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Old 01-23-09, 10:19 AM   #1
vik 
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More powerful brakes?

Braking is a topic near and dear to the heart of cycle tourists for obvious reasons. One thing I read frequently is people claiming one type or brand of brake is more powerful than another.

My question is this:

If you have two types/brands of brakes on a bike and both brakes will readily allow a normal rider [so not require excessive force at the brake lever] to lift the back wheel [in the case of the front brake] or skid the back wheel [in the case of the rear brake] is there any point in trying to suggest one brake is more powerful than another? Isn't the practical limit of a brake's power the endo or skid [as applicable]? So aren't all brakes that can make these two things happen on a given bike equally powerful for all practical purposes?

I realize there are other differences in brake systems such as modulation, heat dissipation, maintenance, etc..., but I'm only interested in the concept of one brake being more powerful than another.
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Old 01-23-09, 11:10 AM   #2
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Braking is a topic near and dear to the heart of cycle tourists for obvious reasons. One thing I read frequently is people claiming one type or brand of brake is more powerful than another.
this is utter nonsense. Branding has nothign to do with it, it is purely and aspect of brake design. One of the reason I love
the inexpensive tektro brakes that copy the proven designs. If you want to spring for pauls or other, be my guest, but aside from aesthetics the performance is a function of basic physics - force, lever-arm, etc.

My question is this:

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If you have two types/brands of brakes on a bike and both brakes will readily allow a normal rider [so not require excessive force at the brake lever] to lift the back wheel [in the case of the front brake] or skid the back wheel [in the case of the rear brake] is there any point in trying to suggest one brake is more powerful than another? Isn't the practical limit of a brake's power the endo or skid [as applicable]? So aren't all brakes that can make these two things happen on a given bike equally powerful for all practical purposes?
Assuming the same load, grade of road, speed etc, I agree. locking the wheel into a skid is the limit of braking power. This is undeniable fact. I guess one could pick nits about how much hand force is required to acheive that upper limit, the stronger brake requiring less hand clamping force.

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I realize there are other differences in brake systems such as modulation, heat dissipation, maintenance, etc..., but I'm only interested in the concept of one brake being more powerful than another.
those issues should not be glossed over so quickly. In my opinion, this is the primary difference between braking systems. Disk brakes are not 'stronger' but (can) have more modulation than any other type of brake out there. this issue has been obfuscated by the uninformed to equivalence with strength... but there is a reason that disks were first adopted by technical omountain bikers. 1) they care less about the weight of the design, and more importantly 2) modulation is of UTMOST importance on dirt/gravel/offcamber singletrack surfaces. locking brakes in such a terrain is useless, and even dangerous, while controlling wheel speed without lockup is critical to performance. this is to say that the most powerful brakes are not what is desired for Mtn biking, but rather the most modular... the brakes with the widest range of effect before reaching lockup.

it can be questioned whether the road cyclist has a need for such modulation, given the difference in surface. I dont know, my cantilevers work fine, as do my dual pivot calipers... i dont see the need for disks in my normal use. but that said, there are other issues that might make a difference: wet weather performance, rim wear, pad use etc. these might suggest one design over another.

I used to ride downhill bikes a lot though, and both of my cousins are sponsored downhill riders/racers and course designers in Switzerland. They would never consider using anything but disks because they value modulation more than any other factor including strength.
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Old 01-23-09, 11:11 AM   #3
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I tend to agree, except I'll add that the amount of force needed to lock the brakes --that is, how hard and how far you have to move the lever-- is an important factor. This is especially important for a rider with small and relatively weak hands, such as my 9YO daughter. It seems she needs especially strong brakes on her bike despite the fact that she weighs very little.
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Old 01-23-09, 11:55 AM   #4
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I'd also include material type and quality (which is where the branding generalization might come in sometimes).

