Is it better to get an entry-level carbon bike or a similarly priced aluminum bike? I am going to buy my first proper road bike, and I have been comparing entry-level carbon frames with top-level aluminum frames in the same series (Giant Defy). What are the benefits of carbon vs. aluminum frames? Is it better to get an aluminum bike with higher-end components or a similarly priced carbon bike with lower-end components?

Essentially this is about low end carbon versus high end alloy. Carbon is typically lighter and less harsh (more vibration absorption) than alloy, but is not as robust. I doubt that the alloy is much heavier. I think it will come down to the difference in component quality and your budget.

Personally for a training bike I would probably go for the alloy, but that is driven by my financial situation. If the bikes are of similar price and the components are of the same quality, I would consider the carbon.  However I would not trade component quality for a carbon frame.

Edit : Seven years after the answer was give.
Many of the tecniques learn laying up carboon, and with advances in hydroforming alloy, have lead to allow alloy frames that are significantly cheaper to fabricate yet nearly as light (if not lighter) than low ebd carbon frames, while having teh characteristics of stiffness and complance where wanted. You can no longer discuss 'Carbon' and 'Non-Carbon' frames as most major manufacturers have 2, 3 or more variations of carbon from 'cheap and cheerful' to 'insanely light and expensive'. The cost saving in Alloy frames put into better compenets leads to a better bike for the same build cost. As carbon is consdidered more desireable by many, it fetches a higher price for the bike.

TD;DNR when buying a bike, look at the whole bike, not just the frame.

Quality-wise bikes are a lot like chains. The total quality of a bike (where with quality I mean stuff like durability, smoothness, ease of use, ease of maintenance, etc.) is very dependent on the weakest link.

An expensive frame with cheap components makes for a worse bike than a mid-range frame with mid-range components. So given the choice I'd go for the (relatively) cheaper frame with the (relatively) more expensive components, all dependend on what I actually wanted to spend on the bike.

There are "ride quality" differences between carbon and aluminium and steel. Carbon is usually less stiff, so the ride is a bit more comfortable. Steel has the same properties as carbon and is more durable, aliminium is usually a lot stiffer and hence the ride is harsher. For that reason you get aluminium frames with carbon fork and stays. The main disadvantage of steel is of course weight, but you have to look at this critically. The 0.5-1 kg weight reduction you get by going from a really good and durable steel to a carbon frame disappears in the 15-20 kg of fat you are lugging around anyway, and unless you plan to go ride a lot of serious races you will never notcie the small gain of the lighter frame.

Where I'm going with this: In the standard bikes you buy the frame is often of higher quality (and price) compared to the other components. You can get a better bike for less money if you pay attention to this when buying your bike. Spending some time talking this over with you friendly LBS owner will help here.


Which tires are best for on and off road use? My tires are worn out so I want to change them.

When I am trying to change them, I want them to be to the best fit for the conditions I cycle in. I cycle about 30 km a day on roads ranging from smooth pitched roads to very rough roads consisting of pits and stones in the most haphazard way.

Please suggest a type of tire that would be best for me. There do not need to be considerations for snow, it does not snow where I cycle.

What you are looking for is a hybrid tire with not enough tread to be a nuisance and slow you down on the road, but enough tred so that when you go off road you are not losing traction on gravel and mud.

For example Bontrager makes a hybrid tire that is nice:

Also, go with the hard wall tires whenever you can. they cost a little more, but they are more puncture resistant. So they will cause you less grief on the road.

I think the best option for your neds is Scwalbe Hurricane. Smooth, silent and quick on smooth surfaces and rough off road. But it is not always available (sold out?). Schwalbe Marathon is too smooth.


Clicking while pedaling I recently purchased a 2nd hand bike, and I am facing a clicking noise when I pedal (under slightly higher than normal load). I feel it almost as a pair of clicks in both pedals, and I feel one click when one pedal is ahead and another click when the other one is ahead (1 click when each pedal is at 5'o'clock position and I add weight on it)

What I tried.
1) I noticed this first after changing the pedals, so i changed it back, tightened the pedals multiple times but it persists.
2) I tightened the screws on the cranks/chain rings (spider to chain ring) (they were quite quite loose) but it didnt seem to help (Are both the chain rings held with the same screws? I use the little chainring only)
3) I tightened the 8mm hex holding the crank arms itself. Also didnt seem to help.

2) and 3) Seemed to get loosened after the ride, so I wonder if they are indeed the problem. I have tightened them tighter now, hope to see in the next ride.

I have not done anything with the BB yet.

What else to look at, what can I do/try? Makes my bike feel very cheap :P I want to fix this.

If the click is felt in both pedals the problem is likely to be the bottom bracket bearings.

You should be able to feel bearing stiffness, roughness or 'notchiness' be turning the crank manually. It helps if you can get the chain off the rings to do this so the crank turns freely. Also check for any play of the crank axle in the bearings.

If the crank axle is not turning smoothly in the bearings or there is excessive play you likely need a new cartridge bottom bracket unit. These are not expensive but require special tools to take off the cranks and extract/install a new BB unit.

It's a bit worrying that you are finding loose bolts all over your drive train. You should probably do a complete drive train checkup to make sure there are no other lurking problems.

The cranks bolts are of special concern. If the alloy crank arms come loose on the steel axle taper they can be terminally damaged in short order. The bolts can be removed (the crank will stay on the axle), the bolt and internal thread in the axle should be cleaned and de-greased then the bolts -re-installed with non-permanent thread locker (e.g., blue Loctite) and torqued to proper specification. (This will of course all get done if you replace your bottom bracket cartridge.)

I had the same increasing clicking when pedaling slightly harder and changed the bearings,  changed the chainring change the chain, changed everything!! Still clicking and worse after the repair....i started to panic about the carbon frame on my top specs Trek mtb until....i read your post...jumped on the torque wrench and waked 200kgm at it, went on a test ride ...et voilà!! Problem solved .I can't tell you how grateful I am for your post,  you saved my sanity and my money! All the best Etienne


Will electric heaters degrade bicycle tires? Is it safe to store bicycle tires near electric heaters? I'm wondering if the heat will degrade the rubber somehow.

More specifically, I'd like to store my bike near the electric baseboard heaters in our apartment.

It depends on a lot of hows including (but not limited to) close, hot, long, and manufactured.

Most well manufactured tires that are mounted and aired up will mostly suffer from air loss.  As the tire and tube heats up, the pressure rises and the tendency to leak a bit of pressure over time will be exaggerated.  Tubeless setups utilizing juice may see that juice evaporate/dissipate quicker.  Tire/tube setups that were recently inflated to max pressures in much colder environments may actually blow out (happened one time when I left a wheel in front of a sunny window).

If you are talking about storing your bike along side a baseboard heater or similar, you are probably going to be ok short of actually leaning the tires directly against the heat source.

Electric baseboard heaters are entirely resistive heat, so there should be no problem assuming the temperature isn't extreme.

What becomes a problem is if you store the wheels near a DC electric motor that uses brushes. These produce a small amount of ozone, which contributes to the premature destruction of tire rubber.   Most AC motors are brushless, so are fine.

However, you should know that some air purifiers work by producing ozone. In addition, some office equipment such as older photocopiers also have DC motors that produce a lot of ozone. These have mostly been phased out because of health concerns but are responsible for the characteristic smell of copy machines.


What should I do about a tensioned/trued wheel that lost significant spoke tension after first use? My front and rear wheels needed truing, so I picked up tools to do it.  Rims are DT Swiss R460: 20 spokes front, 24 back.  Max spoke tension is 1200N.
I got my front wheel to a left-side tension range of 685-889N and a right-side tension range of 685-938N, and I got my rear wheel to a left-side tension range of 540-720N and a right-side tension range of 758-991N.  Numbers are without tire or tube and after de-stressing both sides of each wheel.  I adjusted each spoke using tighten-then-back-off spoke wrench technique.  I didn't use spoke prep -- figuring it wasn't strictly necessary for an existing wheel if I was attentive and executed tighten-then-back-off correctly.
I put tires and tubes on the wheels and reinstalled them, then did 13mi Sunday.  The rear wheel felt maybe more "taut" than normal (from fresh reinflation to max 120psi?), but otherwise things went fine.
It's now Tuesday, and I figured it'd be a good idea to recheck tensions after a ride and some time.  Didn't remove the tires, just popped the bike in a stand and ran the TM-1 over a few spokes.  The tensions were much lower, 14-16 on a TM-1 versus 17-22 before for a few random left-side spokes on each wheel.  (Maybe "taut" is not actually what I was feeling in the rear wheel.)  That decrease isn't normal -- is it?
Should I just tighten all the spokes to get them to a more desirable tension range again?  Is it normal for tension to decrease so much from putting an inflated tire on a wheel?  (This answer suggests no.)  Should I remove (or at least deflate) the tires before doing so, and if so should I tension beyond 1200N assuming some loosening when a tire is added again?  (This answer again suggests no.)  Or is my no-spoke-prep tactic coming back to bite me, prior tensioning would likely have been fine if I'd used some, and I should apply some to every spoke and then tension things up?

Yes, it’s normal for spoke tension to decrease when the tire is inflated.
First of all I’d use much more tension and try to get it more even. Currently you have about 30% difference between slackest and tautest spoke, which is a lot (I’d aim for ~10%, but I’m a perfectionist in that regard).
540N on the slackest rear spoke before you’ve even inflated the tire is very little. I’d get the drive side spokes to slightly over the allowed 1200N and hope that the non-drive side ends up around 700N.
I’d also aim for 900N on the front wheel.
All tensions assuming zero tire pressure.
Considering the low spoke count and the high tire pressure you are using you could go for even higher (initial) spoke tension.
I’ve had good experience with using grease on the spoke nipples (on contact surfaces and thread). Makes truing much easier, avoids wear from truing and also avoids deforming the spokes or nipples from all the tension force.

My front and rear wheels needed truing, so I picked up tools to do it. Rims are DT Swiss R460: 20 spokes front, 24 back. Max spoke tension is 1200N.

Ouch!
1200N is a reasonable spoke tension for a 36-spoke wheel. To keep 20 spoke wheel in tension, it would need 2160 N tension, and to keep 24 spoke wheel in tension, it would need 1800 N tension.

