Differences between canti, V and U brake.
 

I know that it's a pretty generic question. Part of the answer concerns the U brake. I pretty much know that the U brakes are for road only applications. But what about the Cantilevered and the V (linear pull) brakes?

Here's why I ask.

I have a Shogun Trail Braker frame that I've stripped and am assembling into a tourer / commuter.

I have both a set of V brakes and Canti's but can't decide which way to go. I thought that the Cantis were stronger and acted more positively stopped heavier bike easier than other types of brakes. Is this true?

I've already test fit both sets and either will work on this frame. I just need some input to know which way to go.

V-brakes require either MTB style brake levers, direct pull aero levers or travelmates to work on drop bars.
Canti brakes work with regular drop bar aero levers without any need for special parts.

wide cantis (i.e. tektro CR720) and regular V-brakes will work similarly with their respective levers.

So, if I understand correctly, there is no clear advantage in the performance department. Just more of an issue as to what levers would be used in conjunction with what handle bar set up.

If I want to go with drops or trekking bars, then canti's and either aeros or non aeros would work.

If going the V Brake route, I'd be restricted to MTB levers and upright type bars.

To use the V brakes, I'd need a "travel agent" to get the correct travel ratio, correct?

Right, correctly set up a reasonably skilled(and able-bodied) rider will bring a bike to stop equally well with either type.
The most significant difference is between smooth post cantis and pretty much everything else, as the smooth post cantis can be quite bothersome to set up. There's one bolt responsible for the alignment of the pad in every direction.
A secondary consideration is clearance, V-brakes offers the biggest clearance if you want to run (wide)fenders, which can be an issue with caliper brakes and cantis.

No, there are two interfaces that has to match:
1) brake lever to bar diameter
2) brake lever to brake

For those who look there are off diameter bars out there, as well as shims and the renowned travel agent.

Trekking (AKA butterfly bars) usually take MTB-standard components. And there you have brake levers like the Avid Speed dial and Shimanos servo-wave(sp?) which allows you to choose between V-brake pull and Canti pull by adjusting the anchor point of the cable. I suppose Aero(drop) bar levers could be shimmed to fit, or you could go for a moustache bar instead and have instant fit.
There's also a set of aero brakes with enough pull to activate v-brake levers, a tektro-something I believe.

No, you can either run the v-brakes via a travel agent. It works fine although they're a bit sensitive to crud. Or there's also a set of aero brakes with enough pull to activate v-brake levers, a tektro-something I believe.

Avid also makes a set of short v-brakes which supposedly are compatible with ordinary drop bar brake levers.

Firstly I know nothing about u-brakes so I'm just going to compare v-brakes to cantilever brakes.

V-brakes ARE stronger brakes than cantilever brakes. Cantilevers came first and have the advantage of using standard cable pull so they can be used with regular drop bar levers and STI levers. V-brakes are a later development and they are stronger but need different levers from cantilever brakes for best performance although you CAN get drop bar levers for v-brakes. I'm currently using a set of Dia-compe levers on a drop bar/v-brake setup and they work well. Tektro also make a set of levers for v-brakes and drop bars. These are brake levers only so gear shifting is separate. I'm using bar end levers.

Now some argue that cantilevers can be just as good but I disagree. Yes you can setup cantilever brakes if you know what you are doing and have the patience to be good enough for someone with strong hands but thats not the same as the power available from v-brakes. I have poor hand strength and I can easily lock up a front v-brake for better or worse.

A cantilever brake has the advantage of you being able to use it with STI levers but a v-brake with the right lever will outperform it.

Anthony

U brakes are similar to single pivot road calipers

I believe there is a big difference between U brakes and cantis/v-brakes.
From Sheldon Brown
"A U-brake uses studs that are above the rim, rather than below the it, as with conventional cantilevers."
From here.
http://www.sheldonbrown.com/gloss_u-v.html

No. U-brakes were a failed attempt at a 'better' brake back in the mid 90s. They mounted on studs similarly to cantilever or V-brake studs but they were of a different diameter and a different placement than either and thus can't be replaced by either. They wrapped around the wheel like center pull brakes and collected crap about as well:rolleyes: Often they were mounted on the below the chainstay where they collected mud.

U-brake:

http://www.geocities.com/cegrover/ArrivalUBrake1.JPG

Ugly U-brake:eek:

http://www.zealbmx.com/Product%20Sho...0U%20brake.jpg

In what way?

You are correct in everything but the above statement. Speed Dials and Servo-wave may have adjustments for lever feel, i.e. how much force is needed to apply the brakes, but they aren't adjustable for the different cable throw needed between linear brakes and cantilevers.

I think the confusion is coming from the look of a traditional road caliper and what was designated as a 'U-brake' back in the dark days of the '90s. Road calipers do have a U shape but they were never called U-brakes.

