How does stiffness in carbon frames increase speed? I have a Specialized Roubaix with a 7r carbon frame; the Tarmac has 11r. Will I notice a speed change if I ride "exactly" under the same conditions? Does the additional 4r = more speed? I am thinking in upgrading but I dont want to make the investment without some good feedback.

General rule of thumb, a stiffer frame will absorb less of the input energy and transfer more energy - hence more power from you legs means more power to the wheel.

But....

The bikes have different designs, so the aerodynamics of the bikes and the rider on them will be different which will result in different speeds.

And then...

A stiff frame will transmit the road imperfections into the rider causing fatigue and causing the rider to expend more energy because the bike/rider is being lifted up by road imperfections where as the more flexible bike will absorb them meaning the bulk of the mass is moving forwards.

An ideal bike is stiff where it needs to transmit peddling force, but has shock absorbent qualities to absorb bumps and road imperfections while being aerodynamic for both bike and rider.


Mystery puncture -- caused by inner end of ice spike? I had to change my back tube yesterday and couldn't find anything by eye or by feel on the inside of the tyre, by eye on the outside (it's a schwalbe winter so you can't find anything except its own spikes by running it through your hands). The rim and rim tape were also clean.

Several of the spike bases showed signs of wear on the inside of the tyre, in one case there were threads showing.  By the time I found that I'd taken the tube out, so I just covered it and put a new tube in.

I haven't yet patched the tube (I do them in batches to save the glue drying up on the shelf) but there was no visible damage (or hissing with everything still on the bike).  The tyre had held pressure for a week before feeling low on Saturday and being confirmed on Sunday, so I'm not inclined to blame grit in the valve.

The tyres only have ~1000km on them, last winter and some of this winter.  They've lost a few studs but the tread looks as new.  They've only been used on tarmac (a few spots on my route are prone to black ice).  They've also only been run close to the max pressure, as recommended for hard surfaces.

I'd be happy to dismiss it as bad luck, but if this is an issue I'll fit tyre liners next time I mount these tyres

So: Can the inner end of ice spikes wear through the casing to cause punctures?

The conclusion from the comments was that this is possible -- possibly the threads abrading the tube.  To be on the safe side I'll cover that point with a patch or liner next winter.


What are the most important things to bring on a ride? On one of my recent ride, my bike broke down. My rear derailleur got pushed into the rims and broke. Since I have never gotten stuck like that before, I've never bothered to take anything with me other than food and drink.  I am not too proud to say I was stupid to do so. Since then, I've been searching for the things I should have on any sort of ride.

I found some good resources, but I was hoping for a good resource on this website, but cannot find one. So, What are the most important things that every rider should carry?

(P.S. The answers would be better if they are categorized by type of ride e.g. road riding, touring, mountain biking, trail riding, etc)

A mobile phone. These days, irrespective of where you're riding, what you're riding and over what terrain or distance, there's no excuse for being deliberately out of contact. We can't guarantee being in an area of reception, but if you haven't got a phone you'll never know.

Additionally, a huge benefit of smart phones are the apps that can do more than just call for assistance. e.g. I have an app which lists all bike shops in London, with maps, reviews and opening hours. A couple of times I've been stuck in the middle of somewhere unfamiliar and in need (after the second puncture of the day without a second spare tube): fire up the app, where's the nearest open shop and then it can lead you there.


Vibrations in frame when pedaling Recently, when I pedal sufficiently hard, I begin to feel vibrations through the whole frame of the bike. They are not so strong as to make the bike un-ridable, but neither are they road chatter. I suspect this to be somehow related to my recent replacement of a tire (i.e. the whole tire, not just the tube), but am unsure exactly what is making the sound.

The bike is a 1973 Sekine road bike. The frame is original. The chain and freewheel have enough stretch in them that I'm planning to replace them both again soon. The rims are true, but I don't know their age (came with the bike).

There doesn't appear to be any contact between the wheel and the frame of the bike or the brake pads. There is a periodic grating sound which also starting after I replaced the tire. Possibly it is caused by the metal plate which sits between the freewheel and the hubs, but I am not certain of this (can't replicate it when I'm not sitting on the bike).

Anyway, this seems like a bad thing. I usually like to fix the bike myself, but I'm not sure what to fix in the this case. Any suggestions?

Well, it's hard to say from your description.  Is the vibration in time with the turning of the wheels, or much more rapid?

A vibration that's in time with the turning of the wheels may be a warped rim, a rim rubbing the brake pads, a tire that's not seated properly on the rim, etc.  (The fact that this occurred after changing the tire suggests that last possibility.)

A vibration that's much more rapid than the turning of the wheels is usually due to resonance in the frame.  You'll usually see this more often when going downhill at high speed -- the front wheel will suddenly begin vibrating violently, such that you fear losing control of the bike.  What's happening is that minor vibrations in the bike (or even just due to the road) found a resonance in the bike frame, and the vibration becomes self-reenforcing due to the way it causes the front wheel to twist.

I'd suggest first turning the bike over or hanging it somehow so you can spin the wheels freely.  Observe the wheels carefully, looking at the space between the rim and the brake pads.  Look for any change of distance as the wheel turns.  Some small amount (a millimeter or maybe two) is to be expected on a well-used bike, but any more is a problem.  Also, if the rim touches the brake pads, that's a problem.

Observe from the side and look to see whether the rim moves in and out (decreases or increases in diameter) in relation to the hub.  There should be no detectible motion in this direction.

Next look at the tire while the wheel is spinning.  Look straight on so you can see both sides of the tire as it spins, and see if either side bulges out at any point.  Then look from the side to see if at any point the tire seems to increase or decrease in diameter.  Again, a one or two mm variation in these dimensions is probably OK, but no more.

Also look at where the tire disappears behind the rim.  There is generally a ridge in the tire a few mm from the rim, and it should maintain a fairly constant distance from the rim edge as the tire rotates.

(Since your problem began after changing the tire, these tire checks are likely to reveal that the tire is not evenly installed on the rim.)

While you have the wheels off the ground, grasp each wheel near the rim and push back and forth sideways, feeling for any play in the bearings.  You should not feel any play.

Finally, set the bike back on the ground, grip the front brakes to lock the front wheel (leaving the rear brakes free), and push the bike forwards and backwards.  You should not be able to feel any play in the "headset" (the bearing where the fork turns).


What are these holes in my frame for? I have two threaded holes on the inside of my frame on my 2007 Stumpjumper FSR and I don't know what they are for.

Can anyone tell me why they're there?

That's the mount for the Flow Control valve on the Specialized AFR Shock.

The shocks with flow valves came stock on the higher end models of the 2007 Stumpjumper FSR like the Expert, Pro and the S-Works Carbon frame:


Bosch 400Wh battery first led only is flashing and refuses to charge On a long trip with a lot of wind my 400Wh battery went empty.When i tried to charge it at home it refuses to charge. The first of the five leds is flashing. Strange because in the manual is written 1,3,5 leds or 2,4 there is nothing about only the fisrt one. Any suggestions?

When you discharge a lithium-ion battery all the way you can run into serious problems. If the battery is relatively new it may be under warranty and an exchange would be your best bet.

The battery contains electronic circuitry designed to prevent a total discharge. If that circuitry fails the battery is ruined. If the internal voltage of the battery falls below a critical level this circuitry will NOT allow the battery to charge. Your charger's refusal to charge the battery indicates a problem with this circuitry.

If your other options don't work, and you can't exchange the battery for a new one, you can try putting the battery in your fridge (not the freezer) for an hour or so and see if that will help jump start it. Cool for an hour and try charging.

In my experience, once this happens to a battery it's well on it's way to being dead forever, even if you can recharge it once or twice.


mechanical disc brakes and bikes with internal cable routing One review of TRP Spyre that I read said the brakes didn't perform well until the reviewer installed compressionless-housing brake cable. Is that the general consensus?
Jagwire says their compressionless product is "Perfect for full-housing, high-performance bikes with mechanical disc or rim brakes".  Do I understand "full-housing" correctly to exclude bikes with internal bare-cable routing? If the bike has internal routing, would standard brake cable be the way to go, and if so, would TRP Spyre be a waste of money on such a bike?

All mechanical disc brakes should have compressionless. The total pad travel distance is something like a fifth or a tenth of what it would be with a rim brake. Any length change of the housing is amplified in terms of waste lever travel by the same amount. Spyres and Spykes are good brakes, but using spiral housing on them can create problems that a caliper design can never solve, especially with routing schemes that require tight bends. Tight bends make the problem worse with spiral because an air gap is opened up between the coils at the bends, which then eats up lever movement before braking force is applied to the rotor.
If spiral housing is used, the power loss it creates and lever movement it wastes will be worse the more of it there is. And, as above, many full housing, internally routed bikes have some tight bends. That's what the ad copy is getting at. There's nothing wrong with using compressionless on interrupted housing setups.
Compressionless took/is taking far longer than it should have to become the norm for mechanicals, and it is a little finicky and has to be installed right, but many bikes need it for the caliper to feel good regardless of what model it is.


New touring bike components I'm buying a new touring bike. I need an opinion on some of the parts.

Crankset: Shimano XT FC-M770
Cassette: Shimano XT CS-M770
Rear Derailleur: Shimano XT M772 SGS
Front Derailleur: Shimano XT M770 Top Swing 9sp Front Mech
Chain: Shimano Dura-Ace/XTR 7701 9 Speed Chain

Are these compatible with each other? I can get a good deal on these components.

I'm also looking for 9 speed compatible bar-end shifters. Any recommendations?

They are all compatible. Generally speaking, 9-speed Shimano mountain bike parts are compatible with one another without. If there's an exception to that rule, I've never seen it.

One thing you might want to check is that your frame will be compatible with your top swing front derailleur. It's fairly likely that your touring frame is set up for bottom pull. If it is, you're better off getting a bottom-pull derailleur. There may be a way to make it work, but if so it's out of my realm of experience. And if you're getting new parts anyway it's just easier not to mess with it.

As for the shifters, just make sure that they're compatible with a 9-speed shimano mountain bike derailleur. You won't get good shifting out of one that's designed for road derailleurs.

As far as opinions and/or suggestions about what brand or model to buy specifically, those are generally considered off-topic per the FAQ.