That decrease isn't normal -- is it?

It's exactly what you would expect for a low spoke count wheel. The wheel stands on the few bottommost spokes. The fewer spokes there are, the fewer spokes the wheel stands on. A severe bump in the road and the momentary load can be 200-300 kg (2000 - 3000 N). A 20-spoke or 24-spoke wheel cannot withstand that load, so the bottommost spoke is slack and the nipple on the threads is free to turn due to vibration.
As a bad fix (not recommended), you could try some thread glue in the nipple threads. They will prevent the nipples turning freely. This is both a good thing (bump + vibration does not loosen the spokes), and a bad thing (your wheel truing just became harder).
As an ultimate fix, throw away these poor rims that were clearly designed by an incompetent engineer (who would design a rim that has both fewer than 36 spokes and maximum tension reasonable for 36 spokes?), and try to find a rim:

That has 20 spokes and 2160 N maximum allowed tension
That has 24 spokes and 1800 N maximum allowed tension
That has 36 spokes and 1200 N maximum allowed tension

My recommendation is the last choice. Experience has shown that 36 spoke wheel is a reasonable compromise between low and high spoke counts and very durable.


What is a good iPhone app for bikers? There are tons that are out there for recording routes, and such.  There's also the physical mounting.  Is the iPhone actually good/useful for bikers?

Cyclemeter is my favorite ride tracker.  If you are a bike commuter, you will appreciate seeing your splits and daily times.

Endomondo is also a nice app, and runs on a variety of other smartphones.  It's free, but more web-based, whereas cyclemeter is more phone-only.

I add another app to this question : CoachMyRide

CoachMyRide is an iOS (iPhone and iPhone Touch) application dedicated to improve your training.


Does Bike or Rider Weight / Groupset affect cruising speed on the flat I posted this video on Facebook:

and someone commented that my power readings were a bit "optimistic" I asked why and he basically thought that if I'm getting 600W I should be doing a lot more than 30 MPH. He says he can cruise at 30 MPH at only 250W!

In the end he seemed satisfied that the difference is that he weighs 74KG, I am a bit over 100KG.

On another video someone commented that he would fly on a carbon bike with a nice groupset.

It seems to me that weight of bike / rider and groupset is going to make very little difference cruising on a flat with no gear shifts.

Am I suddenly going to end up cruising at 40MPH at 600W when I loose 10KG?

The short answer to your question is, "yes, weight does affect cruising speed on the flat, but not by much."

The longer answer to your question is a special case of one of the answers given to this bicycles.stackexchange question: "How can one estimate drag for a bicycle?" There you can find the equation for power given speed, disaggregated into the components for aerodynamic drag, rolling resistance, acceleration, and climbing (or descending). In your case, you are only interested in the components of drag that are affected by a change in mass.

You have asked about "on the flat" so we can ignore the climbing or descending component.

You have asked about "cruising speed" so we can ignore the acceleration component.

If you look at the drag equation, mass does not enter into the aerodynamic component.

The only component of drag, then, that is affected by mass is the rolling resistance component. Rolling drag force is Crr * m * g where Crr is the coefficient of rolling resistance, m is the total mass, and g is the gravitational "constant", probably about 9.8 m/sec^2 in your location. For "normal" road tires on a standard surface, the Crr will typically be in the range of .004 to .007; heavy tires on rough roads will tend toward the upper part of that range, racing tires on a good surface will tend toward the bottom part of that range. In this case, let's say the Crr of your tires on that road is right in the middle of that range at .0055, and that the all-inclusive weight of you and your bicycle and all of your equipment is a total of 110 kg. Then the rolling drag will be .0055 * 110 * 9.8 = 5.9 Newtons. For each kg that you decrease the total all-inclusive mass, the rolling drag will decrease by .0055 * 1 * 9.8 = .0539 Newtons.

Power is force * speed, so for constant power output the change in speed due to decreased mass will simply be power/change in force.

So, suppose your "cruising" power was 300 watts, your total mass was 110 kg, your CdA was 0.3 m^2 (which is low for a commuter bike setup), and the Crr was .005. We can then calculate your speed as around 10.9 m/s (or 39.2 km/h). If you were to decrease your mass by 10kg, roughly 10% of your total mass, your speed would increase by about 1%, to 11.0 m/s, or 39.6 km/h.

The more you weigh, the more power required to get to, and maintain a certain speed.. but at the same time, generally, the more power you can produce.  On the flat you're mostly working against air resistance, a larger framed rider (less aerodynamic) will need more power to overcome the resistance than a smaller rider.  Generally aerodynamics of rider & weight of rider will have a strong correlation.

30mph is not at all slow, if you were able to maintain that for 20 km you'd actually post reasonably competitive times in a pro TT!

A better groupset might save weight (although that's more important with climbing & accelerating), it might also give you a better selection of gears & better power transfer.  A carbon bike might be more aerodynamic.


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.

This is the most common way, lowering the pressure ob the tires when in the winter. The idea come from a physical fact that when the tires have lower air, their contact area with grount level will be expanded, in other wird the height of car will be near to the ground.


Adjusting rear derailleur - shifts to lower gear, but not to higher Well, it will shift to a higher gear, but it takes two clicks of the shifter and it skips over a gear when it does shift. With one click the chain hangs on the current gear by the slimmest if threads. It's quite amazing really.

This is a new derailleur, a Shimano RD-M410 Alivio SGS, on a cog set that predates index shifting. Could that be the problem?

I have tried adjusting the barrel adjuster, but that doesn't seem to have any effect (on this problem).

Also, I put bar-end shifters on the bike, so the cable seems a bit short.

Edit

The cog set has 7 gears, but the shifter has 8.

Thanks.

Perhaps your shifter cable can't slide smoothly. Shift to the tallest gear (smallest cog). Pop the shifter housing out of the brazed-on stops. Slide the housing back and forth and look for stiffness. Put some lube in the housing and slide it back and forth to distribute it.

Perhaps your derailleur hanger is bent. A bike shop will have a tool to easily check its alignment.

If either of these is a factor, then you will never be able to adjust your shifting properly.

I am not above easy points!!!

:)

sheldonbrown.com/derailer-adjustment.html


Bike pedals not moving for upright position I need the help with my bike. When starting a bike (stopped position), I cannot move my pedals to the upright (power) position before starting. When I stopped in the traffic light, I need to move my bike to return my pedal to the upright position. I wanted to ask if it is normal for some bikes or there is a problem with the bike.

I suppose it is not fixie. Correct me if I am wrong. Is it possible to get it changed?

Since you don't mention that you don't have a fixie where this wouldn't be possible anyway, if your bike's rear brake has a back-pedalling aka coaster brake, turning the crank backwards is indeed not possible. It is system-inherent.

More information about the above posts are needed, please.
Looks like a coaster brake to me in the picture


Standing to pedal is extremely tiring - should it be this difficult? I've gotten back into riding fairly recently. I used to ride a bicycle a lot when I was younger - the single-speed, steel-frame deal with coaster brakes. I'm now riding a Fuji hybrid.

When I was younger, standing to pedal was the thing to do. However, now when I do it, I can't really sustain it for more than four seconds, literally; my quads ache and I feel as though I have absolutely no endurance for this. This happens not only on hills, but on flat as well.

Sitting to pedal has been alright for the most part. I'm able to climb hills in low gear (even though I'm really not good at it yet) and I can pedal well on flat ground. Standing is just a different story, as it takes it out of me so incredibly quickly that it's an almost useless technique.

Am I doing something wrong? Might I need to adjust my handlebars to be higher or something? (My saddle is at a correct height, but perhaps when I stand, I'm having to lean too far forward to keep my hands on the bars?) Or is this common and it's something I'll just need to get over with practice? Don't get me wrong - I know that these things do come with time - but it doesn't seem to make sense that I get tired standing to pedal even on flat ground...

Thank you.

Standing up on a bike, especially when you lack fitness, is a good way to go "anaerobic." Put simply, that means your body is working so hard, it can't get enough oxygen. You can only do that for a short amount of time, which for most people is in the range of 10-30 seconds. Then the lactic acid build up in your muscles becomes too painful and you are forced to ease up.

The solution is simple. You need more strength and fitness. If you like to ride fast and/or climb hills, you can't avoid the anaerobic zone completely, but you can move it a little farther away by getting good fitness. Keep riding, and keep riding hills.

standing while pedaling should not necessarily be harder than sitting - it depends on how you're doing it. if you're in a hard gear, and/or cycling up hill, it may in fact be easier to stand while pedaling so that you can exert more downward pressure on the pedals.


MInor (I think) dent in top of Orbea Alma top tube - frame ok or no? UPDATE: My lbs mech / owner (same guy) looked at it this AM, says it is good to go, 'ride the hell out of it', he 100% backs it up. And FWIW re: the specifics of this frame and why it's purely cosmetic, he tells me that the top of the top tube, in that area, isn't the load-bearing part (the sides of the top tube are where the material's beefed up and takes the load). Which makes logical sense to me, for this frame anyway (I wouldn't speculate about other frames, I think frame-specific knowledge is key here). The sides of the top tube show zero signs of the impact, no bending / warping, etc etc. Good to go.
Anyway, thanks to all for the input, much appreciated! Ride on...
-cw
2015 Orbea Alma alum frame top tube, looking front left to back right. This pic gives the best angle on the contour - the sides of the top tube feel unaffected by this dent, and you can see from the black center line bisecting the tube that the majority of dent is on the left from the left shifter pod, so what you see here is the worst of it I think. Any general impressions regarding whether I have killed this frame or not would be much appreciated, thank you -

Just off the picture I'd say it's fine. Aluminum is more durable than many people think (you know they build airplanes out of the stuff?!) That said, I would carefully look at the areas where the tubes are welded together. Use a bright light and look for any small, hairline cracks in the paint. Most of the aluminum bikes I've seen fail usually snap at the welds (outside of horrible crashes of course)

Don't ride that. Aluminum will randomly snap at the best of times, and a fold-looking bend like yours only makes it worse.


List of essential tools to maintain an Ortler Mainau bicycle We have three Ortler Mainau bicycles in our family that I would like to maintain. We don't have a garage but only a smallish cellar, and I would like to work there (e.g. I cannot use toxic things there).

