cynergy

Hi All,

I have an older Trek 800 mountain bike that currently has direct pull cantilever brakes on them. They work OK, but I'm considering replacing them with V Brakes.

What are the advanatages of the V brakes over traditional cantilever brakes? Do they provide greater leverage over the traditional kind? Also, are they easier to adjust/center?

Thanks in advance.

Retro Grouch 

Like Kleenex, to be a V-brake it has to be Shimano. Linear-pull is the collective name for such long arm, side pull cantilever brakes.

I'm not an engineer so I can't say if there's a leverage or power advantage to linear pull brakes. I kind of take the approach that enough brakeing power is enough and traditional center pull cantilever brakes have plenty of stopping power to suit me.

I think that the better quality linear pull brakes, like Shimano and Avid, are a lot easier to set up and center than the older cantilever brakes but the newer designed canty's clearly are cutting into that advantage.

well biked

+1
FWIW, I've done a lot of off roading with both types (traditional canti's, linear pulls), and I do think there's an advantage with the braking performance of linear pulls. Not a huge advantage, but they do seem stronger to me. If set up with servo-wave levers, you can get very stong braking with excellent modulation as well.

Also from the FWIW department, linear pulls have more mechanical advantage than other rim brakes, but the levers you use with them have less mechanical advantage than conventional levers-

edzo

v-brakes (actual shimano) have a pivot that keeps the pads parallel as they wear.

the advantage is less brake maintenance while your pads wear out.

otherwise, no advantage over v-brake copies.

---

CdCf

Not all of them...

Retro Grouch 

Since the rim is what is causing the pads to wear, why wouldn't the pads wear squarely relative to the rim?

well biked

I've got "parallel push" XT v-brakes from a few years ago, Shimano touted them at that time as having "15% more braking power" than other linear pulls. What that means in the real world, or how they arrived at that figure, I have no idea. There was no mention of pad wear, maintenance advantage, etc. that I remember. But combined with the XT servo-wave brake levers, they are indeed excellent brakes, mostly because they have excellent modulation for rim brakes.

Also, because the OP's terminology is a little off regarding "direct pull cantilevers" in the opening paragraph (this would be linear pull brakes), I'm not completely sure we're all talking about the same thing. I'm assuming the OP wants to compare traditional canti's vs. linear pulls, not V-brakes vs. other linear pulls, but I could be wrong-

kevbo

One advantage I seldom see mentioned for the newer style brakes is the increased cable travel. Because the travel is doubled, and the force halved, the effect of cable stretch at the hand is reduced by 75%. Now, to be sure, things had evolved to where cable stretch really wasn't a problem for traditional brakes on most bikes, but there was a really noticeable improvement to the rear brake when I went from cantis to the direct pull brakes on our tandem. (due to the long cable run, stretch tends to be much more of a problem on long bikes) Note that use of travel-agent devices located at the caliper end of the cable run negates this advantage. On our tandem I use the in-line travel agent located at the front of the bike...levers with the correct ratio would be a better solution, but that would require seperate shifters on our drop bars.

HillRider

I believe the intent of the linkage that made the pads travel in a straight path is that, without it, the pads tend to hit lower and lower on the rim as they wear and the arc of their travel gets longer. Eventually, unless you keep the the clearance adjusted, they can "submarine" the rim and hit the spokes.

Their downside was wear at the various pivot points and a tendency to vibrate and squeal due to lack of rigidity.

well biked

That's not what Shimano advertised as the advantage, they claimed the parallel push design made the brakes more "powerful" (15%). Again, I have no idea how that could be, but that's what they claimed at the time they first introduced them. For a long time, the feature was only available at the XT and XTR level. FWIW, my XT parallel push brakes that are several years old appear to have a more complicated design than the current Shimano v-brakes that are listed as having the "parallel" feature-

Mr. Fly

Linear pull brakes offer one big thing that cantilever brakes don't – stupid-proof setup.

With cantilever brakes, especially if a Shimano straddle cable isn't used, setting up is very flexible (i.e. wide range of mechanical advantage vs. clearance) but involved. If the setup isn't exact, the brake will often feel weak or spongy, or both! However, with good setup, the brake will perform no worse than any linear pull brake while still offering the user flexibility. Even with an experienced wrench, proper canti setup is a 5-minute per end job.

With linear pull brakes, setup is a 30-second affair – line up the pads, clinch down, adjust for pad clearance, center if necessary and it's done.

When comparing cantis to linear pulls, please ensure that 1. the brake pads are the same, and 2. the mechanical advantage adjustment for the cantis matches the linear pulls. Otherwise it's not an apples-to-apples comparison.

Finally, see Sheldon Brown's website for detailed instructions on how to properly set up a cantilever brake, and why that is so.

Sheldon Brown

Leverage, a.k.a. "mechanical advantage" has nothing to do with the type of mechanism, any type of brake can be designed to provide any desired leverage. Usable leverage is determined by how much clearance you need to provide to accommodate out-of-true wheels, and by the length of typical human fingers.

Direct-pull ("V type") cantilevers move the cable twice as far, while pulling on it half as hard. This reduces the problems introduced by cable stretch and cable friction by approximately half.

These also provide basically constant mechanical advantage (leverage) through the brake/lever travel, which is generally a Good Thing. Traditional center-pull cantilevers have M.A. that varies during the stroke, generally becoming less as the brake shoes move closer to the rim. That's undesirable.

Traditional cantilevers require fairly careful setup, and not everybody understands how to set them up properly. Most of them that are in current service are not set up well.

Direct-pull cantis are comparatively idiot-proof as far as setup is concerned.