I can't extract sealed bearings out of the wheel I face the problem again of extracting the bearings, this time out of the wheel of my Giant XTC Advanced 29” 1.5 2017, Giant wheel system, hub OEM manufactured by Formula.

Once removed caps and cones the axle can be released freely (no hit, no pressure, all loose) and bearings appear uncovered at both sides but I can't use the axle to extract the bearings. Then I hit hard with the punch from inside out but they do not move a milimeter. I have a déjà vu and stop hitting.

Again: What am I missing?

UPDATE: Last picture. It seems to me, but not sure, that the box of the axle is here wider than the bearing and maybe there is a ring preventing the bearing to be extracted that side. Maybe a circlip again? Or anyway should both bearings be extracted by the disc side? Sounds weird, I'm just pondering.

The bearings are out! After cleaning and inspecting I realized my guess in the UPDATE was baseless. Again the punch didn't work, but feeling confident I tried with the thru axle and the bearings jumped. The question is now: Which is the orthodox and/or convenient way of extracting the bearings in this type of assembly? What is the best tool to use to hit the bearings from inside out? At first time I was reluctant to use the axle to avoid damaging the sealing of the bearing (which finally happened), considering my intention is to reuse them.


Is a 29.5 km/h average speed decent for a 90 km ride (on road) with an elevation of 1200 m? I have been riding about 150 km a week commuting and on the weekend. I frequently do rides over 80 km. I'm riding a carbon cyclocross (Ridkey x-fire) with slicks.

My latest ride was on the Central Coast, New South Wales, in a very hilly area. I rode 90 km with an elevation of 1200 m with an average of 29.5 km/h. Would I be able to join a group ride and not get dropped?

Will switching to a dedicated road bike make much difference to my average speed? I feel like my setup is good enough, and I frequently pass other riders on their high end roadies.

Riding at 30kph average for 3 hours, in a hilly area is a solid effort.  Assuming your pack riding skills are sufficient, you will also likely do fine in in a club ride that averages 30-40kph (but see the pack riding primer below). Club rides will have a faster pace than what you are riding now, but you will also be working a lot less (about 30% less) at any given speed because of drafting.

Now of course this assumes your listed average speed is an honest average speed. That is you started your timer, rode 90 km, then stopped the timer and found you averaged 29.5 kph.  If by "average" you mean when you took the time to look at your speedometer you were often doing 29.5kph, then it is harder to assess.

Short primer on pack riding.

It is hard to give a definitive whether or not you will be dropped because solo riding and pack riding are very different disciplines and club rides also come in many different forms, from very competitive "A" group training rides with a drop policy (i.e., you are essentially on your own if you get tired or get a flat - very advanced groups), to others focused on sustained pace (what you likely do now) with no-drop policies.  If you join a no-drop ride, then the answer should be "no, you will not be dropped."

Riding in a "fast" group

Because you explicitly asked about getting dropped I will assume you are looking at joining one of the faster club rides that may have a drop policy.  In this case your pack riding skills will be just as important as your base fitness.  If you feel comfortable in a group you should have no problem holding tight to a wheel, where you can  will get a good draft and will be able to sustain higher speeds.  Riders that feel less comfortable will often allow big gaps to form or ride off the back to feel "safer."  This will require a lot more energy for a given speed.  You will also be able to read the pack, and keep a good drafting position as the group surges.  If you get taken by surprised in surges you can find yourself dropped quickly.

Assuming your pack handling skills are sufficient, riding in a fast group will also require two types of fitness, endurance fitness and peak output.  The endurance fitness is what you are doing right now and will help ensure you can put in an effort for 3-4 hour duration of the club ride. The peak output fitness will be important to handle pack surges.  Often competitive club rides will have sections where there is either an all out sprint or it is "common" knowledge the next x kilometres will be all out effort.

If all your milage has been at one consistent speed, then you might find these types of surges difficult to handle, even though your base endurance fitness is excellent.  If you find this happening, it isn't necessarily because you lack fitness, but you may simply not have all the right fitness components. Supplementing your distance training with interval training can go a long way.

Many novice riders make an number of tactical errors that make it harder to finish the ride.  A common mistake is try to take long, long, pulls to "prove" how strong they are.  Keep you pulls short (i.e., under a minute) to ensure you have lots of energy and don't build-up a lactate debt.  As you do more club rides you can start trying longer pulls if that is your thing.  Another common mistake is putting in too much effort, too early.  Many fast rides will do the hard efforts on out-and-back sections.  This means you can get temporarily dropped and catch back in as the group comes back from a hard effort. If you are unsure if you can sustain repeated high intensity intervals, it may be best to opt out of effort and catch back in after everyone has finished tearing each others legs off.  You would be surprised how refreshed you can feel by skipping an effort or two.

If you feel comfortable in a group, have no problem hold tight to a wheel and can sustain repeated bursts of speed, then you there is a good chance you that you can hold in on an advanced group ride.

Other Types of Group Rides

As eluded to earlier (and in other answers) not all club rides are created equal.  Some rides are focused on building base fitness and camaraderie.  These groups are usually focused on riding a consistent pace (no surges) and usually have a "no drop" policy. These types of rides are a great if you are new to pack riding.

Many clubs will also have multiple different rides on any given day so you can do some trial and error to find the one that best suits you.

I suggest chatting up your local clubs, ask about their club ride policies and see which one best jives with what you want to do.


My bike shifting won’t surpass 6 I own a Scott Aspect 740. On the shifter it says it is on gear 7, 8 or 9 however in reality on the rear derailleur the chain is only on 6 and won’t go past this.

I’m looking for a fix as it is very annoying having to change into say a 3 and a 4 rather than my preferred 2 and an 8 for downhill riding.

It sounds like your derailleur cable has a bit of slack in it. You will find this video useful, its easier to give you this link with a lot of good footage than try to explain it myself.


How do I know when to replace my bottom bracket? With out completely removing the cranks and bottom bracket, how can I tell when it's time to replace my bottom bracket?

The current symptom is a slightly 'rough' feeling when I pedal. It's not constant, and it's not the pedals - I've swapped them out recently with nearly new ones.

Pull your cranks laterally. Do they
move?
Give your cranks a good spin,
preferably without the chain. Hear
any unusual grinding noise or little
clicks ?

If you answered no to both questions, keep pedalling. You're still fine.

It would be nice if the BB was always smooth as butter, but a little rough doesn't mean it's broken.


How can I protect cables in inclement weather? I cycle year round, in Maine. It is pretty much guaranteed my brakes and shifter cables will need replacement in the spring, even if I try to maintain and clean the bike after each ride.  Does anyone have any tips or tricks for protecting cables?

(The road salt, or whatever it is, seems to kill the cables, and yeah, I totally remember a time when cables would last a couple seasons, before the advent of what ever is going on the roads now.)

I wrenched for a cyclocross team and those bikes see pretty torrential conditions. How are you cleaning the cables? If you're just cleaning them as they are on the bike it probably won't do much good. You need to take the housing out of its stops.

How to do this:
Rear derailleur: Shift your bike into the largest/inner rear cog. Now WITHOUT turning the crank click the shifter as if you were shifting into the smallest/outer rear cog. This will create slack in the cable and you'll be able to easily pop the housing out of its stops.
Front derailleur: Shift into the big ring. Now WITHOUT turning the crank click the shifter as if shifting into the inner/smaller ring. Again, you create slack and be able to pop the housing from its stops.
Brakes: You need to release the brakes. On a side pull there is usually a quick release lever on the caliper itself. On cantilevers you need to unhook one end of the straddle cable. Again, this puts slack in the lines and you can pop the housing out.

Once you have the housing free of its stops you can slide it to one end of the cable and wipe down the cable then slide it back to the other end and wipe the remaining cable.

It only takes a minute or two to do this. Do it after every wet/muddy ride and cables should last all season.

The more extreme and effective solution is to run full length cable housing. Basically if you have non stop housing from brake/shift lever all the way to the derailleur/brake there won't be as many points for grit to enter. This is how all bikes used to be but in the 80s everyone went to split stops because it was cheaper for manufacturers and also because more housing means more housing compression and that means spongier brakes and less precise shifting. Modern housing is much better than the stuff from 30 years ago so that need is no longer as great. Thanks to the rise of hydraulic brakes there are now little adapters designed to plug into the split cable stops to hold hydraulic lines in place. These same adapters can be used to hold full length housing in place and I've seen guys use them for the rear brake and derailleur cables on cross bikes. Here's an example: http://problemsolversbike.com/products/housing_guides


Can I lace a XTR rear hub with thirty two spokes from a Valiant asymmetrical rim to a thirty two hole Magic regular rim? Can I lace a XTR rear hub with thirty two spokes from a Valiant asymmetrical rim to a thirty two hole Magic regular rim?

Yes. The hub doesn't really care whether its spokes are laced to an asymmetric rim or not.

However, you may not be able to reuse the spokes--regardless of whether you're switching between an asymmetric rim and a "straight" rim, the spoke lengths may well not be close enough because of different rim depths. You'll need to check a spoke-length calculator.


Restoration and upgrading old bike I have an old Huffy from my uncle that he bought at around the 90s and I'm thinking of restoring it and maybe upgrade some of the parts. But Huffy doesn't seem to have any much information for bikes over 10yrs old. Here's a photo of the bike.

Obviously, I need to strip the paint of rust that's accumulated and clean it. But I'd like to know what I can do to see if any current generation parts I could use. I'm planning to convert this into a commuter or maybe a road bike (not to be raced). I would guess that I need to replace the whole drivetrain. Maybe fit in 700c wheels or something similar? Brakes need replacing as well, since it used old caliper brakes, I'm guessing that I can use some modern brakes? I suppose the headtube needs some work as well. Basically, I'm only planning to keep the frame and the fork.

Hoping somebody could help.

If you really want to use that bike, the best thing to do is fit the cheapest components that will make it go (and stop), clean off the worst of the rust and use car touch-up paint to cover the bare spots. You might want more than the cheapest of the cheap for brake pads, especially if the rims are chromed steel and you're not in a desert.  Unfortunately before you can really test anything you'll need tubes and tyres.

