  (see page 2 of this tech guide:  https://media.specialized.com/support/0000003319/0000003319_IG0338_revC.pdf).  I would like to replace the cups.  How can they be removed without damaging the carbon fiber frame?  (for a picture of the shells, go to page 3 of this link, and view the 2014 alum. inner shell to the 2014 SBC Road Frame:  https://praxiscycles.com/wp-content/uploads/PRAXIS-FRAME-GUIDE.pdf)

I have a carbon framed bike with a press fit BB. Recently the non-drive side bearing disintegrated, and having the Park tool to remove/install the cups I thought I'd be good to go.

The drive side cups popped out no problem, but the non-drive one had frozen solid in the way that aluminium seatposts can in carbon frames. Despite hammering it like all bezoomny, to the point where bits of metal were breaking off the inside of the shell where the tool rests against, it would not budge.

In the end I got a dremel and very very carefully cut through the remaining bearing shell and then the BB cup, and it still took some pretty good whacks with a hammer against a wooden drift for it to finally give up.

So, get the right tool, or take it to an LBS/mechanic who does. Its surprising how easy the cups can pop out when done properly. Failing that, and as a total last resort, you can cut them out with a steady hand.


How do I prevent neck and back pain, and recover physically/mentally on a multi-day ride? I'm nervous about the ride and looking for some motivation, support and answers to a couple of questions.  I'm a 53 year old female and I've done 75, 80 and 100 miles before but never a two day ride for a total of 180 miles.  I've put quite a few hours in on my bike but I'm getting nervous now.  I know I can do the first day but I'm concerned about the second day and how I will feel.  I tend to feel a lot of burning across my shoulders and neck after about 50 or 60 miles.  Question 1: What can I do to prevent this?  Also, what should I eat the night before the ride and is there anything I can do to prepare myself mentally and physically after the first day?  Can I do this?  I won't back out now............I told my family I was crossing the finish line even if someone has to drag me across.  Please help!  I'm not even sure I can sleep tonight!

Don't be afraid to get off the bike.  Take a break every hour or so. Shake out your legs, shake out your arms.  Stetch your muscles.  When on the bike, try to remember to switch hand positions often set a timer on your watch every 10 minutes if you have to to remind you to switch things up a bit.

Eat before you are hungry, at regular intervals.  Don't wait until you feel hungry to start eating. It's already too late at that point.

Don't drink too much on the night between the rides. I don't know about the ride you are going on, but a lot of these two day rides have "refreshments" available at the end of the first day. A cold beer can be nice to relax you, but don't overindulge.  You'll regret it the next day.


Does new chainring require change of other parts? I'm thinking about changing my 2nd chanring to a smaller one (2 chanring setup). I hear most people recommend to change the chain when changing the cassette.

Hence my question: should I expect to change other parts (chain? other chainring? cassette?) if I change my 2nd chainring?

Thanks

It would be wise to check the chain wear with a chain "stretch" gauge and replace it if the chain is beyond 0.75 or 0.8.  Re the rear sprockets, they're only likely to be a problem if the current chain is worn beyond 1.0 stretch.

The other thing to worry about is whether the derailers can simply handle the difference.  The rear derailer has a "tooth range" in terms of the greatest difference between the sum of tooth counts of the largest sprocket pair and the smallest, and if that range is exceeded then the chain will either go slack on the smallest combo or become over-stretched on the largest.

Further, the front derailer has a limit to how great a tooth difference it can handle, and too much difference could result in the chain rubbing the derailer or iffy shifting.

But these problems are only likely if the difference in old and new ring diameters is substantial.


Are today's bikes "better" than a few decades ago? I'm looking to buy a road bike for commuting. There is a guy near me who finds older road bikes (e.g. from the 80's) and fixes them up. Are there downsides to getting an older bike (assuming it's had a proper tune up) compared to getting a bike released in the last year?

The last major technological improvement in standard bicycles was indexed shifting.  The indexing part of this isn't that big a deal, but the feature also gives you the ability to shift under load (which is a big deal).  I'm thinking this change occurred in the late 80s, but my memory for chronology is poor.

Yes, since then we've gotten V-brakes, carbon frames, "compact" cranksets and a few other things, but they're not fundamental changes, just minor refinements (if that).

Re "non-standard" bikes, the biggest change has likely been the improvements in geared hubs.  These have gone from 3-speed, don't-dare-shift-under-load-or-you'll-wreck-it models to multi-speed or continuous models that encourage you to shift under load.

There has also been progress in recumbent technology, but I don't think there've been any game-changers (though I'm not up on this).

The main problem with a bike more than 15-20 years old is that replacement parts get harder to find.  In particular, if you buy an older bike you might want to buy a spare rear cluster right off, to have on hand.  And I wouldn't recommend buying a road bike with 27" tires, since replacement tires (of the narrow "racing" variety) will be hard to find.


Are there any 8-speed brifters with internal cabling? I have a situation where the bike has (OEM) 8-speed Shimano Claris shifters with the cables coming out the side which interferes with the handlebar bag.
(Photo below). SRAM doesn't list any 8-speed brifters at all, and Campy 8speed ergos are only available (second hand? genuine?) from Ebay.
I'm looking specifically for brifters with internal cable routing - bar-end shifters are a fallback option.

The new Claris, called R2000, has internally routed brake and shifter cables, an improvement on a previous version, that still sported the externally routed shifting cables.
It is still 8 speed group, so in line with the op's wishes.

https://bike.shimano.com/en-EU/product/component/claris-r2000.html

dealers manual, page 13, how to install shifter cable:
http://si.shimano.com/pdfs/dm/DM-RBSL001-03-ENG.pdf


Anti-rotation washers (non-turn) washers in non-parallel dropouts? I have a Shimano Alfine 11 Interally-geared hub and am fitting it to an "M5 559 shockproof" recumbent.  The wheel is built and true and runs nicely.

However I have a problem with the anti-rotation washers and my dropouts.  The upper and lower edge are not parallel - they diverge at about 24 degrees.   The dropout is not damaged or bent open.

Normally this isn't a problem, but an IGH needs an antirotation washer that looks like this.  The "5L" and "5R" version is what I have.

The problem comes in that the tang on the washer is way smaller than the angle of dropout.

I think the washer's tang should be pressed against the lower part of the dropout, because the hub will want to "roll" forward under tension from the chain.  That is, NOT as pictured.

Your thoughts?   I know I will have to get a set of 7 or 8 to make the cable entry angle work better, but am I risking the health of the frame's dropouts by putting an IGH in at all?

The torque that the axle sees relative to the frame can happen in both directions as gears change.

For example in the classic Sturmey Archer 3 speed, it's the second gear that is neutral and does not place a torque on the axle.  In third gear the axle will try to twist forwards, and in first gear it will try to twist backwards.

For this reason you really do need an anti-torque washer and you can't leave the gap in the second picture above or below.

I would try to use a normal anti-torque washer against the inside face of the dropout.  This washer will have the square hole to grip the axle.  Then I would try to make a second washer-wedge-combo out of a softer metal (e.g. Al) to go on the outside.  The wedge part of this piece would fill that gap between the red lines in the second picture, but it's strictly functioning as a wedge and can have a round center hole.


Are all vintage bikes difficult to work on? I have had a couple of vintage bikes (from the '80s and earlier) and all have been absolute nightmares to work on: They always seem to have weird dimensions which aren't available anymore or in the area (e.g. Imperial sizing for bolts and threads or weird sizing for shift cables) or parts which don't even exist anymore (e.g. rod brakes). Furthermore, not only is it a pain for me to work on them, but most repair shops I go into won't even touch them because they can't get the parts necessary to fix them.

At the moment I am fed up with dealing with the above-mentioned vintage-related problems and problems from newer albeit cheap bikes, which I've also had in the past; Based on my frustrations with older and cheap bikes, it seems all old bikes are a pain to work on-- is this true? On the other hand, is a "proper" modern bike such as one from Cannondale, Trek, Genesis, Surly, Salsa, Kona, Specialized, Fuji etc. with e.g. brifters and cantilever or disc brakes going to be more enjoyable to work on, or are they just as annoying as old bikes? In other words, does working on bikes just suck in general?

No.  Older bicycles are no harder to work on than modern bicycles provided you have specialized knowledge regarding older standards, possibly specialized tools and the ability to obtain parts designed for older standards.

Generally a bicycle built now will likely conform to a set of standards that are common and in place now.  If you bought a bike today, and purchased all the tools necessary to work on it today, you'd likely find that new bikes five years from now would have a lot of overlap, but some standards would be new/different and a few new tools may be required.  In addition, all the parts necessary to rebuilt said bike would be available.  Five years from now you would have a lower percentage chance of finding all the parts, but it would still be very high.  Additionally some of the newer mechanics may not be familiar with your "older" setup, but there would be many around that were very familiar with it.