The maintenance tasks I would like to do in short term:
  - Adjust the breaks/gear/seat post/etc. as it is necessary.
  - Regularly clean the chains
  - Fix a flat tire

The tasks I would like to do medium term (if I need):
  - Fix a slightly warped and twisted wheel
  - Fix the lightting
  - Rewire the breaks/gears if it is necessery

I have no tools at all, so my question is that what tools I have to buy in order to be able to maintain those bikes in short term?

I live in Switzerland close to the Alps so the weather is quite wet (e.g. I assume that I need different oil for wet weather than for dry weather).

Thank you in advance!

(Updated according to the admin requirements)

Lennard Zinn has written books on maintaining road and mountain bikes (a trekking bike probably falls under the "road bike" category in terms of maintenance). He lists four levels of tool kits based on how ambitious you want to get with servicing your bike. I think this is a reasonable approach, especially since we don't know how ambitious you want to get servicing your bikes in particular.

Also, to some extent, a tool's necessity will be determined by what kind of bike you have, for instance, my road bike has no torx bolts; with a carbon bike, a torque wrench is probably more important. So any advice also needs to be tempered by the bike you're servicing.

Multitool is enough. Other to do in bicycle workshop.
Also patch comlect. Pump. and teargas ballon for stupid dogs )))


Normal for derailleur to make noises? I have a giant anyroad 1 2015.  It has this as components
Crankset    Shimano Tiagra, 34/50
Cassette    Shimano Tiagra 11x34, 10-speed

That is 7 cogs in the cassette, and 2 cogs on the crankset.

Is it normal for the derailleur to make noise when the chain is on the smallest cogs? It also happens a bit when the front derailleur is on the smallest cog, and the rear one is on the second-smallest.

Yes - I understand you're not supposed to do this - your chain should try not to twist. My question is this - is this normal? Or is it just a poorly installed/adjusted derailleur?  My rationale is that it should be 'silent' on any combination of gears since the bike was built to do this.

Is the question is it normal for a it to make noise when cross-chaining from smallest to smallest which you're not suppose to do?  Yes, but by doing so you are putting more stress on the chain and cogs, it is bad for your drive train and can result in dropping a chain or mucking up your gears faster than normal.

It is likely making noise because it is rubber or grinding on the derailleur or chain set.

The bike was not made to do that, you said yourself that you know you are not suppose to do it.

"My car sounds like crap when i run it with zero oil in the engine.. is this normal?"

It's not normal, especially if you have only a double crankset!

I've set up triples such that they have no noise in any combination. And that's cheap components. Think 8 speed bike with Shimano Altus FD, thick 6-8 speed chain.

I recently set up an incorrect front derailleur on an 8 speed bike, with its original shifter: a Shimano SLX "Dyna-Sys" FD for 10 speeds. Using a 9 speed chain and some tinkering, plus a very slight unorthodox rotation of the derailleur around the seat post away from perfectly parallel (it's a clamp-on, not direct mount), I got it so that it has no noise on the middle and small ring, any cog, and only a bit of chain rub in the largest-cog-largest-ring combination.

If mismatched hacks like this can be made to work, there can be no excuses from the bike shop selling you a brand new bike for over $1000, in which components should match, and be properly set up. They are not a department store; they should know what they are doing.

From the fact that you have a rub on the smallest cog, which progresses to the second smallest cog when you shift the FD to the left to the middle ring, suggests that the FD is positioned a little too far to the left: either it could use a little more cable tension.  What you can do is relax the high/low trim screws and get it as good as you can on both rings by cable tension; then play with the trim screws.


Right hook accident scenario: who is at fault? I just got into a collision with a biker while driving my car. I have read a lot about these types of accidents, but none quite cover the circumstances that were present in my case and I’m wondering who is at fault.

I was stopped at a red light in a line of cars. I was probably the 5th car in a line of 8. The intersection was at the bottom of a hill on a one-lane road with a bike lane on the right side. I had my turn signal on at the red light and when it turned green and I got to the intersection I turned right. As I began my turn, I collided with a biker who was going much faster than me but approaching from behind, and was trying to go straight through the intersection.

The short version is that I was trying to turn right in a line of cars when the biker who was behind me struck the side of my car as I was beginning my turn.

Luckily the biker wasn’t hurt because I wasn’t moving very fast and he just clipped the edge of my car instead of actually hitting the side. He just had a few scrapes, thank God.

I don’t know what to think in this situation because I was in the rightmost lane with my turn signal on, in front of the biker but, on the other hand, it makes sense that he wouldn’t be able to see my blinker very well because of the line of cars and I could have seen him if I looked in my side mirror.

EDIT:  I can't believe this has gotten so many responses.  Thank you all for your thoughts.  A few people have been asking about where this happened.  It happened in California, USA.  A lot of people here are saying that they are thankful that things didn't turn out so bad, at least not nearly as bad as they could have.  I completely agree.  When I was helping the biker up, he said "That's the last time I come flying down that hill" and I responded with, "That's the last time I turn without checking my side mirrors".  So hopefully we, and anyone else reading this, can at least be thankful that it was a learning experience and that we can all be safer in the future.

One more thing.  Because the light had recently turned from red to green and I was in a line of cars, there seemingly was no way for the biker to safely go behind me and pass on my left, as there were a few other cars behind me.

Also, thank you Rider_X for the awesome and comprehensive response.  I come from an area where there are no bike lanes so I didn't realize that you are supposed to move into the bike lane before turning.

You will likely be found at fault. Bicycle lanes are considered a lane of traffic that supports only one type of traffic for extended periods of time (i.e., bicycles). As such, by your description you signaled your intent, then turned right across another lane of traffic and collided with another vehicle  already occupying that lane. It is your job to ensure a lane of traffic is clear before entering it.

If you were talking about two car lanes I think there would little if any questions regarding fault, but because we are talking about cycling many motorists assume it is the job of the cyclist to get out of the way because they are more vulnerable. While true from a practical perspective, this perspective is not supported legally.

Further confusing matters, in some areas  (e.g., North America) drivers are required to merge over into the bike lane (when safe) before turning, while other areas of the world do not allow any merging and instead give the cyclists the full priority at all times. Regardless, both approaches would find legal fault with the motorist turning across another vehicle lane (i.e., the cycling lane) when it was not clear to do so.

So what should you have done (North America)?

Generally in most North American jurisdictions if the bicycle lane is clear you should first merge over into that lane before making a right turn (see diagram below). This merge area is often indicated with dashed lines separating the car and bicycle lanes. If you safely merge over, then you have physical position over the cyclist and they should wait until you complete your turn before passing if they wish to remain in the bicycle lane, otherwise they will need to change lane into the main traffic lane to the left to pass (assuming of course a jurisdiction that drives on the right).

While you had your signal on you were still in the lane to the left of the cycling lane (i.e., left of another vehicle lane) and as such you had only signaled your intent. Until you safely enter the cycling lane, to complete your right turn, it is expectant upon you to check for traffic before moving to the right.

From San Fransisco Bicycle Coalition

Other North American Jurisdictions supporting this approach

I chose the figure above because it clearly communicated the concept. Some might be concerned that this only applies to San Francisco, but similar rules apply in many other North American regions. Some further examples are given below:

Ontario, Canada

  Diagram 2-12

  Bike lanes are reserved for cyclists. They are typically marked by a solid white line. Sometimes you will need to enter or cross a bike lane to turn right at a corner or driveway. (See Diagram 2-12) Take extra care when you do this. Enter the bike lane only after ensuring that you can do so safely, and then make the turn.

  -The Official Ministry of Transportation (MTO) Driver's Handbook

British Columbia, Canada

  Where there is a broken line marking the cycle lane at the approach to the intersection the driver may move over to the curb into the cycle lane prior to making the right turn in the way that most people are used to. Drivers doing so are making a lane change and must yield to cycle traffic in the bicycle lane before moving over! In this situation, the cyclist must wait behind the vehicle until after the turn is made to clear the cycle lane.

  -DriveSmart BC

California, USA

  21717.Whenever it is necessary for the driver of a motor vehicle to cross a bicycle lane that is adjacent to his lane of travel to make a turn, the driver shall drive the motor vehicle into the bicycle lane prior to making the turn and shall make the turn pursuant to Section 22100.

  California Law

European Jurisdictions

European jurisdictions give bicycle lanes legal vehicle status, but what seems less clear is if there is support for motor vehicles merging across bicycle lanes before a right turn (if driving on the right). From the comments it appears most European nations give cyclists the absolute priority (i.e., the driver needs to wait until there is no cycling lane traffic before turning).  Explicit examples are still needed.

Germany (by sleske)

In Germany, you would be at fault (probably fully). If you make a turn (no matter whether right or left), the traffic behind you in other lanes has priority, and you must make sure you do not obstruct or endanger it before turning.

This is based on §9 Straßenverkehrsordnung (German traffic code):

  Abbiegen, Wenden und Rückwärtsfahren [...]
  Vor dem Einordnen und nochmals vor dem Abbiegen ist auf den
  nachfolgenden Verkehr zu achten; vor dem Abbiegen ist es dann nicht
  nötig, wenn eine Gefährdung nachfolgenden Verkehrs ausgeschlossen ist.

Translation (mine, no guarantees):

  Turning and reversing [...] Before changing lanes and again before turning,
  drivers must look out for following traffic; this is not necessary before turning
  if a danger to following traffic is not possible.

Southwestern Pacific

New Zealand (left hand traffic)

In New Zealand cyclists appear to have absolute priority as turning motorists are not allowed to merge across the bike lane to make a turn and are required to wait until the bike lane is clear:

  When there’s a cycle lane at a set of lights, you must not wait in it for the light to turn green, and you must not drive in it as you approach the lights (unless you’re riding a bicycle). Motorbikes must not use this lane, either, but they can filter between stationary traffic.

  Cycles have the right-of-way in this lane. If there are cycles waiting to go forward, you must give way to them before you can turn left.

  The car is waiting in the wrong position, blocking the cycleway

  This shows the correct position with the left-hand wheels of the car not encroaching into the cycle lane

  -Driving Tests NZ

You are always at fault if you hit a someone riding a bicycle, IMO.  I see and am involved in this situation a lot - in bike lane on right side of road (US traffic) flying, and someone in front of me decides to take a right.  Normally, they will wait for you if they are paying attention.  Other times they just turn and pay no mind to the rider (sounds like this is what happened).