Then you've got an ugly bike that's good for not getting stolen, and won't lose value because it hasn't got any (not even all the value of the components you fitted new).  That also makes it good for leaving out in all weathers, though  it won't last forever. If you've got spares from another bike, it's much more worthwhile. I ride an early 90s bike only a little better than this for a few miles a day, and lock it in not the best places, so I assume it will get stolen/vandalised.  Despite having spare new tyres to fit, I spent almost as much on essential components as you could spend on the cheapest bike in a cheap bike shop, and what I ended up with was only a little better (mostly tougher).  When you've run it into the ground, save the components you fitted for use on the next bike, and recycle the rest.

If you've got major rust, espcially on anything critical, walk away.

One of the worst money pits on a bike is trying to change the wheel size, with only a few exceptions.

This may sound harsh but it's the only way to avoid throwing good money after bad.


What is the reference unit of the kgf reading on the Park spoke tension chart? What is the reference unit  of the kgf reading on the Park spoke tension chart?  Is it kgf/cm?

Kilograms force. It is tension equal to a weight of that many kilograms pulling on the spoke under earth gravity.


Extra power needed uphill for weight increase How much does weight mean when going uphill?

Let's say I'm going up a mountain with 1000 m of elevation and it's quite steep: 10%. Let's also say I can maintain 250 watts. If I add 1 kg of weight to the bike, can I determine how much slower (in time) I will be? How many seconds will I lose?

Please show me the formula and calculation of this, and feel free to elaborate on the whole subject.

Presuming you are doing a standing start and coming to a complete stop at the top of the hill.  The simple requirement is you need energy to move your from the bottom to the top.  Most of the energy required will be to raise potential energy of the payload (you and the bike).  Essentially you will be creating kinetic energy (moving the bike) by converting chemical energy in your body.  There will be loses due to heat, friction with the road surface and air resistance.

Disregarding them for the moment (they are not negligible, but complicate the calculation).

Potential Energy (PE) = m * g * h

Where:

m = mass

g = gravitational acceleration

h = height

PE is proportional to m, so a 10% increase in mass will increase the PE by 10%.  Meaning you will need 10% more kinetic energy to get to the top of the same hill.

Power is work done (energy) divided by time:

P = W / t

Where:

P = Power in watts

W = work done or energy in Joules

t = time to do work.

If your power is constant we can rearrange the equation to get

P = (m * g * h)/ t

becomes:

t = (m * g * h) / P

so with constant power, gravity and hill height your time will increase proportional to increase in mass, given by the above equation.

If there is no wind air resistance will become less relevant the slower you are going.  Friction will increase due to increase in weight.  The steepness of the hill is theoretically irrelevant in this calculation.  You are gaining the same amount of Gravitation Potential energy when you the same mass to the same height.  So it shouldn't theoretically matter whether the hill is 10% or double as long and 5%.

However, as you are generating the energy you need to create it from chemical energy, and there is only so much you can generate at one time.  Your muscles will become inefficient and therefore on steeper hills you may require more energy than less steep ones.  So on a steeper hill wind resistance might become less relevant but power (how much energy you can put out over time) to weight ratio will become the most relevant factor.

What I am trying to point out in the last paragraph is that the energy you require to put into your body and for your body to convert into forward motion is not the same as the simple kinetic energy required to get you to the top of the hill.  However all things being equal a change in mass will have the same affect on the time as I stated in the equations.


Why does reducing bike weight have such an impact on speeds? I am trying to understand the physics of bike weight.  I have just made a switch from an 11Kg road bike to an 8Kg one (obviously there are many more factors and differences between the 2 bikes other than weight), and have noticed the benefit of reduced weight.  However I am not sure I understand it.

Let's say for example My combined weight is 8+75 for a total weight of 83Kg.  The difference between this and 86Kg is minimal, but is does make a difference seemingly beyond what I would expect.

Assuming I could equalise the total weight by carrying a pack or particularly heavy bidon/saddle pack) such that the combined weight could be the same, why is the lighter bike always seemingly faster?

I have read something about rotational mass, which seems to indicate that it's nothing to do so much with your combined weight as perceived through gravity, but with the equivalent lifting effort of the moving parts, namely your wheels, and in fact it's wheel weight that is the major factor because your are in effect having to lift half the wheel in order to produce forward momentum.  Is this a sort of gyroscopic affect whereby the easier it is to turn your wheel the faster you go?

The two major "drags" on a bike, on level ground, are the rolling resistance of the tires and the wind resistance of the bike and rider.

In general, up to a point, a tire with higher pressure will have lower rolling resistance, as will a tire with a smoother tread.  Tire width also figures in, but mostly in terms of how it influences pressure and tread.

Wind resistance is affected by tire width, number of spokes, tube size, and rider position.  Generally, as the "raciness" of a bike increases, tire width and spoke count decrease and rider position becomes more prone (and hence more aerodynamic).  Tube size doesn't tend to vary much (and may actually increase as you go steel->aluminum->carbon) but that effect is slight and subtle differences in frame design can be more significant.

There may also be ergonomic changes -- eg, the more prone riding position, while more fatiguing, is often somewhat better for peak power output.

Bearing quality hardly figures in at all.  Even cheapo bearings have very low losses, and the difference in drag between them and top-of-the-line bearings is not likely to be measurable.  (The bigger difference is in durability.)

Bike weight only comes into the equation when one must "climb" (and to a very minor degree for rolling resistance), but of course it's rare to have a route that does not go up/down by 0.5% or so most of the time.  That 0.5% increases the power required to hold a steady speed by about 10% over a dead-level course.  But the 3KG difference between the above two bikes would amount to about a 0.4% power difference on that 0.5% slope.


What's the best way to repair a small hole in a tubeless mountain bike tire? I've seen some youtube videos but not sure which method is best.

At home? On the trail? How big a hole?
If it’s around 5mm or less you can use a “bacon strip” tubeless plug. If it’s larger you are probably going to want to glue a patch to the inside of the tire. Proprietary plug systems are similar to bacon strips for utility just quicker & more expensive. A plug of any kind can be considered a forever fix.
Sidewall slash? You might be lucky by sewing the cut with dental floss and then patching from the inside but also be prepared to let it go and buy a new tire. Your risk vs cost calculation is your own. I don’t want to be stuck 20km from home with an unusable tire.


How to ride to work without sweating? I'm planning on commuting by bicycle to work in hot Montreal, though this question is probably relevant to anyone who bikes to work in a city with temperatures above 20 degrees Celsius (68 degrees Fahrenheit). I have to wear business casual to formal clothes (no jacket, usually).

How do I not sweat?

I'm particularly looking for

Helmet features that prevent sweating
Tips on rhythm, speed, pace, etc. that prevent sweating
Bags that will make me sweat less (I'm leaning toward nice, office-friendly panniers at the moment but I'm open to other suggestions)

Any other tips would be greatly appreciated.

It is possible, but only in certain conditions. I live in a tropical country, so, 20 degrees centigrade is considered cold here. My conmute to work is almost flat, with only one climb, something a very steep 300 meters. If it were not for that, I'd be able to get to the office almost completely dry.

What's the trick? I use a hardtail mountain bike with a small rack in the seatpost. The bike has a sporty position, but the trick is to pedal in the easy gears and making very little effort, accelerating very slowly. The effort should feel comparable to a moderate walk. Also, take as much advantage as I can from the downhills (Update: later on, I changed the tires to slick ones, that reduces the effort needed to move).

However, ideal conditions are an exception. I have already told you that I have to climb a very steep hill, so I just put the easiest gear and pedal like a grandmother for that hill (While in "sports mode" I can climb the same hill in 4 gears higher and a quarter of the time). I sweat the minimum and I manage to avoid clothes changes, but there are other things I do to minimize body odor:

Drink more water than actually necessary: urine then turns colorless which is a practical indication that the urinary system has got rid of most waste substances. This helps because some of these substances make their way into sweat and contribute to body odor. The practical point is that even if you sweat, it won't stink that much. *(1, 2, 3)
Apply a little deodorant in other parts of the body besides armpits. (I recommend a little in the chest and in the back)
Carry a clean hand towel and use it to dry the sweat when you get to the workplace. First the face, then the hair, then the neck, arms and last, armpits. This helps because part of body odor is caused by bacteria(2) that reproduce and feed in the warm, humid environment provided by the sweaty body, so cutting the time the humidity lasts reduce the growing of bacteria. The towel can be pre-scented with a suitable cologne if you want. Rinse the towel thoroughly and twist dry it as much as you can. It won't be smelly if you do it right, so you can discretely hang-dry it near your desk without disturbing anyone.
Leave home early enough so you can take your time getting to the office, also, plan to get there 20-15 minutes prior to the time you have to be there, so you can spend those "cooling off". Sprinkle your face with fresh water, moisten hair (and apply hair gel, if you use to do so) which help against "helmet hair".
Avoid carrying backpacks or anything similar. Any strap that makes your clothing tight against your upper body will wrinkle the clothes, will restrict airflow around your torso, preventing sweat evaporation thus avoiding its cooling effect(1), so it will make you sweat more. They will also cause curious sweat marks in your shirt.

All those tips are easy to implement, and can keep you from needing to change clothes. After you cool off and clean yourself with the towel, most people won't even notice a difference on you if you hadn't commuted by bike.

As per anecdotal stuff, my grandfather used to commte exclusively by bike, in a small city located in the Valley of Sula (Valle de Sula) near the city of San Pedro Sula in Honduras. A valley in a tropical country has a very hot weather all year round. He used a bike similar to the "Flying Pigeon" (Google Flying Pigeon Bike for images). That is a heavy steel bike with 28" wheels, a very high gearing and a very comfortable seating position. I remember that he was never sweaty, even if he commuted from workplace to his home for lunch, right under caribean sun at noon. Two elements had a big role in it: 1) the city is completely flat, no climbs, no downhills. 2) The bike he used is almost impossible to pedal in an sporty way, it kind of 'forced' you to pedal in a smooth fashion, with slow cadence, but after a while, you get some speed that is really easy to keep. It makes you feel you can go for hours without getting tired.

(1) Perspiration (Wikipeia)

(2) Body odor (Wikipedia)

(3) Urinary system (Wikipedia)


Guidelines for building tape delimited MTB courses There are a few vacant lots around where I live and last weekend, I built a small (170m) tape delimited course.