Drag this out for 30+ years and you see where it is headed.  A "vintage" (a term badly stolen from the wine industry and used incorrectly) bike will have mostly standards that are no longer used, require some tools that may no longer be common, and may or may not commonly have parts available.  Additionally, 30 year veteran bike mechanics are a rarity, so someone with all the knowledge of said bike is going to be hard to find as well.  It simply isn't worth most mechanic's time to try and figure out a bike from sometime around when they were born or earlier (especially when they are paid by the job).

People often buy inexpensive (or overpriced) "vintage" bicycles thinking that it should be cheap to fix up an old bike.  The truth is that it requires specialized knowledge, parts and sometimes tools.  It should be similar to what you would expect buying a 1978 Ford LTD that is rotting out and not currently running.


How to approach zone practice if heart rate zones are completely inaccurate I recently started training with a heart rate belt. However, my heart rate zones seem completely different from the information I could gather online.
First, I'm in my mid-thirties but have a maximum heart rate of 197, which is much higher than it should be. However, it seems for many people this can be the case.
Second, more importantly, my heart rate zones differ a lot from standard percentages. Cyclingweekly stated that 82-89% should be for efforts lasting a few minutes but it is ok for me to hold the mid-80s for several hours. 89% and above only works for a few minutes. I don't seem to have any heart rate zone to target for a 20 minute effort.
Third, the indicator about speaking seems completely inaccurate. At 87%, speaking one sentence at a time (usually zone 2) is possible.
My question is how should I approach cycling practice based on zones if I fall out of the regular categories? I would also like to know possible reasons why the zones can be off, especially in case this relates to health issues or lack of training in some respect.

Max HR isn't a particularly useful metric.
Not only is it particularly difficult to measure/estimate, but it can't be used to accurately define training zones, as there are large variations between individuals with regards to % of MHR they can sustain for various durations. It can even change for an individual based on their current state of training.
Basing zones on Lactate Threshold Heart Rate (LTHR) is a much more useful metric for determining appropriate training zones. The most common way to determine LTHR is by performing a 30 minute solo time trial as if it were a race, and taking the average HR for the last 20 minutes of the effort. https://www.trainingpeaks.com/blog/joe-friel-s-quick-guide-to-setting-zones/


Are all side-pull road bicycle brakes compatible? I'm new to road bikes, but have been building mountain bikes for many years. I purchased a cheap road bike (at BSO price level) which I am upgrading for fun.

I'd like to upgrade the brakes to something quality, as the brakes it came with barely slow me down. It has some side pull, single pivot generic brakes on it, and I'm wondering if I can upgrade to side pull dual pivot name brand brakes (Shimano 105/Ultegra or similar) without any other changes.

Basically; are there things to check for that would make some side-pull cantilever road brakes non-compatible with any others?

One thing to look out for is the size of the drop from the bolt securing the brake to the frame, and the brake blocks, to ensure the new brakes will fit in such a way that the blocks line up with the rims.

Probably if you have a newish bike, then any new brakes you buy will be of the same dimension as new brakes. But it's worth making sure they'll fit - more here:

http://sheldonbrown.com/calipers.html#reach

I recently bought an old steel frame and had to get some long-reach calipers as my spares were all short-reach and the blocks would have clamped on the tyre, not the rims.


Can Lezyne Stainless-12 chain tool handle be used as tire lever? This really makes me curious, Lezyne Stainless-20 has a separate tool -- tire lever (however I don't see clearly on pictures how it looks like). The specification of Stainless-12 does not list tire level, but judging how the chain tool looks like it seems it could be used as tire level (unofficialy).

So maybe I rephrase my question to be more precise -- did anyone successfully (without breaking/bending the tool and cracking the rim, etc) use the handle of chain tool (of Stainless-12, lower brother) as tire lever?

Once again: I am asking about version -12, not -20!

Update: Just to avoid any misunderstanding -- Lezyne chain tool handle:

Image taken from http://www.chainreactioncycles.com/

Based on lezyne's site specs, that 12 tool is not meant to be used as a tire lever.

I would say, having had a lot of experience using make-shift tire-levers while on the job as a bike messenger, that it would damage your rim, and cause aggressive wear to the tire sidewall (leading to side-wall blowout).

Save yourself the $20-80 in tires, and the $100+ in a rim/wheel. Buy some Pedros from your nearest bike shop.
http://pedros.com/products/tools/wheel-and-tire/tire-levers/

http://www.lezyne.com/product-mtools-stainlesstools.php#.VSkorJFVhBd

12 style:
"TOOL BITS:
    Hex 2, 3, 4, 5, 6, 8mm      Star Shaped T25
    Phillips-Head       Chain Breaker: (9/10/11 speed)
    Spoke Wrenches: Mavic Mtv, 3.22, 3.45"

Note: They explicitly list the 20 as having a tire lever, which is clearly a different tool.


Frame size is smaller than recommended I'm 191 cm tall and I want to buy UPTEN ZERO, the problem is the biggest frame size is "L" and is adapted for (173cm - 185cm) only, my question is it ok to ride a small bike? dose it effects me or what are the consequences?
Thank you

Is there a local bike shop near to you where you can go and try one for size and perhaps get advice?

I think, generally speaking, it's easier to get a slightly small frame to fit rather than trying to adapt a too big frame...


Why would higher fork contribute significantly to breaking the frame? When I recently cracked my frame near the headtube, every bike shop that I went to, asked me explicitly "Did you put a longer travel fork?".

Putting aside that apparently fork travel and fork crown height are two entirely different measurements, and that the fork height is actually critical, how does a higher fork contribute to higher stress in the frame?

Also:

What is the effect of lower fork than the original?
Does bike A, being sold with higher fork than bike B, mean that A's frame is stronger? Or is it just different geometry?

how does a higher fork contribute to higher stress in the frame?

By creating a longer lever, and stretching the end of that lever to a greater angle, it transmits more force to the bottom of the head tube (the part of the frame where the steer tube passes through). This can cause damage to the head tube itself or where it joins both the down tube and top tube. How does this happen? That longer lever is essentially trying to pry the head tube off of that joint.

  What is the effect of lower fork than the original?

A fork with less travel (or similar travel but a shorter overall length) will steepen the head angle which will make your steering a bit quicker and more responsive. Now, this does reduce the force applied to the lower part of the head tube, but due to the change in angle, increases the force applied to the upper part.

  Does bike A, being sold with higher fork than bike B, mean that A's frame is stronger? Or is it just different geometry?

Simply: no. Frames are like any other product where the visual inspection does not guarantee that the assumption is true. For instance, most tapered head tubes with fork travel X are probably stronger than a straight head tube with the same fork travel. The purpose of the bike will also determine a relative frame strength. A dirt jump bike with a 100mm fork will handle way more stress than a XC frame with 100mm fork. The trade off is usually flex, weight, or another metric.


Is it possible to mix the rings in the crankset? I wonder about such setup as buying 48/36/26T crankset and then replacing the smallest (26T) chainring with 22T one.

What I am afraid of that I would get quite significant 14T in difference and when shifting from 22T into 36T I could damage the chain.

So, is such mix -- 48/36/22T -- pretty safe or replacing the chainrings is only for actual replacing the used one to new, but exactly the same size?

I'm going to answer with regard to putting smaller-than-stock small rings on a triple crank in order to get lower climbing gears. Doing it with the middle and large rings presents other challenges.

It's possible, and a lot of people ride setups like this. Here are some hitches you may encounter:

You may, and often will, exceed the rear derailer's 'Total Capacity' number. One of a rear derailer's jobs is to keep the chain tensioned over all the gear combinations. Total Capacity defines how wide of a gear range a given derailer is able to do this for. What this means in practice is that when the chain is long enough to cover the large/large combination safely, which it always should be, it will be slack in some number of the small/small combinations. Riding in these gears introduces a risk of derailment or jamming since the chain is more free to bounce around. A lot of cyclists decide they're fine with that risk and just stay out of those gears, which works well with the habits of most touring and utilitarian cyclists in particular since for them the small ring is mostly just for steep climbs. The exact same concern arises when you try to get your lower gears by putting on a bigger cassette, only in that case you also need to lengthen the chain.
Current (I'd say 'modern' but I hold out hope for the pendulum swinging back the other way someday) triple front derailers can have pretty specific chain contact points sculpted into them, and they correspond with the ring combinations they're designed to be run with. And middle chainrings have shift-assisting features (ramps and pins) that expect the chain to come off a specific inner ring. When people talk about how getting smooth front indexed shifting relies on all the components being designed to work as a system, these are some major pieces of that. You will tend to lose some shifting performance for these reasons if you put on a smaller inner ring. Usually it will be in the realm of still working, but just being more sluggish, clunky, and finicky to adjust and keep adjusted. It is definitely something of an experiment every time, which is a reason shops may be reluctant or unwilling to do it.
Friction front shifting handles this kind of setup much better because you have more freedom to finesse it. STI in particular is clumsy to intentionally overshift. It can be easy for performance to feel mediocre or compromised when you do this on a bike with STI.
I don't know all the reasons, but bikes set up this way are often more prone to chain drop on the downshifts. Using a simple plastic chain catcher of the dog-tooth variety is a good idea and usually solves the problem more or less completely.