So, as a driver, don't do that.  Just wait until they pass you unless they are obviously slowing and waiting for you to turn.  If you pinch them taking a right, you are at fault because you just hit a person with a vehicle.  Whether you are in legal trouble is another question that depends on a bunch of things that a legal professional would know better.

As a rider, when I'm in this situation and going fast as you described, I usually pull into traffic behind and to the left of the car that's turning right and just pass them in their own lane as they peel off.  This helps the driver see me as I am now directly behind them.  If they decide to turn early or I can tell they aren't paying attention, I pass.


Rehabilitating leg warmers I have a pair of leg warmers, purchased from Performance Bicycle some years ago. They're still in decent shape, but the rubber or silicone layer at the top that holds them up has thinned. The warmers tend to slide down my leg these days.

Is there a way to re-create the layer that's meant to grip them to my legs?

This stuff is not expensive.  Simply unpick the stitching, and replace it.

The hardest thing will be doing the stitching in a way that will stretch, because a plain straight stitch will not work.  A fancy modern sewing machine can do these stitches, as can an overlocker.

Example pricing seems to range from a few dolleurosuid to tens of them.  It gets cheaper in larger lengths, with 50 metres being under $1 / metre.

https://www.aliexpress.com/w/wholesale-silicone-gripper-elastic.html  for example.  Keywords here are "silicon grip elastic"

The most important part of the leg warmer IS THE silicon that grips to keep them in place.

Time to replace the whole leg warmer.


Would you ride with this tire with cuts in the sidewall? I have a next to unused GP5000 road tire, 25mm, which unfortunately has three cuts in the sidewall. I would like to ask, if it these constitutes a safety problem - or if they rather are to be looked upon like regular cuts in the tread.
What is the verdict: dead or not dead?
Thanks,
Morten

I would not ride that tyre.  Pretty sure I can see tube in the second photo, and that's asking for a sudden blowout.

You might choose to put a boot/patch on the inside of the tyre, and use this as an indoor trainer tyre only.   Might be okay on rollers, would make a great front-wheel tyre for a direct-drive trainer (ie, the wheel that doesn't turn at all.)

I certainly would not ride on the road with that ever.

It is dead, buy a new tyre.

Of course not.

Why are you risking your life on the word of a bunch of internet strangers you're never going to meet or be able to hold accountable?

Go to a qualified specialist and have the suspect tyre examined…

Whatever else, please remember that if it does fail and any kind of law-enforcement finds out you Posted this query, you will have no weakest wheel to stand on.


Replace v-brakes with disc brakes I would like to know whether I can replace my old v-brakes with disc brakes. Do I need to also change the wheels or something else?

You need to have the appropriate mounts on the fork, the rear of the frame, and you need hubs that can accept disc rotors.
My understanding is that some older MTB frames and forks had mounts for both V- and disc brakes. This was when the industry was starting to shift towards disc brakes. While I'm not familiar with MTBs, that might have been in the early 2000s. If you don't have the correct frame mounts, then there's obviously no way to proceed at all.
Even if you do have disc mounts on the frame and fork, I suspect your hubs were rim brake only, so it would be quite a costly upgrade. It's likely more economical to sell the bike or repurpose it as a commuter.

I would like to know whether I can replace my old v-brakes with disc brakes. Do I need to also change the wheels or something else?

Yes, you need to change the wheels -- or at least the hubs (and possibly spokes too).
You also need to change the fork.
Not to mention the frame.
Also the brake levers are useless unless you buy mechanical v brakes with long pull ratio (if you have short pull mechanical brakes or hydraulic brakes they won't work with your existing levers).
Furthermore, if you are switching to hydraulic disc brakes (the best disc brake technology), you need to change the inner cables and outer cables with hydraulic hoses and hydraulic fluid.
You also need to purchase brake rotors as a new component. And the disc brake calipers of course (they usually come with brake pads -- if not, you need to purchase brake pads too).
I'd say the list of changes needed is so large that actually you'll end up using a very small fraction of your current bike. Changing the frame might change the list of compatible components, so there could be some components needing change that I didn't list.


Why are BMX saddles so low? I've seen a lot of teenagers riding BMX bikes recently.

It seems that most if not all of the guys I've seen riding their BMX bikes around the streets, car parks, local parks, etc have a frame that's really small, and a saddle that's as low as possible.  It looks like the rider's knees are above their waists for much if not most of their stroke.

One of the local parks has a dedicated BMX track with actual racing taking place on it.  When I watch those guys they never seem to have their saddles all the way to the bottom.

The thought occurred that it might have something to do with trick riding but none of the kids with bikes set up like this seemed to actually be doing tricks. They'd just be riding the bikes normally or even just sitting on them outside shops. Their bikes also didn't seem to be set up with trick riding in mind, most of them didn't have those bar things projecting from the wheel hubs for the riders to stand on.

Is this really low saddle something they're doing to be cool? Or are there some real tangible advantages to this seating position?

Low seats provide clearance for more acrobatic body movements. This is essential for bunny hops and nearly every other trick which builds off of this skill. If you look at trials bikes they similarly have lots of clearance for the rider over the frame and the saddle. Since speeds are relatively low, and long distance riding is not the goal, pedaling efficiencies gained by a higher seat position are much less of a priority than vertical maneuverability.

As per Daniel R Hick's comment BMX bikes are also commonly used for children's bike's as they are easy to learn on because of the low seat.

In this case fashion follows function. Just because the particular riders you see aren't tricking doesn't mean there isn't a valid functional reason for this kind of setup.

I'm an actual bmxer who does tricks and all sorts of other things. I can give you the BEST answer on here. People with low seat usually have them like that to keep them out of the way during tricks. Imagine throwing a tailwhip and having the seat catch your foot then you don't land the trick. Kinda why. Haha. Also high fatter seats indicate they do or are learning barspins. Cheers.


About 20-30 people bike to where I work. What equipment/supplies should we have on hand? I work in San Francisco, and I'd estimate about 20-30 people bike to where I work. We mostly have a mix of road bikes and hybrids with a couple commuter bikes and mountain bikes too.  Currently, the only equipment in our bike cage is a locking entry door, a double-decker bike rack similar to this one, and a single floor pump.

I was thinking that we could start with some basic toolkit or repair kit, spare batteries for lights, loaner headlights and tail lights, and maybe a couple loaner helmets so people don't have an excuse to ride without helmets.

What else should we stock?  Are there premade kits for a situation like this?

I'd maybe ask the cyclists themselves - maybe ask them to bring useful spares and have an amount of petty cash on hand to reimburse them. They might be able to bring in old lights (let's face it many of us always leap to the newest kit and have drawers full of old kit lying around).

The basic tool set should include tyre levers, an adjustable spanner/wrench or combination bike tool, Allan keys (hex wrench).

If you're prepared to keep things topped up with consumables as well, that would be great - but you'll be forever replacing the inner tubes, but while you might need a mix of sizes, starting just with a few 700x25c would work.

I'm not convinced about spare helmets - apart from the whole obligated helmet wearing debate - you might be opening yourself up for liability if someone got badly injured in an accident while wearing one of the loaner items.

Many lights these days are rechargeable themselves, either through USB or directly to mains, so making sure that there are charging sockets and a charged USB hub could be good, maybe a battery charger would encourage people to switch to that style of battery.

I noticed @Benzo mentioned zip ties in his answer.  I think those are indispensable. All the lists are very good.

I would add 1,000/100 mile an hour tape, or duct tape.


Why are wheels so important for racing? I hear/read everywhere that if you can spend some extra money on the bike, buy better wheels. can someone explain for me why?
Is it because they are rotating or are there other comfort factors?
thanks

Wheels and tires are the interface between the bike and the road; and are the parts that take the most stress (wear and tear) along with the bottom bracket. (IMO)

lighter wheels will reduce the rotating mass (rotational inertia); you will need less energy to make the wheels accelerate/decelerate.
higher quality bearings in the hub will reduce friction.
better aerodynamics in the rim and spokes (less energy needed to cut through air)

IMO, In the end it all matters to weight.

If you are doing serious cycling (i.e. keeping time, strava segments, ... ) it might be a good upgrade; but if you are a little less serious about it, maybe just an expensive christmas gift to self. :-)

Less rotational mass can be felt immediately, even 200 grams.  It would be incredibly evident right away in acceleration.  The number one thing I hear people say after buying stock bikes is they got a new wheelset and "it feels like a new bike".  Now, it's been proven why complete with formulas.

https://www.wired.com/2016/06/cycling-physics-extra-mass-bike-wheels-enemy/


Get a tougher gear on Shimano GRX, 11-34T, 2x11 I have a new 2021 Cube Nuroad Race gravel bike with Shimano GRX, 11-34T, 2x11.
I am used to riding a road bike, and find on the new one I don't need the easiest gears on the hills, but could use a tougher gear on the downhill as I can't get any power down when descending. (I have switched the 40mm tyres for 32mm tyres while the weather is still not half bad in the UK).
I have never messed about with the cassette on a bike, switching gears etc, and was wondering how to go about it. Do I need to buy a whole new cassette? What cassettes are suitable and compatible?
Thanks
Edit:
Some useful suggestions. For more information, it is not just pedalling down serious slopes that I run out of gears, but on not very steep descents and occasionally on the flat if my speed is up. Though it seems what I need is to switch out the chain rings.

You cannot get a higher gear ratio by replacing the cassette. The 11 tooth sprocket is the smallest you can get on a compatible cassette. (Systems with 10 tooth sprockets exist but use a different freehub design).
The issue is that you have 46/30 tooth sub-compact chainrings (I looked up specs here). Which are giving you the low ratios. This is common on gravel bikes as they have larger diameter tires run at lower pressures and are designed to negotiate rougher surfaces. A road bike typically has 50/34 or 52/36 tooth chainrings.
If you want higher gear ratios you have to get larger chainrings. GRX 2x11 cranks only come in the 46/30 size. You may be able to find larger rings made by another manufacturer that fit the GRX crank, or you get a whole replacement crank with larger rings.
If you still want to know how cassettes fit on hubs see this Park Tool video. There are a few standards for the freehub that the cassette fits on. Shimano's HyperGlide II is dominant and also used by SRAM. Campagnolo has their own standard. Systems that permit 10 tooth sprockets like SRAM XD and XDR are becoming more popular. In addition to the freehub attachment the cassette sprocket tooth range has to fit inside what the rear derailleur can handle. This includes the max sprocket size and 'total capacity' (difference between chainring tooth counts plus difference between largest and smallest sprocket tooth counts).