Some of the kids in the neighborhood rode in it. I also worked out in it, going full tilt for 30 minutes (ie. 36 laps in 30min, 6.2km). Some portions were up a grade, others went down a grade. There were a few areas that were quite tight to turn around in, but otherwise, it seemed alright. This lead me to search for possible standards in this area.

I was wondering if there were guidelines or standards for building such courses in terms of lane width, turning areas and such?

Edit #1

Here's what our course looked like:

The corner in this image was quite hard for everyone - which could just be testament for our skill level :)

The goal isn't to be a UCI event, just looking to give my kids some more experience riding.

Yes. Have a look at UCI's MTB rules at http://www.uci.ch/mm/Document/News/Rulesandregulation/16/72/76/MTBReglementsENG_English.pdf

Look for "course marking".


Securing bikes while on a car hitch mount I've recently come into ownership of two very nice bikes. I live in an okay area, so I haven't had to worry about bike security very often.

We do, however, often take our bikes to less than savory areas - we have a Thule T2 Pro and often stop for lunch ~wherever~.

What is the most reasonable way to secure our bikes from theft? I understand that no security is perfect. (If you see my profile, most of my rep is form Security.SE /humblebrag)

Presently we do this - this is assuming a worst case, run down terrible area, with a bike chop shop next door to where we park, etc etc.

1) Avoid parking in such areas.

2) Stay with the bikes if at all possible.

3) Bikes are attached to the Thule T2 Pro using the built in cable locks - it connects the front wheel and frame to the rack. The T2 Pro can be firmly attached to the trailer hitch using an expansion screw included in the design of the rack.

We are also considering adding the following:

1) A cable lock threaded through the seat, frame, and rear wheel, to complement the front cable.

2) Locking the bikes together using a flexible plate-link lock.

Neither of these are absurdly harder to implement, and avoid some, but not all, piece-meal theft.

EDIT: The T2 can be attached to the car in such a way that it can't be removed without the key, or spending some time 'hacking' the locking mechanism in one way or another. This post originally didn't say that and some comments will be confusing due to this.

My preference for my hitch rack security is to use a 5 foot Schlage 999478 High Security Chain with Cinch Ring to pass through the frame(s) and use with a long kryptonite evolution U-lock to secure the chain and my bikes to my hitch rack, which is secured to my car with a locking hitch pin. I also will incorporate a separate cable lock to secure my wheels (I just use a loop style and thread it through the ulock as well).

I figure this way, if anyone wants to steal my fancy mountain bike, they at least probably need power tools to easily steal my bike. I prefer this method so I can more safely leave my bikes unattended for short periods while on road trips or during after ride beer stops.

My opinion is a cable lock is about as good of security as a strong rope. Any yahoo can buy a pair of wire cutters at a dollar store for $3 and steal your bike in a minute or so if you rely only on cables.

However, the folding plate lock is a bit higher security. I also use one of these on my commuter and would trust it for a medium level of security where I'm leaving the bike unattended for a bit. Maybe not in NYC, but in the smaller city I'm from, I trust it about as much as a U-lock.


Why some companies stop supplying frames to pro teams? Nowadays TIME hardly sponsors professional cycling teams at least with their frames, and I feel others like LOOK, De Rosa or Cervélo are also leaning away from it.

Why it happens? Do they think their reputations are already established enough and thus they don't need to promote and advertise products anymore? Or are they running out of money and can't afford to offer teams a better deal than others? Or the quality of their frame are actually inferior and they don't want to let people be aware of it?

Having nothing against companies like Specialized or Canyon, but I kinda feel sad to see multiple teams share the same bike.

You have it backwards. You seem to think pro bike teams are looking to purchase frames from suppliers, and all the supplier needs to do is offer a decent discount. It's the other way around - most pro-tour bike teams require payment from the supplier if they are to display decals, and needless to say the gear will have to be supplied without cost.

You will often see a rider on a certain team has insisted on bringing his favorite saddle, which will then have all decals and logs removed if the supplier doesn't want to pay, or the team already has a primary supplier for that part. You will also see them removing logos from tubular tires made specifically for the cobbles, where most the big-shop tire sponsors do not have a suitable tire. As well, you may even see a team using old frames from a competing brand for a cobble stage where the current frame sponsor did not supply a suitable frame - in this case, the frame will either be rebranded or have branding removed.

In short, I think the lack of diversity you see is more a fault of the sport and the economics of it, not the fault of niche frame manufactures. Big high-revenue bike companies can afford to bet on multiple teams, while betting on one team may be a too risky proposition for a niche player (especially a team they can afford to sponsor).


Concerns with different brake types for the front and the rear wheel I'm considering adding a disc fork to my surly cross check and using some avid bb7 road brakes for the front. I've got tektro road levers on drop bars (outfitted with retroshift shifters)  I've got all the gear, so cost is negligible.  The frame is not built for disc brakes, so I would leave my cantilever brakes on the rear.

I know the modulation and grab will be different for the brakes.  Should I be concerned about having different types of brakes on this bike?

Quick answer: Don't worry.

Front and rear are already "functionally different" on two-wheeled vehicles, to the point that we have different tread patterns and even wheel sizes (at least in motorcycles this is common-practice).

So, having brakes with different "feels" is not a problem by itself, unless this bothers you, or makes you over/underestimate breaking power due to a possibly stark difference.

Hope this helps!


Do I need a shock-proof watch for cycling? I've just started cycling longer distances as a hobby (I cycle for my commute daily).

My watch isn't waterproof at all so I don't take it with me but on my last ride I found myself getting annoyed at regularly having to rummage in my bag for my phone to check what time it was.

I don't want a fancy GPS or sports watch that measures anything except time.

Obviously it would need to be waterproof enough for heavy rain (100m+? 30m?).

Would a simple digital (no moving parts to dislodge on a rough road) waterproof watch do the job or does it need to be shock proof (ie. G-Shock or similar) as well?

There are no special requirements for a watch for cycling. A cheap watch from the supermarkt will do as well as a decent quality watch or a sports watch (besides sport-specific functions).

Rain or road buzz might damage rather sensitive watches. Fixing a defect, loading the bike, or a crash also gives opportunities to damage a watch. Common sense will suffice to know when to take your horological masterpiece or leave it at home. In other words, there's a difference between riding to an opera and doing sports.

Most mechanical watches, for example a Seiko or something with an ETA movement, shouldn't be troubled by road buzz or the occasional cobble stretch. Please check reasonable voices in a watch forum.

Much sports riding is on a different level of impact, vibration, and risk of damage. In other words, mechanical watches are perhaps not the best choice for downhill MTB. A decent quartz watch or a G-Shock (analogue or digital doesn't matter) are preferable. Still, a dollar store digital will perform as well as the G.


Can I run rim brakes on a disc rim? I'm trying to buy a front wheel which will work with both disc and rim brakes so that I can use it on my cross bike (with rim brakes) and my mountain bike (with disc brakes) with a dynamo hub to power lights for night riding.

Can I use a disc rim with rim brakes (cantilever or caliper) or will I need to buy a wheel that does not have a disc specific rim?

Some disc-brake specific wheels use rims that are not designed for rim brakes. To accomplish what you want you need a wheel with a a disc-brake hub and a rim-brake rim.

With that setup, assuming the fork widths are the same, you should be able to switch wheels between bikes without problems. The only drawback is the slight increase in rotating mass from having extra material in both the hub and the rim.

An example would be this wheel from Mavic available at Nasbar, but your LBS should be able to easily build up wheels for you if they don't have something specific in stock.

To use your dynamo I think you are forced to have custom built wheels, but it should still work fine.


Examples of disc brakes causing injury in pro races Before disc brakes became UCI legal there was a lot of people arguing that they were more dangerous than standard v brakes in bunch races. Often it was highlighted that a very hot spinning metal disc could slice through skin or tissue very easily.
Discs have now been in pro and local races for quite a while - I was wondering if there were any examples of this actually happening?
Cheers

Reports are becoming more common:
https://www.cyclingweekly.com/news/cyclocross-rider-hospitalised-after-disc-brake-causes-wound-484217


What make is my BMX frame? I have a BMX forsale, but I would like to know what make the frame is so I can determine how much it is worth.
Does anyone recognise this symbol on the frame?

Thanks for your help
Jon

The bike is one of the Haro Nyquist siganture models. There were a few different models and years so you would need to get the serial number and deciper from BMX Museum Haro Serial Number Info

For instance if the S/N starts with R24W5.... it will be a 2005 Haro R24 Nyquist.


How tight should cycling shoes be? Ski boots are notoriously difficult to fit. The fitters will advise to go one and often two sizes down from what would at first seem like a comfortable fit.
Do you find any performance advantages from wearing tighter clipless cycling shoes? The sizes on Shimano shoes seem to be one to two sizes too small from what one would expect. Is the reason for that that they are meant to fit (very) tight?
Update: socks
Companion question: What is the thickness of the socks you wear with cycling shoes? I imagine cotton is a bad idea in an intense (i.e. sweaty) workout. Polyester or wool are the only two options (moisture wicking, less hospitable to bacteria growth, etc). Wool would not help much with guarding against cooler temperatures, 1- because wool socks are usually so thick they'd require a different size of shoes, 2- because the shoes are ventilated and so the inflow of cool air will anyway negate the advantage of wool. Hence polyester is the only option.
Can you confirm in your answer that the thinking above is accurate, that cycling shoes are worn with polyester socks. These, I assume, would not modulate temperature. The socks one would wear would remain on the thin side. One would modulate the temperature by full leg covers (and shoe coats if/when necessary).
Briefly: Can you comment on the thickness of socks that one would typically wear during summer? Does it boil down to preference? Some people wear soccer shoes with extra thick socks and others with thinner socks. Does the same apply to clipless cycling shoes, or does everyone eventually find that thin or thick socks are the way to go?

In my experience you mainly want them to be comfortable.

But there are several considerations:

If the shoes are too short your toes will bump the ends, and this can become torturous 75 mile into a centurion.

On the other hand, if the shoes are loose your feet will slide back and forth.  Not only can this be painful, but it means that you will not have a steady foot on the pedal, but rather the relationship between the ball of your foot and the pedal's center will be constantly changing, resulting in poor pedaling (and some additional pain in the foot).