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

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

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


Are freewheels really that prone and susceptible to bent axles? I'm 90kg (198pounds) and I have a 27.5 hard tail mtb 9 speed freewheel and it is quick release. I only use my mtb as a commuter on roads and never on trail. I run my tires at 35-40psi.
Ever since i bought the bike, the stock axle lasted about 1000-1500 kilometers before my rear wheel started rubbing against my frame. I got it checked out and replaced at my local bike shop cus it was indeed a bent axle. After they had replaced it and replaced my bearings, it only lasted 200km befofe it got bent again. I went back had them replace it with a new one again and same thing happened, only lasted 200km. I tried getting it replaced at another bike shop near me and this time it ony lasted 100km before it got bent.
Is this because of my weight?
Or because my tires are too hard? Or are freewheels just prone to bent axles especially when you have more gears?
I have read somewhere that the greater the speed (7-9speed) the more it is prone to having a bent axle if it is using a freewheel.
I do plan on upgrading to a cassette type hub. I just fear that i may still bend my rear axle even after upgrading my hubs. That's why I want to know if there are other factors causing my axle to bend and will it it still occur if I upgrade to a cassette type hub due to my weight or tire pressure (if those are factors causing or contributing to a bent axle)
Sorry for the long post. Thanks in advance of your answers.

It almost certainly won't happen with a cassette hub. It can happen on standard axle cassette hubs, but it takes a lot, and there's basically always a dropout alignment problem at work in addition to heavy loads over time when it does.
Eight and nine speed standard axle (M10 or 3/8") freewheel hubs are the definition of a cynical design. They work terribly and exist only because hubs are fairly reliably overlooked by buyers of entry-level bikes. They're an utterly crass means for product managers to jam more bullet point type features into a given price point. They are that bad. Light riders are spared some of the pain, but what you're dealing with is common for heavier riders who wind up with them.
Five and six speed standard axle freewheel hubs put much less leverage on the axle where it protrudes from the locknut, and have a pretty minor version of the problem, even for a somewhat heavy rider. Seven is kind of in the middle but is not that problematic for most.
You could put in a solid Wheels Mfg chromoly axle, which means switching to nuts instead of QR, and it will mitigate the issues a lot. It's unfortunate if you haven't had that presented to you as an option. I don't necessarily recommend it though, compared to just putting the money towards a new wheel and cassette.


Cramps/pain in feet and toes after turbo trainer rides and cyclocross races Recently I purchased a pair of mtb shoes one size larger than I needed (due to lack of availability and time), sizes I needed: uk 11 the size I purchased: uk 12.

After a turbo trainer rides or cyclocross race I have cramps/pain in feet and toes.

Should I replace the shoes or could it be something else?

It's almost certainly the shoes but exactly what is a really variable question. New shoe problems tend to fit into the following:

1, Does the shoe fit properly (length and width)? Seems the answer is no as you got a size too big which means your foot will move a bit. This can be mitigated with the correct insole and you can even get mouldable ones which you heat, put in your shoes then put your shoes on.
2, Is the insole right? Loads of shoes come with an "average" insole which doesn't really suit everyone. My road shoes came with 4 sets of inserts to tune the fit properly and it's noticeable when I go back to the cheaper ones. Consider transferring your old insoles if they fit or get some new ones
3, Is the cleat position right? Given the shoe size is wrong, this will be hard to get right just by eye. I tend to take a few hours riding with a pair of shoes to get it approximately right and then maybe another 20-30 hours to get it exactly right. After that I either use the system the shoes use to retain the cleat position when I put new ones on or the low-tech approach of a marker pen.

I'd do 3, then 2 then if that fails and your feet still hurt, get new shoes.


Do we really need another bike size? OK, this is a rhetorical question that deserves to be closed as "opinion based", but gotta ask.  Why do we need to have "27.5 inch" bikes?

If you dig through the specs (they don't come right out and say), this is a 650B rim, which Sheldon quotes as being for "French utility bikes, tandems, and loaded-touring bikes; some older Raleigh and Schwinn mountain bikes", and which is otherwise known as 26 x 1-1/2".

Again - Following up with an opinion from a self confessed conspiracy theorist. Its about the money - follow the profit tree to its roots

When there were only 26" wheels a small LBS needed to have one wheel set in stock, and one sized tire ( maybe 5-10 variations). They would special order specific gear the the customer wanted and could easily stock enough to supply of the shelf something suitable for most customers most of the time.  The LBS had a range of MTB in stock - a few (maybe 10 bikes) would cover the requirements for 95% of his customers, and he would target a particular but broad market (Typically either Family and weekend riders, or 'cashed up cost doesn't matter wannabes and elite cyclists).

Now, the small LBS needs to stock 3 wheel sizes, in disc and rim brake style (6 wheel sets). They also need about 50 different tires on the shelve. The number of bikes required to be stocked by the LBS has also increased. He needs at least twice as many on the floor to remain competitive, but that much stock will drive him out of business. This is beyond the capability of a small LBS to do and still remain profitable. Mum and Dad now need to stock 3 different spare tire and tube sizes at home (Dads 29'er, mums 26'er and sons 27.5er').

Then there is the hype - 26'er is old, 29'er is so much better.  Followed by "well, you need a 29'er for XC but AM and downhill a 26'er is better - to be a serious cyclist you have to have one of each (with spares of course). Now, we have 27.5 - So, that 29er I sold you last year really is to big, and you know that 26 so last decade, well, have I got the bike for you.... It's only $$$, but I'll throw in a discount cause you are such a valued customer.......

In effect it is being pushed by the larger retailers, who can afford the stock level, to push the small LBS out of business. The  elite custom-builders where pricing is less of a concern will do very nicely out of it as well (No competing LBS focused on "reasonable pricing" will drive some people to them).

The net effect of all this choice is that the cost to us will skyrocket as the competition is shut down. We won't have competing LBS that offer personal service (except those that provide for the high end market) and will have to deal with the large, impersonal chain stores. The idea of talking to the mechanic will be seen as quaint, as the salesmen run the front counter. "Why talk the the mechanic, buy a new bike.... "

I believe the changes are mostly (99.99%) profit motivated to get more bikes moving from shop shelves to unused garage ornaments.


Rigid fork on GT Avalanche 3.0 I'm looking into buying inexpensive rigid fork (~50 EUR) for my old GT Avalanche 3.0 (disc brakes) to make it slightly better commuter bike. My daily ride is 10km one way on asphalt surface. What should I consider when choosing a fork? What parts would I need in addition to the fork itself to do the replacement? Won't I make it much worse? I'm okey with what I have now, but would be nice to go little faster.

To convert to a rigid fork consider

1) Fork length - to maintain head angle geometry
This depends on the travel of your existing suspension fork and the wheel size.
ie For older 26inch wheels - an 80mm Suspension fork was a 420mm rigid fork and 100mm suspension fork 440mm etc.,

2) Brake mounts - whether your disc brakes are post-mount, IS Mount or flat mount.
Adaptors can be bought to convert between them.

3) Disc rotor size - some rigid forks will have a maximum rotor size clearance.

4) Tyre clearance - though you are using it for commuting - bear in mind if you use an MTB tyre in the fork - determine the maximum tyre clearance.

5) Fork steerer length - if you are buying secondhand (especially). New forks will have an ample length of steerer to cut down. But secondhand forks, you must check and measure to make sure there is enough for your frame.

6) Fork steerer width / profile - unlikely to be anything other than a straight 1.125inch on your bike - but with tapered head-tubes you may have to change the lower crown race.


Why are there a large number of businesses that do not allow bicycles in the drive through? What are some reasons that business owners choose to prevent cyclists from using the drive-thru?  Are there legal issues?