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but aside from aesthetics the performance is a function of basic physics - force, lever-arm, etc.
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Old 01-23-09, 03:09 PM   #5
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I tend to agree, except I'll add that the amount of force needed to lock the brakes --that is, how hard and how far you have to move the lever-- is an important factor. This is especially important for a rider with small and relatively weak hands, such as my 9YO daughter. It seems she needs especially strong brakes on her bike despite the fact that she weighs very little.
fair point. For the record, there are a number of "short reach" levers that are out there which might be of use to her - like the excellent small version of the tektro levers. pretty cheap too, about 25 bucks and verrry nice. I use these and my little grabbers are happy.
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Old 01-23-09, 03:53 PM   #6
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You also have to consider that depending on your position on the bike, you don't always have the leverage available to pull the brake levers as hard as you can at other times. There's one particularly steep hill with a stop sign at the bottom here in town. If the riders on race bikes lean all the way down to really get a good grip on those levers, they'll go a** over tea kettle. Most of them brake from their towers which takes away most of the leverage and prevents them from stopping short. When I'm on my cross bike with its cantis set up real strong, I have no problem stopping short.
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Old 01-23-09, 06:21 PM   #7
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My experience isn't as technically erudite, but I understand the idea of having an entirely different braking characteristic on a mountain bike going hell-bent down a 'chute. Most of the brakes I've used on all sorts of bikes work pretty well, with a couple of exceptions. IMO, it's mostly the brake pad that determines my stopping effort. Those Salmon Kool-Stops can really clamp me down - all 250lbs of me+baggage. Conversely, my '06 Specialized Sequioa Elite, with 105 levers, are almost dangerous on a very fast descent. At least I know that the loud hissing sound will scare off any deer or small children at the bottom. They'll hear that a mile away. I'll be installing some chewed bubble gum on that this spring.
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Old 01-23-09, 07:40 PM   #8
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Excellent discussion. Some new ground on a stale subject.
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Old 01-23-09, 08:21 PM   #9
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I find any ;ol brake can lock up the back tire. Which is exactly what you don't want to do anyway.
To get topped you need front brake. In my experience some are much better than others. On my road bike I got a front Dura Ace caliper. It's stiff enough that I can brake effectively from the hoods. Other calipers didn't work nearly so well.
If I were touring a loaded bike I'd definitely want discs or cantilevers.

BTW, an endo would be the result of poor weight transfer control, not too much braking, imho.
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Old 01-24-09, 11:45 AM   #10
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I'd agree with all the posts above....setting up the brake is most of the battle. I think many riders tend to think *stiff* feeling brakes are more powerful brakes. I don't believe this is the case at all-- in fact, the mechanical advantage grows higher as the levers near the handle bar. So a bike set up with *mushy* brakes often is better on a long descent (braking from the drops, using your big finger at the very tip of the lever) than one with *snappy* or *stiffer* brakes (the kind a lot of weekend racers use)
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Old 01-24-09, 12:43 PM   #11
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in fact, the mechanical advantage grows higher as the levers near the handle bar.
I set my cantilevers up sort of 'mushy' too, but is the above statement true with v brakes? I thought that this ceased to be true with the linear pull design...
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Old 01-24-09, 08:55 PM   #12
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I guess we're not going to see ABS braking systems on bikes any time soon so maybe the question (for the rear brake anyway) is which type of brake best allows you to achieve a similar result (yes, I know aquaplaning is not the issue but a skid is similar). I don't know the answer to this question but suspect that the superior modulation provided by many disk brakes means they would come closest to an ABS result. Certainly, the rear disk brakes on my bike seem to provide a much smoother application of stopping power and are less 'grabby' than most rim brakes I've used.
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Old 01-24-09, 09:52 PM   #13
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I set my cantilevers up sort of 'mushy' too, but is the above statement true with v brakes? I thought that this ceased to be true with the linear pull design...
Yes, it's still true. It's not the brakes, but the human hand fitting the levers. It's easier to grip a broom handle than a fence post. Most of the time there's a brake issue on a bike, it's not the actual brake, but the housing, cable, cable stop/hanger, brake pads or levers.

V-brakes, BTW, take more cable pull to work. This gives them better modulation than catilevers and makes them way easier to set up.
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Old 01-25-09, 10:15 AM   #14
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The ability to modulate the brakes is certainly almost always overlooked. With racing cyclists this is all important in that riding in a group they need to use a fine degree of modulation in braking in order to respond to any change. Overall strength of braking would seem to be a bit less important and is more easily obtained.
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Old 01-25-09, 10:30 AM   #15
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The critical part of adjusting cantis is matching the length of the straddle cable with the design of the brake. Keep the straddle wire about 90 degrees from the arms. Arms with 45 degree (relative to the wheel) set need a lower straddle wire settup than the 90 degree arms. Tektro has both designs. The old 90 degree canti arms were the original design from Shimano and now seem to be making a comeback. If the pull on the Canti levers seems mushy then check the straddle cable length. A little adjustment can make a great difference in feel.
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