What is the cheapest and easiest way to add a power meter to my Diamondback Haanjo 4? What is the cheapest and easiest way to add a power meter to my Diamondback Haanjo 4? It has a Praxis M30 BB and a Praxis Alba crankset. Thanks!

I was going to say that you should send the left crank arm into 4iiii to install the strain gauges. They charge US $300.

However, I checked, and they do not list the Alba as eligible for this service. The reason likely has to do with economics. All power meters use strain gauges to determine how much you are flexing the crank arm (it’s more complicated than that because the gauges need to isolate the amount of flex in one dimension, but bear with me). Beyond that, however, a power meter company needs to determine how much the crank deflects under a set amount of torque. All cranksets have different wall thicknesses and materials, so all will deflect a different amount for the same amount of force. In theory, I see no reason the Albas can't take strain gauges. However, they're entry-level cranks. If you could convince 4iiii or Stages to do the calibrations, you could get either company to do the factory install, but they are likely to judge that the demand for Albas with power meters is too small.

Shimano 105 through Dura Ace cranks are all very common, so it’s clearly worth it for power meter manufacturers to validate their meters on all those cranksets. Campagnolo is a much less frequent groupset choice, so companies may only support some models, e.g. 4iiii only supports Potenza, Record, and Super Record, leaving Chorus, Centaur, and everything below out.

Praxis is a much smaller brand. 4iiii supports the carbon Zayante cranks, but not the Albas. Stages doesn’t support them at all. Pioneer, while they sold power meters, only supported Shimano cranks.

There are some options. I believe that some versions of the Alba have removable spiders, and Power2Max should make a spider-based power meter compatible with this crankset. You could buy a Zayante crankset with a power meter pre installed. Especially if you already use Look road pedals, you could buy pedal-based power meters instead; of the available ones, the Favero Assioma appears the cheapest and it is also very well-regraded. All these come in cheaper single sided variants as well as dual sided.

Sadly, you will need to change your bottom bracket to use Shimano cranks or a BB30 crank with power to your bike. The M30 Bottom bracket has a 30mm spindle that tapers to 28mm on the non-drive side, whereas BB30 is 30mm throughout, and Shimano is 24mm throughout. Changing the bottom bracket would make switching cranks more expensive.


Fixing damage to brake rim surface somehow the alloy braking surface of my rear wheel's rim has got a series of quite shallow lacerations, less than a mil' deep bunched quite closely together (the effected area is no more than 1/8 of the rim).

When I brake (side pull road bike brakes) I can hear it making a different sound on each rotation has the damage goes past the pads.

The wheels are Reparto Corse's which came with my Bianchi, they are new and have less than 1k miles (probably way less). And they are fine in every other respect.

So I guess my options are:

Leave it and let it smooth out with use. May take some time and wear down brake pads faster.
Lightly sand the worst offending parts with high grit abrasive paper.
Fill the damage with expoxy (or similar) then sand.
Replace the rim (would it worth the labour cost?)

So are any of these good options or do you have any idea what you may also do?

Thanks

You've hit the major repair options in your question. I've heard of people filling in spots on a fork stanchion before and having it work OK, so I'd assume a rim would probably work too. The only difference might come from when the rim heats up due to braking, the filler could expand/contract differently than the rim material and get dislodged again.

I wouldn't recommend sanding as removing more material will make the braking surface uneven anyways. If it were me, I'd leave the damage as is and only address it if it starts to cause the brake pads to wear very quickly.


Why are regenerative brakes uncommon on e-bikes? Few electric bicycles have regenerative braking. Most quality e-bikes seem to be settling on mid-drive, which even makes regenerative braking impossible because there is a freewheel between the wheel and the drive, and the rear derailleur as the chain tensioner!
Why is this the case?  Why are regenerative brakes rare?

There are several reasons for regenerative brakes not being common on bicycles unlike in electric cars:

Electric bicycles have very poor acceleration, and the rider produces about half of the acceleration with the motor producing the rest. The power is limited by the low-speed motor, not the battery. Most quality electric motors like to spin at 5000 - 20000 RPM, but in e-bikes they do not spin at any such speed range. The best RPM situation in electric bikes is in mid-drive bikes that have enough space to use reduction gears, and the mid-drive arrangement does not allow regenerative braking due to the freewheel. The worst RPM situation in electric bikes (lowest RPM) is in hub motors, the only arrangement that would make regenerative braking possible. These hub motors cannot produce high forwards torque, and therefore, cannot produce high inverse torque for braking. In contrast, electric cars are well-known for their high acceleration, thus allowing rapid braking. An electric bicycle with regenerative braking could produce only half of its poor acceleration as braking force, and it is not at all significant.

A common use case for regenerative braking in electric cars is going downhill. Most car drivers drive always very near the speed limit (unless traffic condition or safety requires otherwise). In contrast, most bicyclists ride at a very low speed that could be much higher. A car driver going downhill needs to brake to keep under the speed limit, whereas a bicyclist often uses a downhill as an opportunity for going fast. The most common braking at downhills for bicyclists is a 90-degree or hairpin turn after a downhill, and to maximize average speed, most bicyclists only brake very close to the turn, instead of braking all the time before the turn. Thus, a downhill is not a good location for an electric bicyclist to brake.

Another common use case for regenerative braking in electric cars is stopping at a red light. In contrast to cars where braking close to red lights instead of anticipating the traffic lights far away is common even for internal combustion engine cars lacking regenerative braking, most bicyclists have learned an energy-saving way of going through traffic lights, avoiding unnecessary accelerations to high speeds only to need to brake right away. While a regenerative brake could be useful for an electric bicyclist adopting a different rapid start - rapid stop riding style, most bicyclists do not consider such a riding style necessary.

The final killing blow making regenerative braking infeasible is the controlling of such brakes. In most cars, there is natural engine braking. Some electric or hybrid-electric cars (Toyota) simulate the typical engine braking amount with regenerative braking, while at the same time having complicated (expensive, heavy) machinery to adapt between regenerative braking and disc braking using the brake pedal. This approach has the advantage of familiarity for most automatic transmission car drivers. Such an expensive, complicated and heavy machine would not be acceptable on a bicycle. Other electric cars (Tesla) cheat somewhat and make the engine braking huge, to avoid having the complicated (expensive, heavy) machinery to adapt between regenerative braking and disc braking when the driver presses the brake pedal. In contrast, high-quality bicycles have extremely low rolling resistance and no engine braking -- there is a freewheel. The natural slight regenerative braking would be of no value in such a bicycle. The braking controls of a high-quality bicycle are independent levers for front and rear wheels. A regenerative brake would work on only one of those levers. Most of the time, the bicyclist uses the front brake only, and most quality hub motor electric bicycles are not front wheel drive for a good reason (when going uphill seated, the front wheel is practically unloaded and would slip). Even for a bicyclist that brakes with the rear brake, there would need to be complicated (expensive, heavy) machine to operate both the regenerative brake and the disc/rim brake with the same lever. Cyclists would not find such a piece of machinery acceptable. Thus, the only way to make regenerative braking possible would be to add a third regenerative brake only control working only for the rear brake. It would be a terrible brake due to the low torque of hub motor drive. Such a brake would be unused for most of the time.

Also, to produce useful torque at low weight, an electric motor needs to spin fast. The only arrangement making the drive motor spin fast on an e-bike is mid-drive, where the motor drives the bottom bracket through reduction gears. Such an arrangement does not work with regenerative brakes due to rear derailleur being the chain tensioner, and due to the freewheel in the rear wheel.
Because regenerative brakes have terribly low power (reason #1), no valid use case (reasons #2 and #3) and no feasible means of control (reason #4), and because mid-drive is the most logical drive variant in e-bikes that makes regenerative braking impossible, regenerative brakes are not feasible on e-bikes unlike they are in electric cars.


Are Avids BB7 superior to the Hayes Stroker Ryde? I know one is mechanical (BB7) and the other Hydraulic (Hayes)? but I have both and I need to decide. For a XC use, which would you keep?, and why?

PS: I'm upgrading from V-Brakes (Shimano XT group). So these will be my first Disc-Brakes.

As mattnz hinted at in the related question, not all hydraulic brakes are necessarily going to perform better than cable brakes, and it looks like you've hit that nail on the head with this comparison.

The Stroker Rydes are well known to be painfully poor quality. You would have absolutely no reason not to choose the BB7s in this case.


I need to get a new master link how can I tell the size of it? I have lost a piece of my master link for my bike is there a way to find out what size it is so I can order a new one and replace it.

Bike chains come in two sizes.   There's 1/8" chain for single speeds (bikes without a derailler) and 3/16" which is for geared bikes with a rear derailleur.

In addition you can get master links for 6/7/8 speed, or 9 speed or 10 speed or 11 speed.  So count the number of cogs in your rear cassette and go from there.

Master kinks are cheap.  Buy a couple, put a spare on each bike you ride.


What is the working mechanism of Shimano Power Modulator? How does the Shimano Power Modulator works?
Since there are at least 3 power modulators from Shimano, I refer to the SM-PM40, a little cylinder that runs on the front brake cable.
I never had the chance to open one ... I actually never tried one.

There appears to be a couple of things that Shimano calls 'Power Modulator'. I think the I think the basic idea of both is to prevent inexperienced riders from over-braking and losing control.

If you are talking about coaster brakes, it's basically a clutch which limits braking force. https://bike.shimano.com/en-EU/technologies/component/details/power-modulator.html

There is a mechanical disc brake version too which changes the lever ratio as the brakes are applied.  https://bike.shimano.com/en-EU/technologies/component/details/power-modulator-unit.html


New 26" inner tube different size to old 26" inner tube The new 26" MTB inner tube is much bigger than my 26" wheel (and old 26" MTB inner tube). I don't understand why. How to shopcorrectly for new tube?

The bike is 1990s Raleigh mountain bike.

Edit: the new tube is very loose both deflated and inflated. The new tube specs are 26 x 1.5 / 1.75 / 2.125 F/V according to the box and tyre

The old tube was 26 x 1.50 / 2.25 according to its box.