Probably one of two camps:
1) They just don't think it's proper to ride a bike through a drive through, it's for cars they say.
2) They don't know if it's going to expose them liability if a cyclist is hurt or killed by a car pulling in to or out of the drive through.


What's typically wrong with cheap mountain bikes? I'm interested in buying a mountain bike. Recently, I was at a Decathlon and checked out their mountain bikes. They only had 3 fullies and I really liked the 700 Eur one. I didn't buy it outright because the dampening locking mechanism seemed to be broken as I was still able to push the handle down even after locking. Maybe you can tell me whether that's normal for any dampening locking mechanism / normal for cheap ones / definitely broken. Here's a short video of me pushing the handle with various amounts of force but generally the same amount of force before and after locking:

I'm not sure whether the one I found on their website that one because it looks different (maybe because it's a different color) but this one is the only 700 Eur fully they list.

I didn't only check out bikes at Decathlon but I also looked around bike shops when I was touring around or just cycling in town and came by one. I don't think I ever saw a fully that cheap, and anything that I'd figure comparable would've cost at least triple that.

Now I know very little about bikes. I never bought a new bike and never ever bought a mountain bike. I used the very old mountain bike my father bought some 20 or more years ago and didn't need anymore. But it broke down recently and is in disrepair, so I'm looking for a new one. It did not have fancy things like a dampening locking mechanism, so I have no experience with that.

What potential improvement is there when spending double the money? I don't wanna spend triple to money but double would be okay. I've got a feeling that I'm really missing something here but even after weeks of thinking about it, I still can't put my finger on it.

A fully for 700€ will be horrible. Bad suspension, heavy, few gears, bad wheels, bad tires …

At least get a hardtail where 700€ will buy you a halfway decent front suspension (where the lock-out actually works) and okay-ish weight. With wide, tubeless tires and good riding skills you’ll barely notice the absence of a (bad) rear suspension.


What's the difference between mechanical and hydraulic brake rotors? I just bought some replacement brake rotors for my Shimano hydraulic system, the box says they are for mechanical brakes, anybody know if this should effect it??

There is no distinction between mechanical and hydraulic in terms of rotor compatibility per se. The manufacturer may be trying to get at something else in a clumsy and arbitrary way. They could be saying it's a direct replacement for the rotor that comes in some other brake set they produce, or they could be falsely equating mechanical brakes with using only organic pads, or it could be a dainty ultralight rotor and this is their way of cautioning against subjecting it to the generally higher (debatable) temperatures that might be encountered in a hydraulic system being used in a more demanding brake application.
The compatibility distinction you want to make sure you're not on the wrong side of is using metallic/semi-metallic pads on a rotor for organic aka resin only. But it's not clear that's what you have if that's the only verbiage they give you to work with.


Metallic vibration sound while cornering - hybrid/CX tires I ride a Surly Cross Check with stock everything. When I take a corner quickly on asphalt, I hear what sounds like metal vibrating, seemingly coming from the area of my front wheel. I'm used to hearing buzzing from knobby mountain bike tires in the same situations, but this sounds higher-pitched and "harder."

Have you had the same experience? Do you think the sound is from tire nubs, or something else?

Check your headset first. Try to turn the spacers under your stem, if you can turn them by hand, your headset is too loose. Loosen stem, tighten headset, re-tighten stem.

Another possibility is a loose spoke, but this you'd likely hear even when not cornering. You can quickly hand check the tension of the spokes by "twanging" them like a guitar string. You will notice if one is off. The stock wheels (at least the pic I'm looking at) has a cross pattern on the front wheel so you can also squeeze opposing spokes. You will feel if one (or more) is off. If it is, tension the spoke(s) and re-true the wheel.

Happy Riding.


How do I disassemble these AHF pedals? I am trying to disassemble a set of pedals to service them but I can't figure out what tool to use on the nut (see photo). I just need them temporarily until I can cycle to the bike co-op to change them, so if I can't get them apart, can I lubricate them somehow when they are still assembled so that they turn more easily? I have an aerosol grease I could just spray in.
Many thanks! Gill

Open end of a combination wrench should work on the square nut. An adjustable wrench should also work but you'd have to be careful to not round off the nut.
You cannot properly grease the bearings with the pedal assembled. You will not be able to spray grease or lubrication into the bearings.


What exact size tires ORIGINALLY came on an older Giant mens Cypress bicycle? I have an 12-15 year old mens Giant Cypress bicycle. I am trying to find out what exact tire size originally came with the bike. I have been riding on smaller replacement tires that now need to be replaced. The smaller size that I have been riding on is 700 x 35C - 28 x 1 5/8 x 1 3/8. These tires are smaller (thinner) than the original. I would like to know the original size and if there are any options besides these current tires which I never cared for anyway. Thanks, Frank

The 2005 Giant Cypress came with 700x38c tyres.
https://www.bicyclebluebook.com/value-guide/product/92884/

Large volume tyres are growing in popularity over the last couple of years, so you should be able to find many good options in this size.


Suggestions for a new bike for a newbie Good Evening All,

Whilst I used to ride a bike on a regular basis around 15 years ago, I have no real knowledge of bikes.

I recently completed a Wiggle Ride, that my friends signed me up for, in Calais (50 miles) - half on a Giant hybrid heavy bike and half on a loaned carbon road bike (I still have pain thinking about that ride!)

That ride in Calais has prompted me to:
1. Buy a new lightweight bike.
2. Commute to work on a bike.
3. Get back out in the weekends and go on some on and some off road adventures.

Based on the three points above, I have been told a cyclocross or a road bike adventure would be the best fit.

I hope to purchase the bike via my cycle to work scheme and therefore have up to 1k to use from this scheme but I am happy to pay upfront an additional £500, taking the full cost to £1500.

A few friends, that are far more knowledgeable than I am, said the following brands are the main ones I should be looking for:

Giant
Specialized
Canondale

What would you all recommend in terms of make, model, group and type of bike?

Thanks in advance for your time and help :)

Congratulations on the 50 miles and deciding to get back into the sport.

An 'adventure' bike is probably a good choice for getting back on a bike if you want a road style bike (i.e. one with drop handlebars) that can take on some rough road surfaces and is comfortable to ride.

The characteristics you want to look for are:

More relaxed riding position (compared to road racing bikes)
Tire width 28 - 32mm
Disc brakes
'Compact' (50/34 tooth chainrings) or subcompact (48/32) drivetrain.

Adventure bikes have a lot in common with cyclocross bikes but are not quite the same. Cyclocross bikes tend to have more aggressive riding position and often a single chainring.

All the large manufactures have adventure bikes in their ranges. The budget you mention will get you solid alloy framed bike. You should definitely spend some time looking around at different bikes and do lots of test rides.


How does front projection affect stability? So I was reading this article called Stability of a Bicycle by David E. H. Jones and in it he talked about how front projection affects the stability of a bicycle with a negative front projection making the bike more stable because when the bike rolls it might lean to the side and then the front wheel will turn into the direction of the lean, which would lower the center of gravity and that would stabilize the bike. Is that correct? I didn't really understand his explanation of how front projection affects stability. Can someone help me out?

Jones refers to the horizontal distance between the front wheel axle and the steering axis as front projection. Front projection is the product of the fork offset (the displacement between the axle and steering axis, measured at angle perpendicular to the steering axis, not the ground) and the sine of the head angle (the angle between the ground and the steering axis). Fork offset is a measurement of the fork itself, front projection refers to the assembly of fork + frame.
The theory on negative front projection, as I understand it, is similar to the theory on trail.
Trail is the distance parallel to the ground between the steering axis and the center of the tire’s contact patch. With the fork pointed straight ahead, the contact area on most bikes will be behind the steering axis. This is because most bikes have a head angle between 0 and 90 degrees, and on most bikes, tan(head angle)*fork offset is less than the radius of the wheel. That is to say that for the same head angle, a larger front wheel and/or a smaller fork offset, will result in more trail. This pattern continues with negative fork offsets (I.e. the front axle being behind the steering axle, or mounting the fork backwards) as well.
Another measure that’s applied to steering geometries is mechanical trail. Mechanical trail is like ordinary trail except instead of measuring parallel to the ground, mechanical trail is the displacement perpendicular to the steering axis.
My understanding is that there are many theories on why a bicycle should be stable, but for me the easiest to visualize in terms of actively balancing, involves an inverted pendulum. If you’re tipping over to the left, you fix it by first pointing the handlebars towards the left, to bring the wheels under you. Likewise, if you were balancing a broomstick on your hand, and it was tipping to the left, you move your hand left to bring the fulcrum in line with its center of gravity.
The bike with negative front projection doesn’t get stable from turning into a lean simply because low center of gravity=stable; it gets stability because it has a greater tendency to turn in the direction of the lean, and turning in the direction of a lean is how you keep a bicycle upright. The backwards fork increases the tendency to turn towards a lean because the lever arm operating on the steering assembly (the mechanical trail) is greater.
Why does mechanical trail make a bike more stable? My understanding is that the friction force between the ground and the tire corrects the steering direction, and the more that force is offset from the steering axis, the more influence it has. When the bike is standing upright and rolling forward, mechanical trail tends to re-center the steering. Conversely, if you hold the bike upright and try to rotate the frame about the rear tire, because the front tire’s contact patch is behind the steering axis, it will rotate the steering assembly in the same direction. If you push the front of the frame to the left, you get a rightward force from the ground acting on the tire, and because it’s behind the steering axis, it creates a torque on the steering assembly turning the handlebars to the left. that translates into turning the front wheel into a lean when the bike is leaning, and helping it stay straight when the bike is upright.