See also: https://sheldonbrown.com/cantilever-adjustment.html

It's tough to make a drop bar lever that works well with direct-pull cantis, so generally I recommend traditional centerpulls for drop bar applications.

However, if your bike has upright handlebars, direct-pull ("v type") cantis are the best choice.

Sheldon "To V Or Not To V" Brown

Fibber

On two occasions I purchased reasonable quality used bikes for my kids that had cantilever brakes. As has already been mentioned, you need to have at least some mechanical aptitude to set them up right. There are several degrees of freedom in the pad clamping and cable adjustment that can take them from excellent to downright scary.

After some fussing with the most recent acquisition, a Trek Mountain Lion, I decided to convert the system to linear pulls. I grabbed a suitable donor bike on Town Junk Day, and stripped off the needed hardware.

In theory, you need to match up handlebar levers with the style of brake. The mechanical advantage or cable take-up rate is different, and it is generally not recommended that cantilever levers be used with linear pulls. The results have been labeled 'too powerful' or 'touchy'. I did some quick measurements and decided to proceed with adding the wheel components without changing the handlebar levers.

I let my older daughter try it out, and she was quite surprised by the results. Her comment: "wow, I didn't expect the brakes to be so powerful!!!" The result is a system that does not take a lot of squeeze to produce a lot of braking force. Is this a good thing? For you as a mountain biker, maybe not! You may find them too hard to modulate. For a little kid, this is a great breakthrough, as most children find it very difficult to get their hands around levers and squeeze hard enough to brake effectively. Go to a big box store and put your hands on the kind of bikes most parents buy their kids. I'm not sure how some young riders can do it, or how manufactures can put out these products in all good conscious.

JanMM

My experience with maintaining my and my family's bikes goes back two decades with canti's and 1 decade with V-brakes. I find V-brakes much, much, much easier to set up and adjust. Both types work well in my world. (Shimano lawyers would support reserving the name for their product, but most everybody else would agree that a V-brake is a V-brake, no matter who makes it.)

HillRider

I know I read the explanation about keeping the pads in the the same place relative to the rim as they wore as being an advantage of the parallel-push design. It may have been an evaluator's comment rather than Shimano's claimed advantage. I agree that I also don't see how it could make the braking more powerful.

Sheldon Brown

The advantage of the "Parallel Push" is the _direction_ the pads move in.

Simple cantilevers, either cable style, move in a circular arc centered on the frame/fork boss.

For bikes with skinny rims and fat tires, this creates difficulty because the brake shoe can rub on the overhanging, bulging tire's sidewall when it's in the rest position. This is especially probematical if the brake bosses are widely spaced. The brake shoes move downward as they move inward, to a greater or lesser extent.

If you lower the brake shoe to safely clear the tire, it risks "diving" under the rim as the brake shoes wear.

The "Parallel Push" linkage causes the brake shoes to be traveling in a roughly horizontal direction in their normal range of motion. (Actually, it's still a circular arc, but it's centered on the lower, inboard pivot of the parallelogram.)

Sheldon "Geometry" Brown

HillRider

I believe that is pretty much what I said I had read was the chief advantage of the parallel-push configuration.

operator

Does anyone actually have a picture of this mechanism? I'm curious.

well biked

What you all are saying makes sense, but I'm telling you, Shimano touted the parallel push design as having 15% more braking power than other linear pull brakes. Probably mostly marketing BS, but I promise I'm not making it up-

well biked

Here's some of the newer XTR v-brakes with the parallel push feature. Notice the little pivot linkage that creates the parallel path of the brake pads:
https://www.performancebike.com/shop/...tegory_ID=5222

Fibber

Oh, that's cool! A parallelogram to counter the arc motion. I had not seen that feature before. If properly set up, this could indeed result in a greater (better aligned) pad face to rim contact area right out of the box, and throughout the entire pattern of wear.

Anyone who has ever set up automotive drum brakes could see the advantage of this design.

BigBlueToe

Aren't linear-pull a little easier to, well, pull? Santa Rita Road, a road near here, climbs to the top of a mountain ridge. It's a nice climb that I've done many times. On my old Stumpjumper with cantilevers, coming back down was painful on my hands. It's all downhill and you spend much of your time on the brakes to keep from going too fast around gravelly, blind corners. My hands used to ache by the time I got to the bottom.

I rode up it this weekend on my new (to me) Rockhopper with linear-pull brakes. I experienced none of the pain or aching on the way down. This was just a one-time sample, but I was happy with the performance of the linear-pulls compared to my old cantis.

CdCf

What do you feel is wrong with the Dia-Compe 287-V levers?
I have them on two of my three bikes, with three of them set up with regular V-brakes and one (the front of my singlespeed) set up with an Avid BB7 disc brake. I've never had a problem with them. Setup is very quick and in my opinion actually easier than levers for straight bars.

Well, I guess they're not so hot if you want integrated shifting mechanisms...

moxfyre

Much easier to adjust and center! The mechanical advantage doesn't depend much on the spacing or angle of the arms, so a lot more tolerance. Also, the pads are threaded, making them a lot less finicky to get in place than traditional smooth-post canti pads.

Also, their mechanical advantage is 1.5-2x that of traditional cantis, meaning that when you pull the lever, the brake pads move twice as far (but with half the force). Which gives a general feeling of increased stopping power if correctly set up. The downside is that you have to use different levers, unless you already have the kind that can be switched between standard and v-brake cantis.

Overall, I would say good cantis can be set up to be just as strong or nearly as strong brakes as V-brakes... but it's a lot more annoying of a job. V-brakes are a good upgrade, and don't cost much. I've had good luck with the cheap Performance V-brakes and levers, which look nice and perform well.