Check the label on the tube - does it say '26 x 1 3/8' by any chance? If so, this is actually a completely different size than the standard MTB 26". Get a tube that says something like 26x2.1 or 26x1.9 - the point is, the tire width should be expressed as a decimal, not a fraction. See Sheldon Brown's tire size chart.

Yeah, I know, it's stupid - I didn't come up with this system.


How to store a bicycle for an extended period of time? What's the best way to store a bicycle for an extended period of time, say 2 months?

Doesn't really matter.  Just try to avoid really wet places.  I have left bikes in the garage for years.  Or for months at a time between rides.  (Road bike during the winter, while I ride my MTB to work, and vica versa).

I have left them standing on the floor.  Hanging from both wheels in the ceiling.  I recall a thread on hanging from just the front wheel and consensus was it did not matter.


Can I fit a 32-622 tire on a 32-630 rim? Can I fit a 32-622 tire on a 32-630 rim?
The tire diameter is 8 mm smaller than the rim, so it's going to be tight - but will it fit with some extra force, and might there be any other problems?

No.

You would need to stretch the tire circumference by 25 mm for it to fit. If the tire has steel beads (cables at the edges) stretching them is theoretically if not practically possible but the rest of the tire structure is fabric that does not stretch.


What are the Pros/Cons of a 2.1 vs 2.3 wide Mountain Bike Tire Time for new Tires on my Mountain bike.

I'm currently running a 2.1 (26").

What are the benefits of the 2.3?

I'm guessing:

you can run it at lower pressure and get some of the benefits of a tubeless (more traction) with the downsides (increased rolling resistance)
higher weight.

From Tom J. Stokes excellent article on choosing tires:

Wider tires tend to grip better during cornering and over rough terrain, at the expense of increased rolling resistance and weight. Wider tires will also float better in sandy conditions and are much more resistant to pinch flats when riding over sharp rocks or off of drops. For moderately rocky cross-country use, the sweet spot is between 2.0″ and 2.3″. If you primarily ride smooth hardpack or travel at a leisurely pace, choose a 2.0″ or even a 1.8″ tire. Likewise, if you tend to corner hard on the downhill and ride rough terrain, lean toward a 2.3″ tire. For downhill mountain biking where pedaling efficiency is less of an issue, look for a tire between 2.3″ and 2.6″. Tires up to 3.0″ wide are available, but rolling resistance becomes very significant past 2.6″.
The front tire is typically subjected to more cornering forces than the rear tire. Likewise, the rear tire is usually loaded with more weight while pedaling. Consider using a wider tire in the front with a slightly narrower tire in the back to get the cornering benefits of a wider tire with the rolling resistance advantages of a narrower tire in the rear. I’ve had good luck with a 2.5″ tire up front with a 2.3″ tire in the rear on my downhill bike.
Also note that widths are approximate. I’ve got a 2.3″ tire which measures 2.5″ wide with my calipers, and a 2.4″ tire which is actually only 2.25″ wide. Make sure that your frame and fork have enough clearance to support the width of the tire. Maximum tire sizes are listed in the owner’s manual. If you ride through mud often, allow for even more tire clearance to keep mud from building up between the tire and frame.

Honestly though, the difference between a 2.1 and 2.3 is very small - I would just get the highest quality tire you can afford that is between those measurements.


Rear derailleur shifts all gears at once I've got Campagnolo Veloce gear system and I recently changed my worn-out rear cassette to a new one. Since then I've experienced issues when shifting to higher gears. When I shift, the cable moves all the way to its extreme position, or at least skips 3 cogs. Shifting to lower gears works just fine. This issue is likely not related to the pulley/cassette because I can feel the shifter releasing way too much even if the cable is not connected to rear derailleur.

I have done the indexing and H, L and B screw tuning. Do you have any suggestions how to fix this?

EDIT: The chains were also changed at the same time with the cassette.

Your problem is worn out (or broken) index springs aka G-springs. These are part of the shifter mechanism. Worn out G-springs will enable rear derailleur spring to pull the cable over the indexes.

One way to test is putting the rear derailleur on bigger sprocket and pull the cable. If it drops indexes (goes to smaller sprocket) then the problem is caused by G-springs.

G-springs are replaceable in older (pre 2007) Campagnolo shifters. Only tools needed are hex keys.


Lower limit screw for derailleur adjustment is already at its outer limit I have to adjust the gear shifting since the chain scratches at the front derailleur (at front smallest cog back largest cog). For this I have to turn the lower limit screw further out but it is already at its limit. What can I do to make the front derailleur screw adjustable again?
I have the Shimano GRX 810.

I assume you mean that it is rubbing on the inside, and that you want the FD to be closer to the bike. In this case it might be that you have cable tension causing problems. You should adjust the L screw without cable tension. You can simply loosen the cable bolt to help with this, so that only the L screw is adjusting the start position, not the cable
If there is still rubbing with no cable tension whatsoever, then it might be your FD is not straight (it needs to be rotated).
Review https://www.parktool.com/blog/repair-help/front-derailleur-adjustment
for steps.
Possibly also if your FD is not the original one you might have chainline issues, but you have not said here what bike you have and whether GRX810 is the original equipment or your replacement - GRX810 FD chainline is 2.5mm outboard compared to a standard road FD (the crank is outboard by 3.4mm).


What is the diameter of the seat post on Citizen folding bikes? I have searched and cannot find the diameter of the seat post.

I would like to get their Miami or Gotham model, but I know I'll need a seat extension as a 6'2" rider.

Dahon and others make longer seat posts, but I need to know the diameter in order to ensure a fit.

Anyone know the Citizen seat post diameter? Is it 33.9 like the Dahons?

The seat post dimension for Citizen bikes, according to customer support, is 31.8mm.


Correct cable end for Shimano BL-M421 brake lever I have a Specialized mtb that has been changed over from V-brakes to disc brakes (by previous owner). After using it for a while, I've noticed binding in the brakes which I think is due to the way the cable ends attach to the levers. Both L+R levers have the cylindrical cable end sitting in a weird way inside the lever that makes it look like a part is missing.

]2
What is missing here, and/or how can I get the cable end to sit correctly in the lever and not be twisted?
Thanks

Those look standard to me. The saddle you're looking at is designed to pivot as the lever moves to the cable itself isn't bent (because it would fray quickly). The smaller hole on the top is there so you can see what's happening, and on the underside is a larger hole with a slot so that you can get the cable end in and out. How the cable end its once the brakes are set up isn't really important, the system is designed so that the cable/cable end can rotate and your brakes still work.

A wikihow page on changing brake cables has this photo that shows the slot a little more clearly:

I find that sometimes when fitting new cables the saddle will jam on the lever, but once there's tension on the brake cable that will vanish - it's the saddle being out of position that causes the problem.

It's more likely that there's muck around the calipers jamming them up, or the cables need replacing. The brake cable and outer should last at least a year or 5000km (they wear out as well as get old), but it's also possible that especially cheap ones, or ones exposed to salt water, won't last that long. But the bike in those photos looks very clean and new, so it shouldn't be that.

I suggest releasing the cables either from the frame, or if that's not possible, undoing the cable at caliper, and running some chain lube down inside the housing. If you don't know what you're doing this can make your brakes not work, so find some instructions online and follow them if you're not sure. There are a lot of options, and if you can find a set of instructions that match your exact brake it'll be easier.


Replace truvativ crank I have a Shimano UN55 square BB. Within about a month of buying my new bike the Truvativ crank came loose and is essentially too rounded out to salvage. Any suggestions on an alternative crank to go with the existing BB? I would like to avoid replacing the entire crankset if it isn't necessary. Currently running 175mm cranks.

When a crankset comes loose, stop riding immediately and tighten it. Even going a little distance can ruin the crankset and possibly the bottom bracket spindle. It sounds like in your case, the crankset is toast.

We don't have enough information to say if you need a new bottom bracket or not (the Shimano BB-UN55/56 are standard square taper (ISO) bottom brackets and cost about 10-15 dollars), but you need to combine that with a square taper crankset. Alternatively, you can replace the bottom bracket to another standard rather than square taper (e.g. Hollowtech II) and get other cranksets with that standard.


Help! I've rounded off my bolts! I was working on my bike and was about to add some more tension to my SLX clutch mech. While trying to remove the clutch cover I accidentally rounded off the bolts, so I have no way of getting the clutch cover off.

What should I do, can I get the bolts out, can I buy replacement bolts?

Thanks in advance.

If by "rounded" you mean stripped, then you can follow the next steps:

Get a hold on a dremel with a cutting wheel, and Draw a line from side to side(Over the center, like a Diametre line) about the same depth of the hex tool that was supposed to loose the bolt.
If possible, rotate 90 degrees and do the same a point 1
Dip the the part in "Light Coke"(this thing works wonders on siezed bolts, not so much on your health tho) for about two hours. If you can do it overnight, that's ok too.
Optional to (3.), pour some wd-40 on the bolts and threads. If it's has threadlocker then you will need a solvent, like Isopropil alcohol, acetone, or just a plain soldering iron to heat the bolt and soften the thing.
Use a Slot ScrewDriver on the lines you made with your dremmel.

This is by far the safest way to remove stripped bolts.

Other method i've used include to drill a hole on the bolt, and then screw a special tool with counterclock thread to unscrew the bolt out of place, while you screw in the tool. Also you could just drill the bolt out, but you might get to damage the threads on your dereaullier.

The last method, only works on a couple of situations where the thread are not seized, is to take the head of the bolt out. This will take tre preasure off the thread and you can fiddle with it until unscrewd. Did this on a KTM Duke 390.

Cheers


Building a 36er bike I'm casually researching building a 36er bike, preferably mountainbike style. I'm looking for the experience of others on this. I would like to own it more for curiosity sake than any other, but would still like it to ride reasonably well and not be ridiculously heavy.

Are there any frame builders in the US who can put together a decent alloy frame and fork to get me started on this project? Any experiences from others who have tried or succeeded in doing this?

There was an article in the CTC magazine recently about a guy who'd built one. Their website has a FAQ which might be of interest.

Details include:

Tyres/tubes from unicycles
Needed very large disk rotors to make it stop 203mm.
Claimed to fit people of 5ft 3in to 6ft 5in (yes, I was surprised).