Tire over inflated and went flat? I thought my tire pressure was low.  I pumped air to the maximum resistance and after four hour there was hissing of air continuously while I was asleep and it woke me, how can I fix it?

It's a new one, bought three weeks ago and it's only the front tire went flat.

A puncture. Maybe a bit of glass still stuck in the tire. The tire had already lost air then when you pumped it up it got worse.

Assuming it's a tire with a tube, you can get a tire patch kit or buy a new tube. If you're going to patch it, take the tube out, inflate it and locate the leak. Stick it in a bowl of water and look for the bubbles if it's hard to find. Mark it with a pen. Then let the air out, scuff up the area of the hole with a little sandpaper and follow the directions that came with your patch kit.

Very carefully inspect the tire. Feel the inside all the way around. If there's any grit in there, that's bad. Inspect the outside carefully and look for a cut and maybe a bit of glass still stuck in there. If the damage is very minor you can keep using the tire, but if it's a bigger cut, it's better to replace it.

Inflate the tube just slightly when putting it back in the tire so it doesn't get twisted. If you have it, put baby powder on the tube before putting it back in it will help it get seated nicely.


Presta Valves keep failing New to this site. Hope you can Help. I have been commuting on a hybrid for years. A nice CUBE with hybrid tyres with Scrader valve. The odd puncture here and there. Par for the course.

Now I have finally upgraded to a Willier Izoard, with race tyres and Presta vlaves.

First couple of trial rides no problem. Then this weekend I went to go out and realised that the tyres were fairly flat. I hadnt ridden this bike for around a month so I figures the pressure had just dropped.

So I topped up with air. Back wheel was fine took to 110PSI (Max 120). Did the same on the front wheel and went out riding. Within 10 mins, I noticed front tyre was completely flat. It seems the valve failed as I could pump the tyre back up but then as soon as it relased the air just shot out of the valve!

I had a spare tube with me but no pump or tyre spanners. Luckily, I bumped into a very nice Bulgarian chap who was preparing all his kit for a two month cycling holiday and had all his gear literally out in the street. This guy really knew his stuff and within minutes he had changed the inner for me (and way quicker than I could have done it by the way" Had the tyre pumped up (to 100 PSI this time as thats all his guage went to) and off I went.

Within another 10 mins the tyre was completely flat again. Once more it appeared as if the issue was wth teh Presta valve, and this time it would take no air in either.

I find it hard to believe that I would get two complete valve failures in the space of ten minutes on two seperate tubes, especially when it was replaced by an expert!!

Does anyone have any ideas what maybe goign wrong here? I am a bit of a Noobie to race tyres so would appreciate any suggestions? It is a brand new bike so I doubt it could be the rims, and I checked tyres for holes pinches tc, but it does seem to be the valve. Werid!

Presta valves are fairly fragile things. It's easy to bend the stem once it's unscrewed. They work by the tube pressure being higher than the atmospheric pressure. This causes the valve to be forced closed. It is not until you either loosen (unscrew) the valve and depress the stem or place a pump on it and increase the pressure above the valve until it is overwhelmed and allows air in.

Point is, you can leave the valve "untightened" and air won't escape. The valve mechanism failed because for some reason it did not return to a closed position completely and leaked out. Then when you tried to top off the tire again it was further stuck Two best guesses:

1) You had a run of bad tubes. Welcome to road cycling. Things are more fragile. This is my first choice. Buy a different brand and see what happens.

2) Schrader valves are more durable and forgiving of rougher treatment. Perhaps you were use to them and when you topped off the presta tubes you bent the valve core and it wouldn't fully return to sealed.

Don't give up. I've had bad tubes before.

And one last thing: If you are a valve bender (like myself) I found the cure. Silca and SKS both make a chuck that doesn't need to make contact with the valve core. It uses the pressure from the pump to overcome the resistance of the valve core. Here is the SKS version, currently on sale at Saint John Cycles. You just push it on and pump. Couldn't be easier or more effective. Good only for presta though.


Difference between Shimano GRX400 and SRAM Apex I'm currently interested in a gravel bike and am in the process of mapping out my options. One parameter that is very obvious is that some models come with Shimano's GRX400 groupset and some with SRAM's Apex.

Interestingly, while not gravel-specific and if the internet is to be believed, being roughly equivalent to Tiagra, Apex seems slightly more expensive.

What am I missing in my comparison?

SRAM Apex comes in 1x11, Shimano GRX 400 is 1x10 or 2x10.

SRAM uses the small shift lever for both up and downshifts. On Shimano system the whole brake lever moves inward and is used for downshifts on the rear and up shifts on the front Personally I prefer the Shimano system as it makes it easier to downshift while braking and give more authority to up shifting at the front.

SRAM shift levers have a far more positive click to them. SRAM uses DOT fluid in hydraulic brakes whereas Shimano uses mineral oil which I think is a bit cheaper.

The best thing to do is test ride some bikes and see how you feel with the operation of the shifters. Also pay attention to whether you want a 1x or 2x system. 2x systems give you smaller jumps between gear ratios and a wider overall range.


Does changing gear relation produce different speed at same applied power? When you are starting the ride, I potentially believe ("know?") that with a smaller plate(cog with fewer teeth in the rear cassette), you obtain more velocity than with a bigger plate(cog with more teeth, in the rear cassette), applying same human power consumption on both cases. In first case (the correct way of starting the ride), the chosen plate radius is small, so it weights less and offers less resistance.

Once bike is running at a normal speed on flat terrain and gear's start resistance has been overcome, I want to know if I will get more speed with a smaller tooth rear cog than with a bigger cog, applying same human power consumption on both cases.  Changing relations would of course mean I should ride faster of slower in order to waste my same power in all cases, basically because the different resistances of the plate, which depends on its chosen radius mostly.

So let's say I want to be using 200 Watts. Would different gear relation setups affect the output speed?

If my statements above are wrong in first please, correct me.

Yay! Another physics question.

Restating the question: if the rider power input is constant, does the bicycle velocity change if the drive-train gear ratio is changed?

Let's assume the road surface, wind speed, gravity etc. all remain constant. Bike and rider are on a surface with no gradient.

Short answer is that constant power results in constant velocity regardless of gear ratio. Gear ratios change angular velocity and torque but because the product of the two is constant power remains the same.

Power at the rear wheel = power provided by rider - power loss in drive-train.

If the power loss in the drive-train does not change with gear ratio selected, the power at the rear wheel does not change and hence velocity does not change.

Of course, the power loss in the drive-train will depend on the gear ratio selected to some degree. I believe the chain travelling more slowly around a larger sprocket consumes less power (I'm not sure on this so somebody please correct me if I'm wrong).

However the power needed to overcome air resistance and wheel rolling  resistance is much greater than drive-train losses (if the velocity is not very low), so a change in drive-train losses will not effect velocity very much.

Update: addressing this statement from the OP (edited), as I think it's crux of the misunderstanding.

...with a smaller [rear sprocket] you obtain [higher] velocity than with a bigger [rear sprocket], applying same human power...

That would be true if human power was replaced with pedaling rotational speed.


Using head light as bar light? Lately I have been using a head lamp, installed on my helmet, while commuting to work.

For improving safety, and considering that I have a bar fixture for a handlebar bag which is unused for my commute, I was thinking of having a 3D printed thingy to attach the head lamp to the steering bar via the fixture.

Is there any shortcoming on this?

It depends on the beam shape. My commuting head torch has a narrow beam. While I mainly use it in addition to a handlebar light I have ridden with just the head torch, and found that I'm constantly scanning the beam. You can't do that on the bars. Other head torches aren't much use for illuminating the road in front, as the light pattern is too wide, but some would be perfect (often the more expensive ones).