I am used to riding a road bike, and find on the new one I don't need the easiest gears on the hills, but could use a tougher gear on the downhill as I can't get any power down when descending.

Don't pedal down hills.
Seriously, when riding downhills your main concern is air resistance.
For example, a bicycle speed simulator I wrote in Matlab tells that in certain downhills (minus 5% grade), I get 57.1 km/h speed when not pedaling, i.e. coasting.
For the same downhills, if I manage to reduce my frontal area by 20%, I get 63.8 km/h.
If I manage to pedal with 150 watts extra power, but the rapid pedaling creates air swirling that increases the air resistance by 10%, I get 58.4 km/h speed.
Most of the benefit of pedaling went away due to the air swirling increasing air resistance. In fact, by pedaling I get 2% extra speed and by optimizing my position to minimize frontal area I get 12% extra speed.
The position that minimizes frontal area is not a very efficient pedaling position.


What might be causing rear casette to creak? So I'm a bike noob in terms that my bike is certainly new, and since I bought it I've had problems with it.

So this time, I've figured where the problem comes from, it's the rear casette exactly, once it's under load, it makes a creak sound, which at high speed, sounds like a click, and in the past used to be just a click, very loud, it has been reduced to a softer creak now; let me make a timeline of important events.

It was clicking awfully and louder, when on load.
The bike shop changed the freewheel.
It started creaking softer, still would click at fast speeds.
The bike shop changed the pedals, bottom bracket.
Nothing happened, it was still the same if not worse.
I started playing with the rear cassete and derraulier, it got better for a little while; it got fixed the day it rained, somehow.
Creak/click is coming back, I found a way to replicate the load, and it replicates the sound, definitely the cassette; even grabbing the casette and rotating it with your bare hands makes the same sound; I was not strong enough with only one hand to do it in the video.

What do you think it is? should I complain for the 7th time in the bike shop but this time tell them exactly what it is? anyway the more information the better, so at least I can talk with property.

Here's the video where I show my homemade attempt.

Also I'm surprised this is exactly the same exact sound that it does when I climb (thanks youtube):

             this is 100% the same.

It sounds like you have isolated the issue to the rear wheel, and probably the rear hub.

I doubt that that cassette or it's attachment to the freehub body is the cause of the problem. It may be the freewheel assembly, or the hub bearings, or even a crack in the hub body.

To rule out the cassette, you could replicate the creaking using a chainwhip tool as show in your second video, then remove the cassette and see if you can replicate it by torquing the freehub body. It sounds like you don't have the tools to do this though. Do you think you could you work with a repair technician at the bike store and have them use a chain whip tool demonstrate the creak with the wheel out of the bike?

You say the problem has existed since you bought the bike. Were all the previous unsuccessful attempts to fix the problem performed for free by the store you bought the bike from? (In order to make good a faulty product that they sold you) If so, you can try requesting that they replace the entire rear wheel, or at the very least the entire hub. You may or may not have success depending on how long ago you bought the bike and warranty it came with.

I have exact same problem and gets exact same noise when I do something like that.
I started to hear this after 3rd rides (after 2 water washing of MTB).
I also do not hear when it rains or when I spray WD40 but it only last about 10 minutes or so as WD40 dries off, creaking sound come back.
I tried silicon lubricant only to help little.

Did you find the answer?
Let me know if you did.  I'm thinking about taking the cassette apart and reinstall with new grease but haven't got around it.


Help to find the history of my 1900's Armstrong cycle :) Pretty new to the whole vintage bike thing so would love a bit of help finding the history of the bike I bought in Walthamstow, London, last year.

It's marked to be an Armstrong Cycle, Birmingham, which I have found a lot of information on, but mainly around the 'moth' models and tandems - I can't seem to place the 'Havana'. I'm looking to find the approx date of creation, and perhaps a bit more about it's stand-out features.

Here's some pics.

It's got the original seat, bell, lights and 3 gears - it's in great working order.

Any help would be much appreciated :)

Charlotte

From http://www.bikeforums.net/classic-vintage-bicycles-what-s-worth-appraisals-inquiries/850018-1957-armstrong-havana.html it looks like it could have been made form 1957 to 1961 or later. It looks like it has a 3 speed internal hub gearbox, probably a Sturmy Archer, as it is British made.

Appears that Armstrong was part of a larger group by this stage, and the ealier design approach may have changed a lot.

If you look under where the pedals are (the bottom bracket), there is often a serial number which may contain the year of manufacturer. Or it could be stamped elsewhere on the frame.

Definitely an Armstrong Havana, late 1950's.  It was my first proper bike.


Are all folding pedals a bit... bendy? I have recently acquired a folding bike.  One of the most irritating things is the folding pedals, as pictured:

Pedal in folded position

Pedal in deployed position, ready to ride

Close up of pedal latch - this image shows the sliding latch in the middle of the platform that holds it in place.  To fold, you insert finger into hole and slide the middle section outboard.  This pulls two tabs from a slot in the silver metal part, and the pedal platform is free to rotate up/down

When pedalling normally, it feels "okay"  but when exerting some force on a climb I can feel the pedals bend under the load.   It gets much worse when out of the saddle.

If I were to estimate, it might be a 10 degree deflection of the pedal body from the pedal axle center line.

To minimise the effect, I've made a conscious effort to put the ball of the foot on the silver metal part, which feels much more solid than the rest of the pedal.

So my main question: Is this normal for folding pedals or should I be exploring for folding pedals that are more solid?

Or do I simply fit normal pedals?  This may interfere with the folding function on the left crank, and will leave the right one poking out more as a shin-collector.   On the plus side, clipless.

Yes, I've used a variety of folding pedals on my Dahon and Brompton and they're all a bit flexy. I've had plastic ones snap in half on me (and yes, that can be very painful/dangerous). The best ones I've had were all-metal ones in which the axle and folding pedal were both metal. But even those aren't as strong as fixed pedals -- and none of the folding designs are designed for putting all your body weight on (by standing to pedal).  This is the MKS FD-7, perhaps the solidest of the folding pedal designs, but also quite heavy:

Instead, the best pedals sold for folding bikes are the removable axle pedals made by MKS and others. Rather than the pedal folding, the pedal axle disengages from the crank with a quick release. This removes the folding component  and so this type is stronger and more rigid. The other advantage is that you can also get clipless as well as regular pedals. But even with this design, the pedal will still remain the weakest link in your power chain. The removable axle thins where it enters the crank (which means that the bearings are also smaller) and that the pedal retention system while improved and generally bulletproof is not foolproof (they keep making better fools).

Here is their regular style Ezy pedal:

The ideal design would involve cranks that had a custom pedal quick release built into them  but that would mean you wouldn't be able to use standard pedals anymore and would be locked into that manufacturer, which makes me wonder why Shimano hasn't done this. :)

You could also just use your standard pedals and bring along a wrench.


Bike pulses while applying the front brake. I'm unsure what the cause is Once per rotation of the front wheel, when braking, the bike pulses under me. The brakes are calliper rim brakes.

Swapping wheels out fixes the problem - so it is definitely wheel related
The wheel is true
I can't see or feel anything different on the brake track.
I have tried cleaning the brake track with degreaser and rubbing alcohol with no luck
I have also sanded the brake track to try to remove anything that could be on there.
I have measured the rim all the way round - exactly 19mm rim width the whole way around.
The pulsing does not occur when the brake goes over the rim joint.

And it's still happening.

Any suggestions?

Measure the rim in a more accurate way for starters. Even 0.1mm can cause a change in the braking power.
Also, with the bike resting on its handles and seat, flipped over, ask someone to lightly hold down the front brake while you slowly turn the wheel and figure out exactly where the trouble spot is and how big it is. If there is no visible difference, and you don't have the means to measure the rim more accurately, then it probably is the width of the rim being uneven. On the other hand if you find that it does not occur at the same spot every time, maybe the problem is elsewhere.
If you can, see if the width of the rim changes radially, fatter near the tire and thinner near the spokes. If the difference in this width isn't constant, it could be causing the problem

You need to toe the brake pads in. The pads are hitting the rim unevenly and causing vibration. I have had to do this many times on my CX bike. The pads need to hit from the front of the pad first, this reduces the chance of vibration occurring. Also using Swissstop pads will help greatly.


Brand new bike. Briefly removed the rear disc brake caliper, now it's too tight I have a 2017 Cannondale Synapse Carbon Disc 105 with less than 10 hours of ride time on it. (I got it in March as unsold stock from last year) I noticed that after I had ridden for a little while, the rear wheel started squeaking obnoxiously as I rode, even while coasting. After a bit of troubleshooting (i.e. removing the caliper), I determined the rear disc brake was definitely the problem; it was presumably misaligned or something. However, when trying to reinstall the caliper after learning this, I noticed the pads seem too close together, to the point where I had trouble fitting them back around the rotor. Now that I've roughly gotten the rear caliper into position, it is constantly rubbing against the rotor however I align it, and the brake lever feels much tighter. Again, this is a new bike with new Shimano 105 parts and I haven't changed anything out. What happened? How do I recalibrate the brake so it works properly? (If it turns out I somehow ruined something, I still have a warranty tune-up at my dealer where I can get it sorted out)

As mentioned in comments you most likely applied the brake without the disc between the pads. The pistons advance and do not return all the way to their original position - this is how hydraulic brakes automatically adjust for pad wear.

The pistons can be pushed back in. Remove the pads then use a tire lever to push the pistons back in. Then replace the pads. You should be able to find numerous videos showing you how to do this on YouTube.

You should check your disc is not warped, and then reinstall the caliper unit. Again there are plenty of how-to videos explaining how to align the caliper. One way is to loosen the caliper bolts, apply the brake so that the pads grip the rotor them tighten the bolts, then release the brake.