Also, I've spotted an example here which looks a lot like the picture in the magazine.


How do I increase braking power and "touchiness" of Sram Guide RS Brakes? I've got some Sram Guide RS disk brakes and they're very weak and not touchy at all. I prefer touchy brakes. I know the Guide RSC has the tool free contact adjustment to make them touchier. I have heard the RS can be changed with a tool but can't figure out how. Does anyone know?

Are they new brakes that you installed or you've had them for a bit and this is a new development? It sounds like they need to be properly bled, with that much lever pull your not getting the pressure that you should be. There could be a leak in the system or if you bled them yourself may not have got all of the air out.

I own the RSC's and their awesome, I have also heard very good things about the RS as well so you should be having no problem with them from a braking standpoint.

Although the "touchiness" you seek may have some to do with the brand. I much prefer Sram over Shimano but many do not. Shimano has what some refer to as an on/off feel meaning they either bite or don't. Sram has a much better modulation where the brakes ease into the slow down rather than just locking up the wheel.

Also if the pads were contaminated or not properly bedded then it could be the issue but it sounds like you have air in the lines still. Guides are typically pretty easy to bleed compared to some others.


What tire should I put on my road/commuter bike to prepare for a New York winter? I have a road/commuter bike (Specialized Tricross) I use for commuting daily in New York City.  The roads here can be quite harsh, with everything from leaves and branches to glass and potholes.  The roads here gave me plenty of flats on the stock tires, so I replaced them with 28mm Continental Ultra Gators, and haven't had a flat since.  I already have full coverage fenders with mudflaps on, and they've been very helpful on rainy days.  Now winter is approaching and I'm wondering whether to swap out the tires.

I rode in winter here last year, so I'm familiar with the challenges, but I'm not perfectly satisfied with how my current setup performed.

The issues are:

About 60% of the time it's really no different from the rest of the year, just colder.  A significantly heavier or knobbier tire would slow me down on these days.
About 10% of the time you get flurries or light snow that doesn't stick, and the smooth tread on my tires makes turning a bit dicey, but otherwise manageable.
About 10% of the time there is some fresh snow on the ground, and turning can be very challenging, but going straight is fine.
About 10-15% of the time there is older snow on the ground, mixed with patches of ice.  I am able to proceed in a straight line at a slow and steady pace, about 10-12 MPH, occasionally getting off for steep hills and sharp turns.
5% of the time conditions are such that it is completely unrideable, and I end up walking the bike home if I happen to have ridden it to work in the morning.  I will often avoid riding in the 10-15% conditions mentioned above to avoid being faced with these conditions later in the day.

Do I need a completely new bike for the winter (or should I just take transit 20% of the time), or will putting on different tires help?  Another possibility would be to buy a new front wheel with a very wide tire, and switch out wheels on bad weather days.  Has anybody tried this out?  Would I be OK with a smooth tread on the back?

You say you've got a small apartment that can't accommodate two bikes, but how about two sets of wheels?  The only thing that can deal with ice is studded tires, so for those 20% of the days that include ice, you need studded tires.  Your Tricross should be able to accommodate such wheels, so it would simply be a matter of changing wheels rather than buying a whole new bike or using transit.

As for those days it seems okay in the morning but turns into an icy day in the evening, all I can suggest is paying careful attention to the weather guessers and guessing conservatively.


Spokes are too long for wheel build. What did I do wrong? Tonight, I began the process of building a new wheel.

I purchased an Industry Nine Hydra Hub (MTN - 32 hole - Classic Rear Hub - ISO 6 Bolt - 12x148 HG)

Here are the calculations posted on their website:

I am pairing it with the Spank 350 29" Rim. Here are the calculations for the rim:

As for nipples, I purchased these:

I checked on several different spoke calculators. This is the spoke length calculation I got:

Drive Side Spoke Length: 290.7mm

Non Drive Side Spoke Length: 292.4mm

Drive Side Spoke Length: 290.7mm

So, I bought 290mm spokes and 292mm spokes.

But, halfway through building the wheel, I noticed the spokes are way too long... like to the point my wheel build is definitely not going to work with these spokes. I have 16 spokes on the wheel and all of them are sticking out of the outer nipple holes...

My Question:

What did I do wrong in my calculations? What is the correct spoke length?

I have this bad feeling that it has something to do with Spank's "ERD++" calculation, but I don't understand their wording:

  ERD and “++” – It’s important to note that the “++” callout in Spank
  published ERD measurements for all our rims, refers to the height of
  the nipples you are using in your wheel build. You must add 2X nipple
  head height (specific to the nipples you have chosen), to the ERD when
  calculating spoke lengths. In the past ERD was usually communicated as
  a calculation including a standard nipple head height, (Inner Diameter
  of the Rim + 2x Spoke Bed Wall thickness + 2x Nipple Head Height =
  ERD). However, in recent years many new standards of nipples have been
  introduced, and nipple head heights vary. For example a standard
  external nipple has a 2mm head, while a DSN type nipple has a 4mm
  head. For this reason, Spank communicates ERD without including nipple
  head height, so the user can add the exact height of the nipples they
  have chosen for their build, (Inner Diameter of the Rim + 2X Spoke Bed
  Wall Thickness = ERD ++).
  https://spank-ind.com/apps/help-center#!faq-article-1

... Does that mean I'm supposed to add more to the ERD? I just used 602mm. If I had to add to the ERD, the spokes would be even longer, so I don't get it.

The spoke lengths were correct, I just laced the wheel wrong. I fix the lacing issues and now the wheel is looking good.

If you ever suspect that your spoke lengths are off, just make sure you laced the wheel correctly first.


Right vs Left Crank Power Transfer Efficiency The drive-side crank of a bicycle must be more efficient than the non-drive side, right?

Not only does the power not have to go through the BB, but the drive side is usually also attached to the chainring out closer to the end, especially on high-end cranks like this one:

Is there any data on the size of the difference in efficiency? I'm not looking for data on this specific crankset, anything general is fine.

There will be windup (flex in the crank under force).  Both the drive side (spiders and chain ring) and the non-drive side (shaft, spiders and chain ring) will experience windup during power transfer.  The amount of wind up is however very small (and depends on the magnitude of the force applied), but will be slightly higher for the non-drive side as more components are involved.

That said, once the small amount of windup has occurred (at the start of the power stroke), both sides will transfer force with equal efficiency for the rest of the pedal stroke.  Because the windup is so small, overall efficiency between sides will be essential  identical.

As an aside frame flex will be a much bigger component, convince your self by locking your brakes and apply force to either crank and see what flexes. I find I have better power transfer with the right amount of frame flex as it allows me to get into a rhythm  that I can best describe as like riding a wave.  Some term this planing.  What ever you call it, a bike and components that are too stiff will feel "dead" for lack of better words.


Which waterproof overshoes would you recommend for use with clipless pedal shoes? Last Winter I bought some waterproof overshoes on the internet to keep my feet dry on the daily commute. Unfortunately these overshoes fastened with a velcro strap which fastened underneath the shoe obscuring the cleats in both my road shoes (SPD-SL) and mountain bike shoes (SPD). I managed to get by tucking the velcro straps inside the overshoes and wearing them loose, but they have never really stayed secure that way.

Can anyone recommend some waterproof overshoes that:

Keep your feet dry
Fit snugly and don't come undone on a ride or catch on the bike
Have fittings which don't obscure cleats and work well with clipless pedals
Are reasonably priced

For serious winter riding (I rode for 12 years all year round in Toronto, Canada, and while we had reasonable weather, it did get wet, cold, and icky a lot) I gave up on clipless, and just used platforms with a pair of hunting boots!  Canadian Tire sold -40C and -70C versions.  (I rode in -35C in the -70C pair, and I gotta say, my toes were quite comfy!)

Tuck a pair of ski pants or waterproof pants over the tops, and that was the driest I ever attained in bad weather.

They bend surprisingly well so pedaling is not the issue, and you have good stability in bad weather.  You know, if you are sliding, and put down both feet with those big boots, you might still slide a distance, but you can control it better.

I never tried anything like you suggest, as based on other waterproof clothes, once it gets wet enough, nothing is water proof.  Everything has holes, seals, zippers, seams, etc...  They help, no argument, but not all the way.


Alternative uses for an aluminum MTB frame Any alternative use for old mountain bike tyres and inner tube?

So my frame has a large crack near the headtube and I am replacing it. Could I use the frame in any other way? E.g.

give it away for recycling, get a few beers with the money
make vases from the tubes
make shot glasses from the tubes (e.g. with wooden bottoms)
beat people with it (!?!? one friend proposed this)

Anything more sensible? Maybe I could make some tool or stand out of the material?

Use as a dedicated truing stand.  While not adjustable, the fork could be used for front wheels, back for rear wheels.


Can dropout break due to a faulty cassette or a bad installation? Backstory: I currently have a BH Ultralight RC road bike that I use to ride to work. About 6 weeks ago I took it to the bike shop because the pedal was slipping over the cassette when I took off, so they changed the rear cassette and the chain, and they did a few other things. It cost $220, but The bike was running very smoothly.
Then about a week the dropout (that's what they called it) literally snapped and the rear derailleur got stuck in the rim. I took it to the shop again, they straightened the "transmission" (what they said), they also straightened and reused the chain, they changed the spoke and they installed a dropout. I picked it up and took it home.
The issue is that I rode it yesterday for the first and the ride is terrible: the pedal's slipping again, the chain is always scraping something regardless of the shift, and it's making all kinds of noises. It's just terrible.
Since they said that the cassette and the chain was damaged from the dropout break, I'm almost sure that they'll want to change the rear cassette and the chain once again. My concern is that the dropout has never snapped like it did before (I didn't even know that existed), and I'm thinking that it broke because they didn't install something right the first time I took it.
Question: is it possible that the dropout broke because something wasn't done correctly when the new cassette was installed?