Unless your access to a 3d printer is free, a cheap light might be more cost effective and then you'd still have the head torch. The mount would have to be quite robust and well fitted to avoid vibrations misaligning the light.


Sidewall repeatedly splitting in same place on rim Good afternoon, folks. Wondering if anyone has had this or a similar issue:
I blew a tire a few weeks back and replaced the tube and tire after thoroughly inspecting the rim for damage. After a few rides the air in my tire let go while sitting in my living room. The sidewall had spread open and I assumed it was faulty rubber. I've since replaced the tire twice and each time, after a few rides, the sidewall splits at the same place on the rim. I've inspected the rim and there seems to be no visible damage but it's starting to get expensive to troubleshoot. Below is a picture of similar damage to illustrate (not my tire but same result)
Thanks for any input!

Mark and note where the split happens on the rim. It's possible that the fault on the rim is only discoverable when the tyre is inflated. Perhaps, there is a crack in the rim. If you have a pair of callipers, measure the width of the rim with the tyre inflated and uninflated. This may highlight such a crack/failure.

Also check the geometry of the wheel by slowly turning it and examining the rim at the brake block as it rotates.

If either of these tests show problems, the rim should be replaced


Adjusting derailleur with bike upside down, is it ok? I need to adjust the derailleur on my bike, I don't have a bike stand.  I have three options for pedaling while adjusting the the derailleur.

Turn the bike upside down, balancing on the handlebars and seat.
Tip it up on the kick stand
Lay it completely on its side (if no kickstand)

Upside down is easiest, but it seems like that might not be the best choice.  Is it ok to adjust the derailleur when the bike is upside down?  Is one method clearly better then the others?

Turning it upside down seems to make the most sense, assuming it can be easily balanced. Derailleurs work by spring and cable tension, not gravity, so there should be no problem with working on it with the bike upside down. The only issue you're likely to have is reaching the shifters (assuming they're bar-mounted). Also, if your bike has disc brakes, you should check out this post about potential risks of inverting the hydraulics.

I pretty routinely will invert my bike when working on it, as I also don't have a workstand, and it's never caused problems before.


Brake Lever Not Fully Retracting I've noticed a problem with the brake lever corresponding to the rear brake for a cheapo kids bike i'm working on. After squeezing the brake lever it won't full return to its resting place. This was actually causing the brake to rub slightly until you pushed the lever back with some force.

After unhooking the brake cable I can confirm the issue is with the brake lever itself. I hit the inside of it with some WD40 and messed around with a screw that the lever pivots off of (without really knowing what I was doing). This helped a little but its still grabbing the back wheel.

Has anyone experienced this before/know what to do?

There are three "parts" or zones to a cable-operated brake.

1) The hand lever
 2) Inner cable and outer housing
 3) The caliper.

So you released the inner cable from the caliper.  Try pulling the cable through the outer housing and see how much hand pressure you need to apply... it should be relatively minimal.  If you have to get a good grip and pull with shoulder muscles, then the cable is suffering friction with the outer.

The fix here is to replace both the inner cable and outer housing.

With the cable disconnected, the lever should have tension and pull itself back to the open position without problems.  If it doesn't restore by itself, then it may be corroded, or deformed (ie plastic or metal bent)

You do say cheapo kids bike which normally means terrible plastic levers and budget stamped metal single-side pull calipers.  Sometimes these just get tired and the spring power is not enough to overcome the resistance from the inner cable.

Sadly some cheapo bikes are really not worth fixing - you have to make a judgement call.


Road Brifters with MTB Derailleurs I've just bought a lovely Surly touring frame and I simply stuck all of my mountain bike components on it.

That means I've retained a flat handlebar. I'd really like to stick drop bars on though and change to road "brifters" without changing the drive train.

I've tried Googling this and it seems to be complex issue so any advice would be most welcome. I have Shimano Alivio gears, front and rear plus a Shimano Diore crank (with the external bottom bracket type). The rear is a 9-speed cassette (11-30) while the Diore triple crank is a 48-36-26.

I really want to stick with this, not just because of the expense of buying a whole new drive train but also this set up gives me a really low bottom gear (30 on rear 26 on front) for getting up hills with a fully laden touring bike.

I understand I may need a new front derailleur but I may be able to get away with keeping the rear derailleur and using a ten-speed brifter such as a Tiagra with the 9-speed cassette. Is this right? Any suggestions would be greatly appreciated.

I don't see any problem with doing this on your bike if you use Shimano drifters. Generically there are two areas you'll need to consider:

The actuation ratio of the shifters, and
The brake pull.

Shimano 9-speed road and mountain derailers use the same actuation ratio. You should be OK here.

You don't mention which Surly touring frame you have so I can't be specific, but if its a Long Haul Trucker or Disc Trucker, your odds are good that the brakes will be compatible as well. With cantilevers you'll be OK as road and mountain versions use the same pull. V brakes will be a problem, they are not common on road bikes and the pull is different. I don't think know of a set of brifters for V-brakes. Similarly with discs, make sure that you are have, or are willing to switch, to road discs.


Front derailleur rubbing against chainring I'm trying to fix up my old (1999) Trek 4500, and I've run into a snag while adjusting the front derailleur. It's a Shimano FD-CT92 (bottom bracket mounted E-type), and it's rubbing against the largest chainring when it's in the middle gear position. There doesn't seem to be any height adjustement on that type of shifter. I've checked all the documentation I could find, and the chainrings are within spec (42T, 34T, 24T). In any case, all the equipment is original to the bike, and I've never had this problem before.... Any ideas on how to fix this?

Here's some additional info:

This is what the derailleur looks like when it's in the middle chainring position

The FD-CT92 derailleur is bolted to the bottom bracket plate in a way that prevents any height adjustment. A flange that fits around the seat tube also keeps the angle fixed.

(the photo below is with the derailleur detached from the bracket plate)

The only other thing that I've noticed is that the cage can be wiggled around a bit. Is that normal? Do derailleurs wear out?

bottom bracket has come loose slightly allowing the plate to turn.


Bought a frame one size larger, how to fit for slightly smaller rider? I've recently bought a frame that is about one size larger. It's a 22" frame and my height is about 5'9".

I had a choice between the 22" frame and an 18" frame so I chose the frame that was a bit larger because I had a bad experience on a frame that was too small.

What are the potential downsides to a larger frame and could it be fixed with adjustments such as a lower seat post.

Think of bike fit as a triangle, looking at a rider on a bike from the side, with a point of the triangle at the hands, a point at the saddle sit position, and one at the bottom bracket. Now with the bottom bracket position being fixed, it isn't always possible to replicate the exact angles and lengths of the triangle from one bike to another, but between one size and the next, you usually can get close enough to be considered equivalent.

You will want to lower the saddle height, adjust the saddle forward/back slider more forward towards the hands, and you will want a shorter stem, perhaps with a modified angle to get your hands where you want them. You should also consider the length of the crank arms, as sometimes manufacturers will configure different crank arm lengths for different size bikes. Most bikes are sold with longer than ideal crank arms anyway, and should be one of the first components considered for replacement. The main concern with frame size (aside from stand-over height), is the angle of the line drawn between the bottom bracket and the saddle sit position, as that affects the angles and forward/back position of the knees throughout the pedal stroke, and also where the rider's center of gravity is centered between the front and rear wheels (which is a primary input to how the bike handles or feels). A secondary consideration is the stem length, as too short and it will negatively affect steering characteristics.

Most will prefer a smaller frame configured larger rather than the opposite, with the added weight due to more frame material of the larger bike often cited as a complaint. I'm riding an undersized frame presently, with a lay-back seat post, and I look forward to having a better fitting bike someday where I don't feel so much like I'm sitting right over the rear wheel. It feels a little too twitchy; having the center of mass more between the wheels makes it feel a little more like you are riding in the bike rather than on top of it.


From Delft to Rotterdam - Hard? If anyone has done this before, I would like to know whether a bicycle ride from Delft to Rotterdam is hard (approx 15km).

I don’t know what to expect since the Netherlands is flat, but still.

This obviously depends entirely on your fitness level and your experience on a bike.

I will say that of all typical 15km rides, the ride between Delft and Rotterdam would likely be in the bottom 5% of difficulty, along with most of the rest of the Netherlands. I haven't done that route specifically, but from my time cycling through the Netherlands I can say that your ride is virtually certain to have no hills, cooperative traffic, and well-signed cycle paths. Unless you are grossly out of shape or have a physical condition that makes cycling inherently difficult, this is likely to be one of the easiest 15km rides you could possibly do.