Maybe the bike has a factory marriage. It is better to take it to the dealer. We all know that an independent intervention to eliminate a marriage leads to the invalidity of warranty service.


Preparation/tips for 50 mile ride I've been cycling for most of my life but I'm not an endurance rider - the furthest I've ever cycled in one go is 20 miles. I do a modest amount of riding daily - a couple of miles. Soon I'll be leaving my home for a work placement (I'm a student) and the trains are extremely expensive to come home on every week, so I'm considering cycling instead. The terrain is almost entirely road with occasional dirt tracks, and my bike is a MTB Cycletech mountain bike. The first question I have: is this 50 mile ride feasible for someone of my experience? Secondly: if so, what sort of preparation should I be doing? I'm thinking of bringing several bottles of water, but I'm unsure as to what foods would be sensible to bring, and how much of them I should be consuming. Any other tips on top of this would be extremely useful.

50 miles is feasible but it will be hard work.  Think about how tired you felt after cycling 20 miles. Then cycle 20 miles again from that tired start and think about how tired you'll feel then. Then, cycle another ten miles.

The other answers give lots of good advice which I won't repeat. Since you mention trains and coming home every week, I assume that your plan is to cycle home on Saturday and then cycle back to the place where you work on Sunday.

While I think you can do 50 miles in a day, I doubt you can do 50 miles twice in two days. You should seriously consider taking the train one-way, so you're only cycling 50 miles once a week. This also has the advantage that you could travel home on the train on Friday evening and get more time there. The problem is that British one-way train fares are often almost as much as the return (e.g., when I take the train to visit my parents, the return fare is £104 and one-way is £103; no, that's not a typo, seriously, it's only a pound cheaper).

So, I propose this. One week, buy a return train ticket on Friday or Saturday and take your bike home on the train; cycle back to the place where your job is on Sunday. The next week, cycle home on Saturday; take the train back on Sunday. This works because the return half of your ticket is valid for a month. When you feel you can cycle twice in the same weekend, start doing that.

I don't think you need anything special for the ride apart from having to eat and drink something. I have ridden 100 km which is bit over 60 miles, and used to do plenty of 50 km (bit over 30 miles) rides. The 50 km rides are manageable even without a water bottle as long as you aren't riding in a very hot environment. However, for 50 mile ride, I would plan to at least drink something and very possibly to eat something. You don't need to carry a water bottle with you (it's just added weight), if there's a possibility to stop at a grocery store to purchase something to drink. However, if there are no grocery stores near your route, do carry a water bottle.

Instead of carrying a water bottle, I recommend using the saved weight to carry a basic toolkit with inner tube patch kit, a spare inner tube, tire levers, Allen keys, a small chain tool and chain pins suitable for your chain. Don't forget a pump (I recommend Quickex Quicker Pro).

None of my rides were with special cycling clothes. I just used some casual sports clothes. With synthetic fibers, of course, as cotton would just become very wet.

All of this assumes you are comfortable with your bike and everything is adjusted properly. If you have been riding for shorter distances, this probably won't be an issue.

You will be exhausted after 50 miles, but trust me, it will feel like a great accomplishment.

If you're planning to do these rides often, consider checking whether your tires are good for the conditions (I recommend 28mm wide slick tires, as they require less pressure than 23mm tires and thus are easier to inflate, and additionally 28mm tires don't require extra-narrow rims like 23mm tires do, and 28mm in wet sand is better than 23mm) and whether you are using a bike with drop bar (recommended for its versatility and possibility to ride with a very low air resistance). Also, shoes that attach to the pedals are recommended. Don't choose racing shoes that cannot be used for walking!


Heavy Rider (300lb+) - Please recommend a 26" tyre to avoid tyre pinch I ride a hybrid on 26" rims currently fitted with hybrid tires.  As I am 300lbs+ the rear tire runs permanently deformed/flat and the rims ride over the rubber causing tire pinch.  Can anyone recommend the tyre tube combination that I should try to obtain that will stop this happening?

As a heavy rider personally, I don't have many issues with flats.

A normal tire on the high/maximum pressure works fine to avoid pinch flats.

The key is to check tire pressure every time you get on the bike. Even a day will allow a tire to soften 10 psi, and that will allow flats to occur.

Road hazard flats are not avoidable except by avoiding the hazard in the first place. :)

Edit: to be clear, my answer is that it is most likely that your existing tires are not fully inflated, rather than that a different tire is needed.

just pump it on bigger pressure, then two things can happen;
1) inner tube won't be able to hold pressure -> buy some inner tubes for downhill
2) tyre jumps out of rim -> buy some rims for dirt jumping/downhill, they will hold the tire better


Is there a difference between mountain and road stems? I see them advertised as being good for one or the other. Is there really a difference? Or is it just a marketing gimmick?

The biggest difference is strength. There are some road stems that will say they are not recommended for downhill/freeride type riding, but are ok for cyclocross. Road stems will also come in a larger range of angles.

Just be sure that when you are looking at stems, you match the clamp of the stem to your steerer tube (1" or 1 1/4" usually) and to the diameter of the bars that you are using.

Whether 1" or 1 1/8" stems there is no difference.

"Road stems" typically have more shallow rise (between 6 degrees and 20).
"MTB stems" typically have more steep rise (between 17 degrees and 35).

Of course the materials can be different and you want to choose the correct materials for your application, but most modern threadless systems have identical steerer tube size (1 1/8") and handlebar clamp size (31.8mm).


Are disc brakes weak? And what is "bedding in"? I've owned a couple of department store bicycles in the past with caliper brakes and I set the brakes up properly so when I squeezed the brakes the bike stopped pretty quickly.

I test-rode a bicycle from a bike shop a couple of days ago which had disc brakes, and it was just so slow to stop the bike, it seemed like the brakes were so weak. I checked the brakes on the spot by standing next to the bike and squeezing the front brake and pushing the bike forward, and there was no slippage, and same with the rear wheel. So I think the brakes were set up correctly, they just seemed to have no stopping power.

I asked the clerk about it and he said they would need to be "bedded in". I couldn't understand what he was talking about, but is it normal? And why can't I get a bike that's ready to go from when I buy it. Do I just buy a bike with weak brakes and use it for a while and after a few days the brakes will work better after it grinds a groove in or something like he said? Or were the brakes not set up correctly?

Bedding-in is a common process with new disc brake pads. Disc brakes were developed much earlier for motorcycles and cars, from which the technology and the terminology has been transferred to MTBs: see https://ebcbrakes.com/articles/motorcycle-bed-in/ and http://www.centricparts.com/files/White%20Paper%20Revisions%204-2012/Centric%20White%20Paper%20C3-2012-Bed-In%20Stock.pdf

Bedding-in is a process in which both the pad surface microstructure but also the surface composition of the rotor is affected. During the run-in a very thin layer of material is transferred from the pads to the rotor. This surface deposit increases the brake power significantly.

However, even when the brake pads are not yet bedded-in, a disc brake should have more stopping power than a rim brake. So I wonder whether the surface of the rotor or possibly the pads have inadvertently been poisened by a lubricant. Ask the seller to clean the rotor with alcohol.

I believe bedding means letting the brakes wear out slightly so it sits perfectly on the disc because the disc is not completely flat and neither are the brake pads.


Shimano Hydraulic brake 90-degree angle hack Does anybody know of a way to get Shimano Hydraulic brake hoses to exit the levers at a 90-degree angle?

I ride a recumbent and at the moment I have to put up with a huge loop in front of my eyeline to get them down the steerer. If it came out at 90 degrees, it would clip direct to the steerer, look neater and probably be a bit more aerodynamic.

Could I just fit the same connection as is used to enter the calipers?

If you are willing to switch to a Zee, or Saint, brake the hose is connected at the caliper via a banjo-style connector, which allows for usually about 270deg. of motion around the axis of the fixing bolt. Many brakes use this kind of connector, but on Saint and Zee models, the fixing bolt is parallel to the caliper mounting bolts and pads, allowing the hose to be positioned at a 90deg. angle from the caliper, as seen from above. I'm not sure which direction you want the hose to point, but other brakes have the fixing bolt in other orientations. SLX and XT have it perpendicular to the previously mentioned models, so the hose pivots parallel to the pads. Tektro/TRP, Sram, Formula, and Hope all make brakes with banjo fittings. Check photos of the calipers, there's definitely something out there that cant point the direction you want!

You can try cutting the hose down in length, provided it is still a safe length, then zip tie it to the frame.


What are the pros and cons of internal gears? I've had my hybrid 24-speed for a bit over 3 years now, and just last weekend, when looking for a bike for my wife, discovered internal gears. Suffice to say it blew my mind when I saw 7-speed internal gear hubs, for example on this This Giant Suede Women's bike.
So the question is, what are the trade-offs between the internal gear hub and an external gear hub and derailleur?
I'm assuming they'll be more expensive? but what about the set of gear ratios they provide? the reliability? the serviceability? tuning/maintenance? other effects on the chain/sprockets?
Going back to the bike linked above, there's a near-identical model (picture) with 21-speed external gears that's considerably cheaper, and I'm wondering whether the extra money for the internal gears would buy any real benefits (e.g. longer lasting chains/sprockets or fewer services), or whether it's just for fashion?

The main advantages of hub gears over a 1xN derailleur system are reliability and being able to shift while stationary. Since there's no derailleur or chain tensioner it's easier to add a full chaincase which means chains last a lot longer and with mudguards added there are no dirty bits accessible on the bike. They're heavier and harder to maintain if you have to maintain them.

There's a whole style of bike that uses those advantages (and others) and from a US perspective is called a "european" or "dutch" bike. Broadly, it's a bike built for someone who is not a cyclist, rather they are someone who uses a bike for transport. It should just work, no special clothes or rituals required.

Compared to a 3xN derailleur system a hub gear is much simpler to operate and maintain. All the gears are in order and you only have one shifter. The compromise is a smaller gear range (Rohloff being the obvious exception), ranging from a little smaller for the Shimano Alfine 11 down to "yes, there are two gears" for the back-pedal-shift 2 speed hubs. But in return you get extremely long life for the chain and cogs (10,000km or more for the chain, 20,000km+ for cogs) and a general low-fuss maintenance requirement. That also makes it practical to put a hub gear in places where derailleur gears could go but you wouldn't want them - under my load carrying quad, for instance, where the derailleur hung down between the rear wheels just waiting for a rock to break it off, and turning the thing over for maintenance is a pain.