It is possible that the rear derailleur low limit screw was misadjusted such that holding the shifter down allowed the RD to get snagged by a spoke. That is a fairly common cause of what happened.
Another possibility, also common, is the hanger (what you are calling the dropout) got bent inward for whatever reason, usually uncareful handling of the bike or crashing, after it left the shop, and the RD was able to get snagged that way
Unless something like a stick or vertebrate got caught in the wheel while riding and was able to reach over and snag the derailleur that way, it's likely one of those two scenarios. If you knew what click the shifter was on when it happened, that would be a clue.
It would be weird if the derailleur was unscathed enough to not need replacing completely. They're unobtainable for shops in a lot of cases right now, so that could be a factor that led to some kind of decision to de-mangle rather than replace it, which is idiotic in normal times but can now legitimately constitute good customer service. If this is what's happened, it could be causing the current bad performance and noises, as they usually wind up too misaligned and sloppy to work great. It's also of course possible they just did a bad job.


How to properly remove bearings from shouldered-axle track hub I am trying to learn the right way to remove bearings from a track hub. The bearings are cartridge bearings pressed into the hub. The axle has a ridge that prevents it from being removed while both bearings are in place.

I know there are bearing pullers like this one from Enduro:

But these require that the axle already be removed.

So what is the proper way to remove these bearings? I know that I can just tap the axle out with a rubber mallet and force one of the bearings out, but I think this would damage the bearing.

With a trapped axle like that you use a hammer, ideally a soft face one or I use a bit of wood as a pad. Hold the block against the axle, tap the block with a hammer. Holding the wheel in your hand rather than blocking it against a solid surface also reduces the impact. You will still probably damage the bearings, so preferably don't do this until you have the replacements.

Arts Cyclery have a video tutorial and the hammer appears about 70 seconds in.

In my experience this is actually easier than the removable axles, because even a decent bearing puller often doesn't work, or work any better than just using a hammer and punch. The small hole in a bike wheel bearing (10mm) is often too small for the puller.

Press the new bearings in carefully making sure you press the outer races not the inner ones.


Spoke tension is way off but wheel is true, How do I fix this After truing my front wheel, it seems that it is laterally true.  However, the spoke tension seem very uneven, with a few spokes that are very taut next to other spokes which are more loose.  If it was a small difference, I wouldn't be too concern, but it seems a bit too big of a difference in tension that has me worried.

I have access to a tension meter and a pro-grade truing stand.

How should I fix this?

Should I loosen all the spokes and start from scratch or fine tune the existing setup?

For reference, I used to work for Velomax Wheels, and Easton Wheels.

You may want to back all of the spokes off an equal amount, say 5 or 10 turns.  This will give you a little bit of room for adjustment, without having to completely detention the entire wheel.

There is a book called "the Bicycle Wheel", by Jobst Brandt, that does a great job of walking you through the process of truing.

Another way to tell if the spokes are of equal tension is to pluck them like guitar strings.  Since they are all of the same length and same thickness, equal tone means equal tension.  (We used to attach an electronic "pick up" to our truing stands, and wear headphones so we could better hear the differences when we plucked the spokes.  This shouldn't be necessary say, in your garage where there is a lot less ambient noise.)

A couple tips for truing (though you may know these already):
- Be sure to back off any adjustment that you make on a singular nipple. This will eliminate any possible spoke 'wind-up" caused by the twisting of the nipple.  (example - if you want to make a 1/4 turn adjustment, turn the nipple a 1/2 turn and then back off 1/4.)
- Be sure to give adjacent spokes a soft squeeze to help the spokes and nipples settle.
- check for cracked nipples and cracks at or near holes in rims.

Once it is true, then you can bring all spokes back up to tension (the 5 or 10 turns that you originally made.)

Truing stands are very helpful in holding the wheel in the right position to make your adjustments.  (Rather than trying to do it in your hands or in the bicycle frame/fork.)  they also typically have a measurement pin or finger that helps show where (and to what degree) the wheel is out of true.

Tensiometers are okay devices.  Here are a couple of their downfalls: 1-no two are the same and they come out of calibration quite easily. 2-several factors, such as how you hold the tensio on the spoke and where you place the tensio on the spoke, influence the gauge reading.

Hope this helps.


Replacement brake pads for Tektro HD-R210 What model pads would be a replacement for Tektro HD-R210 brakes?

I haven't seen the model mentioned in Tektro's documentation
https://www.tektro.com/upload/Product/F_20170613131999DtkdK8.PDF

The bike is a 2019 Giant Fastroad SL-1
https://www.giant-bicycles.com/au/fastroad-sl-1-2019

Around the front calliper the only marking is F140 FM1.1

I don't see any marking on the rotor for resin only.

The front brakes have been a bit noisy & bumpy under medium braking, and the pads look thinner at the side closer to the rear of the bicycle. It looks a bit like there's wear on the outer of the rotor arms. I guess this is related to pad wear?

I'll swap the left and right pads over until I get a new set, hopefully that will put a bit more pad where it's needed.

It's the most common Shimano-originated pad form factor type, which doesn't have any one agreed-upon name but is often listed as "M525/515", "Deore Mechanical", "M475/425" and others. The "A10.11" is the Tektro model for the pads you have, which are what they call a metallic ceramic compound. You could just keep it simple and get more of those, but all the aftermarket pad manufacturers plus Shimano have offerings for this type in both metallic and organic/resin. There are a lot of questions here about organic vs metallic. Shimano B01S is an extremely cheap but good quality resin pad that would work.

The noise/chatter you mentioned is most often related to inadequate bedding. Metallic pads make it worse and will give some noise even when things are going right.


Has anyone had success mixing and matching cassette sprockets for custom ratios? I have a 9 speed rear cassette that I am looking to replace some or all of. I would love to have a 9 speed cassette with a 10 tooth or even 9 tooth top gear, but the combination doesn't seem to be available with existing cassettes, so I am contemplating a mix and match affair.

I know each sprocket is indexed and has particular profiles to smooth the down and upshifts depending where around the cassette the shift happens, so this might make the idea a bit crap.

Alternately can someone point to an existing 9 speed cassette that is 10-28 or 9-28?

As far as I’m aware there are no 10 teeth sprockets for normal Shimano hyperglide freehub bodies because the freehub diameter is just too large. That’s why SRAM created the XD Driver standard and Shimano created the Micro Spline standard.

Can’t you install a larger chainring and use a 11–30 cassette?


Relationship between given width of a tire and actual height I've spent some time digging around and can't quite find a satisfactory answer here. I have an older (80's) road frame that currently has 622x23 tires. I would like to upgrade to 28mm or even 32mm tires. Generally the issue with larger tires is clearance between the brake calipers. In my case this is not the issue. The calipers themselves are plenty wide to accommodate much larger tires. The problem at hand is the clearance between the top of the tire and the cross beam between the seat stays where the brakes are mounted. It's quite small (3-5) mm. So... Is the diameter of a tire affected in three dimensions, or will a wider tire (28mm vs 23mm) also be "taller" aka vertically higher from the rim. I've seen a few comparisons and tire reviews that imply width and height are separate, but that seems logically impossible based on the inner tube expanding equally in all directions. Any clarification on this would be wonderfully appreciated. Thanks and smooth roads ahead ; )

In bicycle tires the height and width are directly related. This is because unlike unlike car and motorcycle tires, the cords that hold the tire together are aligned diagonal and the resulting fabric stretches to round shape when inflated. The tube does not have anything to do with it, because it expands to fill all available space. If you have a piece of non stretchy fabric like a flannel shirt at hand, you can try stretching different directions to see how it works.

Tires that have thick tread are taller than fully round tube shape would be, because tread is outside of the fabric.


How to make the most out of daily commute? I have heard that bicycling is a great form of cardio exercise. I bike to and from work everyday and the whole way everything is flat. I am not sure what the best way is to make the most out of the exercise.

Should I pedal as hard as I can the whole time?

Is this a good enough alternative to jogging?

Interval Training.

It's a type of workout where you alternate bursts of energy with periods of recovery. There are many variations of interval training. If you want cycling specific intervals, you could try "The Time Crunched Cyclist" by Chris Charmichael. The book is primarily about training for Centuries or racing, but if you follow the methods, you'll get into great condition. Interval training is an excellent cardo workout and a great alternative to jogging.

One popular method of interval training is the "Tabata" method. This uses 20 seconds of ultra-intense exercise (at an intensity of about 170% of VO2max or 90 - 95% of your max heart rate) followed by 10 seconds of rest, repeated continuously for 4 minutes (8 cycles). Typically, this is done 3 or 4 days a week and not on consecutive days.


Effect of reducing tire pressure for riding on snow All other factors being the same (normal carved tires, 28x1.40, paved road with 5-10 cm snow), does reducing the tires pressure provide any improvement for cycling onto snow?

My idea is that lowering the pressure increases the contact area and thus the grip.

Lower pressure for a larger contact patch to increase traction is common.  Cyclocross riders (for one) use low pressure.

Weigh that against pinch flats.  As you lower the pressure you increase chance of pinch flats.  In snow the pot holes and bumps are partially hidden.

Tread type and depth will also affect snow traction.


Anyone have Open Bars or similar on a Surly Cross Check or Straggler? I read around the Internet that many people use a Cross-Check/Straggler as a basis for a relaxed-ish commuter bike. But I'm told by my LBS that running Open Bars or similar on one of those frames is at best missing the point and at worst will make the bike handle poorly.

Can anyone confirm or deny this from personal experience?

I spent some time on a century ride with a guy who had porteur bars on his cross check.  They certainly did not seem to slow him down or make him uncomfortable.  The Cross Check (full disclosure I do not have one) is the Swiss Army Knife of bikes.  I say go for it... ride it for a season and if it is not your thing re-configure that ultimately configurable rig.


Can't change M7000 front shifter from 2x into 3x I bought exactly this set of shifters, latest SLX model.

I had similar SLX shifters, just the older ones, where the front one had a little button so it was easy to change from 2x to 3x.

Now this new one has nothing on the bottom or at the top, I do not see any kind of hint on the internet, how the hell can I change this shifter to 3x?

Here is all the info Shimano provides, but there is NOT a SINGLE WORD about switching into 3x mode.

This is a hilariously minor problem, which still cause a pretty big trouble to me.

According to Shimano's current documentation there are separate 2x and 3x specific shifters, not a single model that can be configured either way. The web-site you linked to appears to be misleading on this point as it implies the shifters can work for both 2x and 3x.

Find the exact product codes of what you received and check against the Shimano page. If you have the 2x specific shifters, return them.