How to correctly align "be seen" lights My "be seen" bicycle light is bar mounted and has to be reattached every time I jump on the bicycle, due to theft risk.  How do I determine when it is correctly aligned?

In particular how are "be seen" lights correctly aligned so they don't blind on-coming traffic, but so that they're best visible from a distance for on-coming traffic?

This question is primarily about how to adjust beam position for courtesy and safety, rather than the mechanics of mounting any particular light.

related question: How to correctly align "to see" bicycle lights?

With "be seen" lights good ones have a very wide beam pattern so they can be seen from all angles, which makes precise orientation less relevant. If you look at Nathan's bike light database most of those lights are about 180° horizontal beam spread and 90° or more vertically. Again, the better ones have a more even beam spread so there's really no "hot axis" that gets more light.

So I mount them for convenience. I look for somewhere I can attach them where they won't get bumped and point more or less along the axis of the bike, and more or less horizontally. Clipping them into the back pocket of my jeans rather than my belt, for example :)

If you have a poorly made "be seen" light that has a real beam and poor spread, the only real solution is to buy a better one. If you're using an old "see by" LED light in flash mode for this, I suggest setting it up as a "see by" light (per answers to your other question), and using it that way.

If it's particularly bright, the polite thing to do is turn it off or use a lower brightness setting when you're on the bike path. On roads the oncoming traffic should be some way out of your path so blinding shouldn't be an issue. If it is (really narrow roads, for example), I point mine down when I see oncoming traffic. Or turn them off. I have dyno lights that are always on, so turning the blinkie off doesn't break the law or make me invisible.

With my "see sense" lights that are designed to mount to a vertical tube and are annoyingly bright, I mount the front one to my head tube right under the stem so that I am shaded by the stem. That also helps a little with the upward part of the beam, but the real solution is to turn them down at night. It seems a bit odd, but a "daylight visible" flashing light is scary bright at night. So I run them on the lowest power setting at night (maybe ~30 lumens rather than the ~200 lumen peak). I can still see it lighting up reflective signs at 100m, so it's visible enough.


Gears randomly switching So I have a Trek Fuel SLR 90 and whenever I ride on flat dirt roads, the back gears randomly keep switching on me. It gets really annoying to ride Please help

If its just up and down one gear then you probably need to calibrate the derailleur cage a little using the barrel adjusters. Depending on the make of shifter and derailleur there will be a barrel adjuster on one or both ends of the cable outer which will allow you to make micro-adjustments to the cage position.

The jockey wheel centre should be roughly aligned with the center of the cassette cog. What you might find is that the jockey wheel is slightly left or right of the cog at a given shift position (the one that is jumping) so use the barrel adjuster to eyeball the wheel to line up with the cog. It shouldn't take more than a few turns to do this.

Also if the barrel adjuster is fully extended or screwed in, you may have to release the cable at the derailleur end and move it in/out to give you some adjustment room before reattaching the cable.

On the other hand if you are getting more than one shift up or down something is seriously wrong and you may have to replace parts.


Joe Blow pump extra parts anyone know where or how I can get a rubber insert for either presta or schrader head on my joe blow max floor pump? Just bought it and schrader head did NOT have an insert so it won't grab the valve. Is this a Topeak product? Would Topeak send me one??
Mike
Cambridge, MA

A good bike shop that is a Topeak dealer will likely have parts for the pump. You can visit the Topeak: Where to Buy page to find dealers in your area. Or contact Customer Service - they may just send you the parts for a minimal shipping charge or free; other companies have done that for me in the past.


Trimming Shimano FD-R3000 front derailleur My front derailleur is a Shimano FD-R3000. I have been trying to adjust it following the ParkTool video at

Basically it seems to be working OK now: the chain is not falling off the front chain wheels, and is shifting quickly to and from both the big and small chain wheel.

My question is really about trimming. On the large chain wheel at the front and the smallest two or three cogs at the back, the chain rubs against the front derailleur. (I have nine cogs at the back.) I understand that I can press lightly on the left hand shifter to trim - this removes the noise.

Then I move to the small chain wheel at the front. There is no noise when in combination with any of the rear cogs, except perhaps when I'm on the largest cog at the back. What is unexpected is that when I click lightly on the shifter now, the front derailleur cage moves - further inboard.

Is there supposed to be trimming on the small cogwheel at all with this front derailleur? And if so, is the low trim position really supposed to be inboard relative to the low position?

I am rather new to road cycling, so hopefully my question is not completely stupid!

Based on my interpretation of the text of the Dealer's Manual for your Sora derailleur, there is only one trim position which is a when after shifting onto the big ring from the small ring, actuation of the small, lever B, will move the derailleur slightly inboard while still aligning the chain to continue on the big wheel. See page 9 of the manual.  Now this trim position is meant to be used when you're in the large ring and beginning to shift up the cassette, at some point, usually around the 2nd or 3rd largest sprocket, the increasing chain angle may cause the chain to rub the inside cage of the derailleur making noise.  The trim feature kicks the derailleur slightly inboard--enough to stop the noise without actuating a shift off the big ring.

What is suspicious in your case as described is that you experienced noise when in the big ring and moving out on your cassette.  This is odd, because if things are in proper alignment, this large ring--smaller sprocket combination should yield a more proper chainline---the chain runs straighter.  Therefore, I suspect you need to check the initial alignment of the front derailleur: the outer cage plate should be 1-3mm (and the closer, the better) above the teeth of the big ring and absolutely parallel to it.  You should be able to take a hex key or any straight edge and while touching the outside edge of the outer cage plate, the other side of the straight edge should contact the outside of the large chainwheel, laying flat against the two. This is your necessary starting point.


reliable bike shifting I've recently had 2 bikes (Trek and Giant) of the hybrid style. The frame style was comfortable but both were difficult to change gears. When going up an incline, I would shift to a lower gear. The chain would slip, pop, clatter, and sometimes fall off completely. I took them back to the dealer who adjusted the shift cable but that did not correct the problem. I got rid of both of them. Is there a bike that does not have this shifter problem? thanks

I had a similar problem, but through trial and error learnt that actually I was the problem, not the bike. If I change down to the desired gear before reaching the bottom of the ascent, there was no further problem.


What's the beefiest front shock (26"), avail in quick release, with travel of 100-125mm (no more)? Details:  I mostly enjoy XC and all mountain riding. However, I also from time to time, will go out with friends on some much more intense downhill trails.   I'm also about 240 pounds, give or take.    So, while I really really like my bike, and the geometry is fine (as far as I'm concerned) even for some downhill.   The fork I'm running now is an older Fox 125 RL. But, being 245# and bombing downhill really makes me nervous.  Since my bike is pretty high-end (titanium fame, King/Thomson/Race Face.....etc), I'd like to just (if possible....and maybe it isn't) add a really, really solid fork up front.  Weight it not an issue (for obvious reasons).  Geometry obviously is, as the bike is designed for 80-100 travel up front.  I go 125....but that's it.   Is there such a thing as a fork with 36mm or larger uppers with only 125mm or less travel??

Hope I can turn this xc bike into one that can handle anything thrown at it with my 245# riding.   ??

You could look into dirt jump forks, such as the Marzocchi Dirt Jump or the RockShox Argyle.  There aren't too many options left for burly forks with 9mm quick release drop-outs.

Honestly though, Fox makes some nice forks.  Email their support and describe your use case (avoiding terms like 'hucking' or '6 foot drop to flat' unless applicable).

I would be more worried about an XC frame and wheelset failing than a modern suspension fork from a reputable brand.


Cannot shift into lowest gear I've been fiddling with my rear derailleur trying to fine tune it, because I just replaced my entire drivetrain (same components, but new)

The problem that I'm facing now is that I can't seem to shift into my lowest gear.

Derailleur hanger doesn't seem bent.
The derailleur itself doesn't seem broken or bent.
I also know that it shifted into the largest gear before so whatever I did must be fixable.

Here's a picture when I'm shifted in the lowest gear:

Either the L screw which limits how far the derailleur can move towards the wheel is too far in or the cable tension is too low.

Try to increase the cable tension first by turning the barrel adjuster on the derailleur counter-clockwise. However, it looks like it’s already pretty far out. If it’s at the maximum you have to shift to the smallest cog (highest gear), screw the barrel adjuster all the way in, unclamp the cable, pull on the cable as far as possible (pliers help) and then clamp it again.

If the cable tension doesn't help you have to turn the L screw counter-clockwise to allow the derailleur to move farther. Don't turn it out too far or the chain will fall over the cog into the spokes.