Removing the rear wheel on a hub geared bike ranges from nigh on impossible (some of the Shimano hubs, and some dutch bikes have chain cases that are just irritating to work on) to almost trivial (a Rohloff with QR). The problem is the shifter cable - you have to detach it to remove the wheel. Good ones just unhook, poor ones you have to undo the adjuster barrel and re-adjust the gears on reassembly. Shimano are getting better, but Rohloff and Sturmey Archer have it down pat.

Servicing hubs is not often done these days. The manufacturers generally allow bike shops to swap out the internals for new, saving the hassle of building a new wheel, but that's about it. I had three Shimano Nexus 8 hubs fail at 5,000km intervals, and every time I just got replacement internals rather than the hub being repaired (the last time, of course, Shimano had stopped making the hub so I had to throw away the wheel). With Rohloff the same thing might happen, except after 150,000km or more... most people don't ride that far in a lifetime. Also, with Rohloff you change the oil every 5,000-10,000km, at a cost of half an hour of your time and about $20 for an oil change kit (or $10 for just the oil).

I usually run a Schwalbe Marathon Plus on the rear of my hub geared bikes, which trades a little extra rolling resistance for huge puncture resistance. It's part of the "my bike just works" philosophy. I'd rather reliably take an extra 30s to get to work than at random intervals be 5-10 minutes late and dirty due to a puncture (because you know that you'll only get punctures when you're in a hurry and it's raining).

what are the trade-offs between the internal gear hub and an external gear hub and derailleur?

The trade-offs are many and clearly in favor of derailleur gearing.
For example:

Some internally geared hubs have "freewheeling" positions between gears so if the cable is not adjusted, you can end up with no gear, causing you to fall if trying to pedal hard while expecting to be in gear
Repairing a flat is difficult. You need to remove the reaction arm and cable, and there is no mechanism to keep the chain in the correct position and tension it automatically. You also need to adjust the chain tension manually. In contrast, with derailleur gearing you just drop the wheel and put it back in after repair. No chain lube stained hands with derailleur gears. Typically there is no quick release either.
Like "modern" STI shifters, an internally geared hub is in general not worth it to repair. Changing a hub is difficult and requires wheelbuilding skills, unlike changing an STI shifter which is simpler.
Efficiency is lower than for derailleur gearing. For example, for 40000 km distance at 20 km/h (2000 hours), 2% lost power loses 0.667% speed (due to third-power-law effect of air resistance) and thus 13.3 hours.
They may not withstand as much torque as derailleur gears. For example, if I stand on the front pedal with my whole weight (114 kg), pull up from the rear pedal with 25kg (25 + 25 kg) and pull up from the handlebars with 30kg, I can generate 194 kg of force (1903 newtons). With 170 cm cranks it's 324 newton meters. With 16T/38T gearing it's 136 newton meters at the hub. This exceeds Rohloff spec of 106 newton meters at the hub.
Reliability is poor. There is no redundancy in the parts.
Repairability with field tools is nonexistent.
Hub gears are heavier.

Consider for example what could happen for my derailleur gears in a trip.

Chain tensioner or rear derailleur breaks: I reroute the chain and make my bike a single speed.
Front derailleur breaks: I use only one chainring
One chainring breaks: I use the other
One sprocket breaks: I use the other sprockets
Chain breaks: I make it shorter and avoid the forbidden gear combinations

There is no conceivable failure of a derailleur gear system that would need me to walk home apart from perhaps freewheel failure, and this failure mode affects internally geared hubs equally well.
Some supposed advantages and one true advantage:

Chain cases: nope. I have a chain case in my derailleur geared touring bike, so chain cases are not exclusive to hub gears.
Coaster brake compatibility: not useful. The coaster brake is an on-off brake and it's on the wrong wheel so it's of no value.
Stronger rear wheel due to more equal spoke tension: nope. Many modern bicycles are built with an asymmetric frame, resulting in more equal spoke tension even with derailleur gears. Besides, with proper wheelbuilding skills, good rims, good triple-butted spokes, 36-spoked hubs, etc, wheels with inequal spoke tension can be strong.
Fewer chain changes: true.

In my opinion, hub gears are valuable only if you absolutely hate chain changes. However, then you must hate chain lubrication as well and it's a problem affecting hub gears too.


Can you run a quick release skewer with a SON dynamo hub? Regular SON dynamo hubs come with a hex key skewer rather than a QR. That's not a big deal, but it's probably simpler for the other 2 riders on the household who are running these hubs to deal with a QR skewer, since it's easier for them to get a feel for a tight QR than for "8-10 Nm" on the hex key, especially using a crank brothers multitool by the side of the road.
I haven't seen any admonition not to use a QR, and I doubt they could get a QR cam to put more tension on the skewer than 10 Nm on the hex skewer would pull, but I'm not sure.
I'm wondering if the hex skewer is supposed to just be a security thing, since it requires a thief to have a 5mm hex head rather than just fingers. I'm not sure that's much in the way of security. I did get some pentagonal key skewers that would provide more security, since few people are carrying one of those around, but at present these bikes don't get out of anyone's sight.

Yes, they don't care, you can use any QR you want. I've used an early SON28 with the stock one, a Pitlock, an external cam light skewer, and various Shimano skewers, and a current SONdelux with the stock one and a Shimano QR. It doesn't matter.
I don't know the numbers but I believe internal cam skewers develop quite a bit more clamping force than bolt-down skewers, so in other words it's conceivable to make a hub that could care about this distinction. But Schmidt hubs don't.

Dynamo hubs provide a little bit of resistance. Lights on, it's 6 watts. You are probably pedaling the bicycle forwards at 100 watts. When braking, at 25 km/h (6.94 m/s), a 100kg rider + bike with 0.5 g braking force requires 3400 watts to brake.
So even though the SON dynamo hub is "braking" you all the time a bit, its braking power is about 0.18% of the power a real brake needs.
Go ahead and use a QR skewer. However, for this you need an axle that supports using QR skewers. I'm not sure if all SON models have the hollow QR axle.
However, internal gear hubs and hub brakes (apart from disc brake that has a caliper attached to the frame or fork) require some separate mechanism to apply the reaction torque to the frame or fork.


How can I mount a 25.4 mm seat-post on a frame that needs a 27.2 mm seat-post My bike has no rear suspension. So I thought of putting a suspension seat-post on it. Unfortunately the only suspension post available in my city is a 25.4 mm one. I have added some scrap metal to fix it for now. But it's still a little wobbly. What is the best way to do this ?

There are seatpost shims available for a few dollars. You should get them easily in your local shop or online.

I use an aluminum shim in one of my bikes with exactly the dimensions you need, it works flawlessly and looks very clean. I got it for about 3.50 € (5$).

I did cut the 27.2 old one and the new one fits perfect inside it


MTB front and rear shimano derailleur: which shifters for drop bars? I would like to convert flat bars of my MTB (old one: ATX 770 Giant, 7 speeds cassette with Deore DX derailleur and 3 chainrings crankset with probably DX as well) to drop bars, for touring purposes (I do not want STI shifters, and even less rapidfire system).

I am running into the following problem:
- Are Dura Ace downtube shifters compatible with the MTB derailleurs? If yes, how can I possibly set them up on the bike?
- OR would you think Deore XT thumb shifters somehow mounted on the drop bars are best (I guess it could be a bit tricky on a 40cm wide drop bar, with the necessary front light mount and handlebar bag mount)?
- OR do you think this is all silly and I should get a proper touring bike?

I think it's silly and you should get a touring bike. However, if you run Dura Ace with those derailleurs, the front derailleur will work like normal. For the rear derailleur, you'll have to give a little slack and instead of pulling it straight out to pinch, you have to bend the line to a 90 degree angle and then pinch. If you have more questions, check out Sheldon Brown's website. http://www.sheldonbrown.com/


Bicycle Components: What's The Real Difference? I am buying my first 'real' road bike soon and am comparing the Shimano Ultegra vs. the 105.

I have read through their websites and marketing literature. What does the semi-vast price difference do for a cyclist, who isn't riding the TDF?

There's a couple of things here.

First there are the physical properties of the groupsets. As you move up the groupsets, what you're buying into is essentially smoothness and lightness.

But for a recreational rider, you'd basically need the groupset to hit a certain minimum level of quality, and anything beyond that would be lost by the rider. And my guess is that for many of us the minimum level of quality is probably even lower than 105 - Tiagra and these days maybe even Sora.

In terms of reliability, you could also argue that there is an advantage to a lower-level groupset, because you're riding tried-and-tested technology rather than the "leading edge" technology used by the higher level groupsets (Dura Ace, Ultegra).

So why do shops sell the top-end groupsets? I think there is a big psychological aspect to this, and this is my second point.

On the one hand they are serving the interests of the top-end riders. But on the other hand, they are also catering for a huge bunch of riders (and I include myself in this category) who ride these groupsets simply because they can afford to do so.

As @mattnz says in his comment, it is all about vanity. It's exactly the same reason a guy will drive a Ferrari when he could get get from A to B just as quickly (assuming speed limits are observed) in a Ford.

Last, on a practical note, its worth saying that groupsets cost a lot less when bought as part of a bike, than they do when bought standalone. So if you're the type of rider who will say "if only I had a better bike I could smash my pb", you're better off by going for the superior groupset straight away - it will be cheaper in the long run than getting the lesser groupset and upgrading parts piecemeal.

However, upgrading piecemeal is possible (albeit as I say at a premium). Just note that the current range of Ultegra (6800) is 11-speed, whereas the current 105 (5700) is 10-speed. So to upgrade a 105 part to an Ultegra part, you'd need to look at older (10-speed) Ultegra ranges (6600 or 6700) or even 10-speed Dura Ace (7800). But certainly 6700 is still widely available.

You should try a few out to assess their shifting performance. Even better if you can do a blind test. Also consider researching the cost of new parts (eg: chains) and the ease of maintenance.

In my opinion weight is overrated and you can spend a lot of money to make a groupset 100g lighter.