Late '80's, to be more accurate.

D'oh. You're right. I held off purchasing a new mountain bike after my RidgeRunner bit the dust because of U-brakes.

My opinion, for what it's worth, is that V-brakes are better than cantilevers. Here's what it's based on:

There's a local dirt road that goes up to the top of a small pass. It's uphill all the way - a nice, gentle climb, and makes for an excellent day's ride with a nice view at the top. Since it's a steady grade up, that means it's all downhill on the return - almost nothing but coasting. However, since there are many tight, blind, gravel corners, you have to keep your speed down, which means tons of braking.

When I did it on my old Stumpjumper with cantilevers, all that braking was painful. I sometimes had to stop to give my hands a rest from too much squeezing. When I got my newer Rockhopper with V-brakes, this was no longer a problem. The amount of effort was much lower and there was no aching.

Perhaps that's not the most scientific study, but it's good enough for me. I have cantis on my LHT. I'm thinking the next upgrade might be V-brakes.

Same difference, all the brake levers can do is to trade force for travel - or the other way around. Adjustable for force is just another way of saying adjustable for travel.

Basic numbers:

The average distance between brake lever pivot point and brake cable anchor is 28 mm for a canti/caliper compatible brake lever and 35 mm for a v-brake lever.

I can't really vouch for the servo-wave as I haven't one available, but the Avid Speed Dial is definitely adjustable between 28-35 mm, which would make it equally compatible with both v-brakes and canti brakes.

V-Brakes provide the bigest bang for the buck - so to speak. They give you the greatest force for the least lever pressure of the three. If I were looking at loaded touring, I would strongly suggest the Avid Single Digit 7 and Speed Dial levers. I have a set of these as well as Avid BB7 Discs. These are the next best thing to the discs. They are often sold as an upgrade kit liike this: http://www.blueskycycling.com/produc...-Brake-Kit.htm

This topic arises again and again, do we really need to rehash it? Give it about a day until the Canti people come out in force, and then three pages of diatribes and anecdotal experiences later no one is convinced of anything.

It's personal preference, nothing more. Canti's take more effort to set up, but are much easier to customize to ones personal needs.
V-brakes work well from the get go, but heaven help you if you need to tweak them, all you can manage is tightness. This is mainly a problem for running them with fenders, but mud clearance can also be an issue.

The Speed Dial doesn't change the location of the cable anchor point. It only changes the location of the pivot point. Below is a cut away of one of the levers

http://www.nexternal.com/icycles/images/ultprolever.jpg

When I've played with the Speed Dial on these brake levers, the cable anchor point has not moved. I haven't had to adjust the brake pad adjustment which I would expect if the anchor point was moved 7mm (0.25") That's a lot of cable adjustment and would be very noticeable.

You might be able to change the anchor point with the lever reach adjustment but even there 7mm is a whole lot of adjustment...much more then normal. I've adjusted both the pivot and the reach for my wife's tiny hands but neither changes the anchor point that much.

With brake lever pivot point I'm referring to the part that the brake lever hinges on/around. I'm quite curious to how you manage to adjust that one short of doing some serious machining on the lever and its housing. You must be thinking about some other part of the assembly.

Look at the pic, The lever pivots around the stubby axle just below and to the right of the return spring. Turning the adjustment screw will effectively change the amount of leverage and stroke that the brake lever has.
The fact that there is an oblong bit between where the cable hooks on and where the adjustment is carried out doesn't change a thing, it's just acting as a linkage and doesn't influence the basic issue of the way the leverage changes as the adjustment is turned up or down.

It would, if it was in line with the cable, but as it is it's pretty much perpendicular to the cable, so the immediate effect on cable length is marginal.

Here, I've drawn in the effective lever length. And that one does change when you turn the adjustment screw, and the reach bottoms out at around 28 mm and tops out above 35 mm.

Unless you have a compelling reason to use cantis (you would know if you did) go with vees.

Turning the Speed Dial screw does change the leverage but it doesn't move the cable anchor point. All the screw does is move the end of the cable anchor up and down in a plane. The end of the anchor that is attached to the screw has a pivot in it so that moving it up or down changes the pivot point of the whole system. The end of the cable stays in the same spot and no extra cable length is added or subtracted.

Your picture illustrates what I've been saying

http://www.bikeforums.net/attachment...0&d=1232572359

Moving the end of the anchor arm up or down does not change the relative position of the anchor point. In order to get more or less cable pull, you'd have to move the anchor point relative to the pivot point. That just doesn't happen in the Speed Dial (or Servo Wave) levers.

Frankly, you are the first person I've ever run across who says that the Speed Dial or Servo-Wave feature can be used in the way you are describing.

I'd agree on that point. Cantilevers are useful on road bike/cross bikes/touring bikes but for a flat bar application, just go with the linear brake.