Park Tool offers a good tutorial here: https://www.parktool.com/blog/repair-help/rear-derailleur-adjustment


Can I use a road bike stem on my mountain bike? I've got a XC mtb which 1. I'm trying to cut the weight off , 2. I want a bit extra reach. I've got a longer road bike stem made by 'Deda' (I think Planet X)? and I was wondering if it will be strong enough for XC mountain biking use?

For XC and trail use it'll be fine.

It's really only downhill bikes that require especially strong stems, I think (and in that case you'd likely be using a shorter stem anyway for handling reasons).


Shimano Claris vs 105? I'm planning to get my first road bike as I have been putting a lot of miles into my hybrid. Did a century last Sunday. Altogether I have done around 5k miles on my trek hybrid. So I thought getting a road bike isn't too bad an idea.

I went to a LBS and the mechanic told me it is better to get a Shimano 105 group set because it is a lot better than Claris. He mentioned how the transmission would be smoother. I'm NOT planning to buy a bunch of road bikes in future so in most cases this will be my only road bike even though I would keep my hybrid for my commute to work.
So do you think it is better to get 105 over claris?

Being a newbie in to road biking  would it make a big difference?
After doing a bit of research bikes with Shimano 105 is kinda expensive and getting a carbon bike with 105 is pretty much on the similar price range to getting the aluminum bike with 105.

So I'm wondering whether I should get a carbon bike with Shimano 105 or an aluminum bike with 105 or should I get just a cheaper one with Shimano Claris?

Please let me know if I should be looking into some other groupset.

I've never used Claris, but I've used a bunch of different Shimano road stuff, from 8 to 11 speed, as well as some SRAM.

All other things being equal (which they never are), the more expensive Shimano groupset shifts smoother than the less expensive one. That, however, is splitting some really fine hairs. The shifting performance for modern brifters is nice across the board. In my experience, what makes a groupset good is how well you adjust and maintain it.

I vote for the Claris group. 8 speed is still widely supported and will probably remain so--you are unlikely to have a problem finding replacement parts (which are also much cheaper than 9, 10, and 11 speed parts) before you trash the whole groupset. 16 gears is also a pretty good range for any kind of riding.


Lock to fit around Big Apple tyres (28x2.35) I have a new bike on the way which has Big Apple tyres (28x2.35), which will be my first experience with tyres this big. I'll also be installing fenders.

I'm wondering if my Kryptonite Evo Mini-5 is going to fit around the rim/tyre/fender (Sheldon Brown-style), and if not, is there a Kryptonite U-lock which will?

I'd guess the big apple will make it tight depending on what you lock to.

Certainly the long shackle variants or standard shackle variants will fit around this. I have a Kryptonite New York Lock in a long shackle variant can fit around pretty much anything.

When you get the bike, you can easily measure the width the lock needs to have along with the length of the shackle to lock around what you need to lock to. I carry one New York Lock Long Shackle and 1 Fahgettaboutit so that I can lock in tighter places (and lock both the front and rear wheels with U-locks). I'd think even if the mini isn't suitable for locking ot something, it would be good to lock a wheel to the frame (and use another U-lock to catch the other wheel and whatever you need to lock to).


Can I put a road bike tyre on a mountain bike? I am finding it difficult to ride a Mountain bike, I feel that it may be more comfortable to change the tyre to that of a road bike, which are thinner in size.

Please advise if I can do so.

They make slick tires for mountain bikes used as commuters (and fat slick tires which the air provides a lot of cushioning). Some examples are Schwalbe's fat franks or big apple's (these are more baloonbike) or Marathons . Thinner doesn't necessarily mean more comfortable - in fact, the smaller the tire, the less comfortable it will typically be (this is a function of the bike's geometry and setup as well as the terrain and tires and tire pressures though). Go to your LBS and ask them for tires for road use or commuting and they will probably point you towards something similar to the Schwalbe big apples. Currently on my mountain bike which i use for commuting, I use Geax Evolution tires since I got them very very very cheap (though something like their street runner or some of the Kenda Kwick tires are probably something better for just road use if you're cheap).

You can't just take a mountain bike wheel and put it on a road bike and vice versa - the brake mounts and what not have to match up (this has been discussed a few times on these forums, whcih you can find with search) which is difficult if they're running different sizes.


Type of permitted folding bikes on London trains & Tube? I have found quite a bit of information about taking folding bikes on trains and the Tube in London. Specifically it says you can take a folding bike pretty much anywhere.

However, having examined the small print of various train companies in the UK there is usually a distinction drawn between Bromptons and the rest, i.e. Bromptons, which obviously fold up really small, are considered "true" folding bikes while the other types of folders appear to inhabit some regulatory grey area, halfway between a folder and a non-folder.

I'm contemplating buying a Montague Crosstown. As you can see there, this has full-size wheels. Even if I wrap this in a bag I would anticipate getting some nasty looks if I take that on a busy-ish Tube / train in London, but I can cope with nasty looks.  Does anyone know what the actual regulations are?

Some UK rail companies, such as GWR (who operate some local trains in West London as well as mainline services) only consider bikes to be folding if the wheels are up to 20".

  Folding bikes with a maximum 20-inch wheel can be carried as luggage without any restriction. Please make sure you fold it before boarding.

That would exclude the bike you've pictured, unless you can pack it in a bag and call it luggage (checking the size of that too)


Why does my rear cassette feel like it's jumping when I put pressure on small cog? I just gave my bike a going over with new bearing cages in the BB and a new chain. After putting everything back on I indexed the gears - finally getting the hang of the front but first time indexing the rear derailleur. It all felt fine on the stand, but when I go uphill with the rear gears on the lowest cog (6), when the pressure is on the pedals I get a weird jumping, clunking thing keep happening.

Now I was told this could be because my rear cassette is worn, but I've had a close look and done the brake-on-pedals-pushed test, no play on the chain on any cog, looks fine to me, how does this look to you : The mech doesn't look bent, either. Is it just that I need to get my indexing in better form, and need to perfect the cable tension, or are there other causes for this (like maybe wear on the drive cogs - do they look like they need replacing below?)?

Those teeth are severely worn, just by visual inspection. Try a new cassette, chain rings, and chain. (Don't try changing just one.)

It could have been the grime that was holding the worn system together, and when you cleaned it all the play now shows up. In the future, if you replace your chain more often you can make the chain rings last longer.


Direct Pull (V-Brake) vs. Center Pull Cantilevers (pros and cons) I am looking around for an old mountain bike to ride this winter (and this summer when it is wet).

I was just browsing around and was curious what the difference was between

Direct pull brakes:

And Center-pull Cantilevers:

Sheldon Brown has a good description of both kinds of brakes but he does not give pros and cons.  Or suggest which are better.

The main reason that the direct pull (V brake) was invented is that it approximates a center-pull cantilever in terms of balanced force and leverage, while not requiring that the cable be anchored at some point above the wheel.  This is important for front wheels on suspension forks, but not significant for most other uses.

Another slight advantage of the V brake is that it doesn't generally protrude out of the profile of the bike quite as much and is thus somewhat less likely to be damaged in off-road use.

Neither advantage is of any importance for a road bike without a suspension fork.  However, there is the problem that the two require different levers (because the cable travel length is different) and the old cantilevered levers are getting hard to find, should you break one.


Do tire / tube / valve combinations that don't leak air exist? I'm not clear on why tire pressure decreases over time. I understand that air escapes through the tube. Possibly some leaks through the valve too? In any case, do tire / tube / valve combinations exist that will maintain a constant pressure over time?

Edit: From reading How long should a road tyre hold its pressure? I learn that air leaks through the tube material. I've changed the title in response - it originally applied to values only.

You assume the whole leak is the valve.  Rubber is not air tight.  Most of the leak is through the rubber.

Clearly can create a near airtight valve.  And with enough rubber a near air tight tube.  But it would be heavy.  Just pump your tires once a week.  I see the link said pump daily.  OK, at least once a week.  On my road bike I pump before every ride.


Can hanger extender be used as replaceable hanger? One advantage of replaceable hanger for rear derailleur is that you can replace it (opposite to fixed hanger). I have fixed hanger (or fixed frame) and although it is a steel frame I started wondering if I could add hanger extender as a protection tool.

One point I can see it might fail to protect anything that extender is pretty short (comparing to hanger), it is more solid and there is no really a point where it could bend.

So would it be an overkill (over-protection) and it won't protect anything or is it actually a good idea?

I doubt it. There is a good chance that the extender is sturdier than the fixed derailleur hanger, in which case it would add leverage, making a bent or broken hanger even more likely.