Breaking spokes on adult tricycle My mother is 60+ years old and 200+ lbs.  She never learned to ride a bicycle, so she rides a Schwinn Town & Country adult tricycle.  She loves it and rides it everyday, 2-5 miles everyday.  The spokes on the rear right wheel keep breaking.  In the past year, since she's had the trike, she must have had 5-10 spokes replaced. The right wheel is also the "Drive" wheel, and the only wheel giving her problems.  Could it be a shoddy wheel? a bad wheel builder?

What could be done to fix this?  Stronger spokes? Replace the whole wheel for a new one?

I need help and I'm officially out of ideas...

Here is my 2c from over 10 years experience in a busy shop:

I am assuming that it is the spokes are breaking at the hub.
On a drive side wheel, that is where they always break.

There is a different rare condition, when the spoke nipples are breaking off at the rim.
Rims have two sets of holes, one set on the each side.
The spokes might be laced to the opposite side of the rim.
I have never seen this from any bike factory, but rather from amateur wheel builders.

When a wheel starts breaking spokes, the spokes are almost always to blame.
Aged galvanized spokes that are gray or rusty can have all kinds of microscopic corrosion fractures at the bend.  If the spokes are not corroded, or were made of stainless steel, it could even just be a bad batch of spokes.

Even if a bad wheel build was the original cause, the remaining spokes are damaged and will break with continued use.  Re-tensioning the old damaged spokes won't help.

I am surprised the bike shop replaced the spokes one at a time after the second time it came back.  If the wheel is breaking spokes, it will continue breaking spokes until the entire set of spokes is replaced.

There is one other possibility with three wheelers.
I have not seen a Schwinn three wheeler up close for 15 years or so, but in the old days they had chromed steel hubs, and those can sometimes be a problem.

If the steel hub has a sharp edge in the spoke hole, that is a stress riser.
The spokes break right where the spoke bend hits the sharp corner.  Aluminum hubs are softer and will deform a bit - no sharp edge, no stress riser, no breakage.

The drive wheel on a three wheeler uses a special hub, special made for that exact trike, so you are pretty much stuck with the hub it came with.

I have lightly chamfered the spoke holes in some problem steel hubs with a countersink bit to remove that sharp edge.  A dab of paint to avoid rust is useful too.

While the chamfering makes logical sense, and those wheels never came back, it is hard to tell if the chamfering did the trick, or if a set of new high quality stainless spokes was enough to cure the problem.

If the trike is only a year old, it should be a warranty repair to get a proper fix, not just one spoke at a time.  Either replace all the spokes with quality stainless spokes, or replace the wheel.  I would trust a new set of spokes more than a replacement wheel.  If the shop won't handle this under warranty for a one year old trike, then contact the shop owner, or go up to Schwinn corporate if you need to.

Hope this helps.

The woman is heavy. There is too much strain on the drive wheel spokes. An effective way to cure this is to reinforce the spokes by tightly wrapping good copper wire around the junction where the spokes cross in the x configuration. Then use flux and solder to make a permanent bond being careful to only use the minimum heat to avoid damaging the spokes. There are videos on YouTube. This works great.


How to carry skis on a bike? I don't have a car and think about biking to ski resorts. So the question is how to carry my XC skis on a bike. Have anyone tried doing this and what was the solution?

Thanks.

I have seen people trailer them, but for a local race here, many people go car free and strap them to the top tube extending back behind the seat, usually onto the rack.

Found many images using google image search for "carry skis on bike"
http://farm6.static.flickr.com/5132/5471607772_40dc377ed0_o.jpg

I would use bungees to secure them to the rear rack and let them stick out behind me.  As their weight is minimal, the bike's handling should change very little.


Can I use V brake levers for U brakes (side pull calipers)? I accidently bought a V brake set instead of U brake set (side pull calipers) for an old bike I'm fixing.
I really like the levers and would like to keep them.

These are the levers I've bought:
XLC BL-V05 Disc Brake Lever for V-Brake

Are V brake levers in general comaptible with U brakes?

I found this helpful site which explains the different types and compatibilities:

Mechanical bicycle brake compatibility

  Types of brake levers and calipers

  These are the brake lever types with their amount of cable pull per
  full lever travel (about 20 degree angle):

  V-brake (also known as Direct-pull, or linear-pull), 15 mm
  Cantilever (also known as center-pull and direct pull), 7 mm
  Old road, 7 mm
  New (SLR and Super SLR) road, 8 mm

  Here’s a list of mechanical caliper types with their ideal amount of
  lever cable pull:

  V-brake (also known as linear pull brakes), 15 mm
  Mini V-brake, 7 mm
  Cantilever (also known as center pull brakes), 7 mm
  Old  road calipers, 7 mm
  New road calipers (SLR and Super SLR), 8 mm
  MTB mechanical disc, 15 mm
  Road mechanical disc, 8 mm
  U-brake, 7 mm
  Roller brake, 7 mm

Conclusion

Regular V-Brake levers are not comaptible with U brake calipers

Really useful info about pull ratios and the answer is most certainly strictly correct, although from a practical perspective, I'll share my thoughts. A v brake lever will pull 15mm of cable whereas a road lever will pull through only 7 on 20' of deflection. So whilst you couldn't use a road lever on a v brake (you couldn't pull sufficient cable to engage the v brake far enough) , you could use a v brake lever on a normal road side pull to move the brake sufficiently to engage it on the rim .  The difference would be that the travel on the lever would be less (about half) to engage the brake calliper on the wheel rim but you would still be pulling the side pull brake through its ideal range.  It can't travel "too far" as the wheel rim is engaged to stop any excess travel (and you'll stop).
I've put v brake levers on an old 1970,s Dutch bike with side pull shimano brakes for my wife who didn't like dropped bars. Works fine - well in fact. I had thought that it would make the brakes twitchy or coversely reduce the stopping power as you might be losing some mechanical advantage, but in the set up I did (which was using super cheap levers off e bay) the brakes work well and the bite point on the brakes feels quite natural and solidly reassuring. The extra travel available seems to take up any flex (70,s calipers and £5 levers so they're probably both rubbish) in the system, meaning that the braking is actually very positive.
So, in summary, v brakes and side pull brake set ups are definitely different in terms of pull ratio, but in my experience, v brake levers with side pull callipers worked with some success.
If you were wanting to use road levers with v brakes, (based on the ratios quoted above) you'd have to swap out the v brake calliper for cantilevers, and put those on the v brake frame / fork posts to get sufficient calliper travel.  Some  "adventure / touring / gravel / cyclocross bikes seem run this set up as stock anyway.
Other people's experiences may be different to mine so take care with your own set up and thoroughly test the braking you end up with to your own satisfaction before using in circumstances where you might rely on the brakes for your own safety; I'm only sharing how it worked out for me.


Are Hövding helmets safer than regular helmets? I would like to know if these very expensive helmets (about 500€) are actually better than regular ones. I'm sceptical about the claim that they are three times safer: if they are so much safer, why do they not seem to be being used by professionals? I cannot find any serious studies supporting these claims, so am wondering whether they are in fact substantiated.

That's the inflatable "airbag" helmet.  It's main claim to fame is that it isn't really a helmet, but sits in a (dorky looking) collar around your neck until needed.

First off, I'm skeptical that the helmet could be tested to most bike helmet standards at all, since the test procedures would not be designed for such a helmet.  So it's pretty much impossible to say if it "meets standards", much less is better than others. For helmet testing info smf.org/standards/b/b90astd (thanks to @Ken Hiatt)

Secondly, the trigger mechanism can't rely (as a car airbag does) on waiting until impact to activate.  So it must trigger based on sudden movements of the head and upper body.  The reliability of this is questionable.  (Keep in mind that a substantial number of head injuries while cycling are due to simply falling off the bike -- the old "forgot to unclip" problem, eg.)

Third, given the iffy nature of the trigger mechanism, false triggering would seem likely, and having the helmet suddenly inflate in a critical situation could be extremely disorienting and lead to an accident that would not otherwise happen.

Bicycle helmets are all certified to the same standard, so I would be sceptical of claims that one is safer than another.  With bicycle helmets, a higher price usually gets you helmet that:

Weighs less
Has better vents to keep your head cooler
Is more stylish (i.e., "looks pro")

As for the Hovding helmet specifically, it looks like the main selling point is that it sits around your neck while you are not actively colliding with something.  Some people seem to think that conventional helmets look dorky and all helmets seem to give you "helmet hair" to one degree or another.  So, I would say that this is again a case where you are paying to get a helmet that gives you more of categories 2 and 3 above.


Thru Axle and Quick Release Fork/Frame Compatability? Without using manufacturer specific parts:

Can I use a wheel with a thru-axle hub on a standard quick release fork or frame dropouts (with an adapter)?
Can I use a wheel with a quick release hub on a thru-axle fork or frame dropouts (with an adapter)?

We may also want to consider that there are also different thru axle sizes, commonly 12mm, 15mm and 20mm.  I think the most common size of thru-axle currently is 15mm.

Simply for your two points:

For a front wheel you can buy or machine a part that will allow you to run a smaller axle on the front than the hub is equipped with. This an adapter to run a 15mm TA hub in 9mm drop outs.

The rear is more difficult as hub sizes get wider with larger diameter thru axles. You couldn't make a 12x142 thru axle hub fit in a 10x135 QR dropout even if you shimmed the space at the end as the chain line would be off.

In terms of frame/ fork design, the design form for through axles offers no backwards compatibility with QR drop out design. I haven't seen and can find no evidence online of an adapter that allows you to run a 9mm hub in 15mm TA drop outs. That being said it could be possible to engineer something that created the required tension to hold the hub in place, but I wouldn't trust a home made solution.

I've never seem an adapter for either of these situations. I doubt one would fit.

That said, a lot of manufacturers use the same hub body on their through axle and QR wheels and are more than happy to sell you the bits that are different.

I had this problem when I got a pretty good deal on some wheels with a 15mm front hub. In the end, after a month or two of looking, I found somewhere with a non tapered 15mm fork in stock and bought that over rebuilding the hub.

The best way, is to choose wheels that fit out of the box!

PS I found this adapter for a 15mm QR on a roof rack, not sure I'd like to ride it...