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I bought a used bicycle that has v-brakes installed (I'm not sure they were there initially; maybe the previous owner replaced the brakes).

Even after replacing the pads, I have a problem with them – no matter how close to the rim I leave them, the braking power always seems so-so. Besides the obvious safety implications, these brakes are also a maintenance nightmare. The wheel needs to be very true and I need to frequently readjust the brakes so that they are centered and do not touch the rim when not engaged.

I find this strange because I have another bicycle with v-brakes and, with a much larger clearance between the pads and the rim, I still cannot pull the lever down completely.

I measured with a caliper how much the arm link shortened when the lever is fully depressed and it was 12.7 mm. On the other bicycle, I measured some extra 5 mm (17.6 mm) for the maximum force I could apply to the levers.

I've also noticed that the brake arm is shorter and the distance between the mount points and the brake pads is larger on the good bike (I don't recall exactly, but by 3-5 mm). A larger arm and shorter distance between the fixed mount point and the pads aggravates the problem, I should think.

Do you think there may be some mismatch between the type of brakes the levers were designed for and the ones I have?

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    Levers intended for cantilever brakes pull less cable but with more mechanical advantage (i.e. harder). That would explain why you have to have the pads very close to the rim, but not the poor performance. The brake action would feel very abrupt and not easily modulated. – Argenti Apparatus Mar 11 '18 at 1:28
  • @ArgentiApparatus if I leave them very close, depress the lever with a foot, grab the fork with one hand I try to move the wheel with the other I can barely move the wheel. But once I'm on the road I notice the braking power is insufficient. And should I even be able to completely depress the lever? – Artefacto Mar 11 '18 at 1:48
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    There are actually 2 levers providing mechanical advantage. One in the brake lever on the handlebar and one at the caliper. The one in the brake lever can either pull less cable length but with more force, or more cable length with less force. Once the pads touch the the rim How hard the caliper squeezes the rim is not related to the distance the cable moves, but how much force the cable exerts. – Argenti Apparatus Mar 11 '18 at 3:32
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    Do the brake levers have any kind of marking or model number on them? We might be able to check whether they're actually v brake levers – Chris H Mar 11 '18 at 7:10
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    @Criggie I've added the pictures as I requested. I also found a label, on the underside, that I hadn't noticed before. – Artefacto Mar 11 '18 at 11:46
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Now that pictures are posted we can confirm that you do have levers intended for cantilever brakes.

The levers are from the Alivio MC11 groupset which was offered in 1994. This must have had cantilever brakes as the first V-Brake equipped groupset was the XTR M950 which appeared 1996.

V-brake levers are cheap and easy to install but you have a problem because you have integrated shift and brake lever units. However there are adapters available to convert short pull levers to long pull calipers. An example is Problem Solvers Travel Agent.

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    Suggest that you add something about "the best fix here is to replace your levers with V brake compatible levers" cos its the cheapest and easiest solution. The travel agent adds complexity to a system that should remain as simple as possible. – Criggie Mar 11 '18 at 19:15
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    #Criggie Looks like the OP has integrated lever/shifters so replacing brake levers is complicated by having to find separate 7 speed triple thumb shifters as well. Given that fact I thought the Travel Agent would be the simplest solution but understand it has its own complications including need to replace cable with a longer one (but OP should probably replace cables and housings anyway). – Argenti Apparatus Mar 11 '18 at 19:36
  • You don't think replacing the brakes with cantilever brakes is a good option? – Artefacto Mar 11 '18 at 20:04
  • Cantilever brakes cost more than travel agents and need cable hangers if your frame and fork/stem don't have them left from previous brakes. – ojs Mar 11 '18 at 20:18
  • Getting a set of cantis and hangers could be possible for not much money. Try EBay or a local bike cooperative that keeps a stock of older parts to keep older bikes going. Bike obviously has mount points for hangers because it must have had them fitted originally. – Argenti Apparatus Mar 11 '18 at 20:23
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It sounds very much like you have levers intended for cantilever brakes in combination with V-brakes. The cantilever levers pull the cable a shorter distance with greater force. Because the V-brake requires more cable movement, the levers touch the handlebar before you can pull them enough. The difference in brake mounting points adds to the problem but is not the root cause.

There isn't much information about your levers on the Internet, but they look like they were intended for cantilever brakes. A V-brake lever would have the pivot next to handlebar, but here the pivot is half way to the lever.

EDIT: Another answer has information about the manufacturing year of these levers, and these are indeed from time before V-brakes were introduced.

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Two possibilities are that you have the original brakes and levers (ie., your system is as it was designed to be) but that either:

  1. Your pads are glazed over or hardened. Try replacing your pads.

  2. Your brake cables are “stretched” - as cables get older, they become "stretchy" and this reduces braking force. New cable inners and outers are quite inexpensive and will rejuvenate your brakes.

Both of these are inexpensive repairs. The pad replacement you can do yourself. The cable replacement you can do yourself if you have your shop cut the outers to the right length (or if you get your own bicycle brake outer cable cutters).

  • 1) I have already replaced the pads 2) You mean the cables get elastic? 3) is it normal to be able to bottom out the levers (assuming the pads are already < 1 mm away from the wheels)? – Artefacto Mar 11 '18 at 2:20
  • Being able to bottom out the levers should definitely not be possible. Yes steel cables can stretch, but deformation and movement of the housing contributes as well. – Argenti Apparatus Mar 11 '18 at 3:39
  • The cables aren't really phsically "stretching" - instead what is happening is: 1) the inner cable braids are de-braiding and this causes them to act slightly spongy even though the metal itself isn't stretching; 2) the inner-liner of the outer cable gets worn and as a result the inner cable can move more than it's supposed to and this causes stretch; and 3) the outer cable can also de-braid slightly which causes stretch. – RoboKaren Mar 11 '18 at 5:50
  • Replacing the cables can make a big difference if there's friction in them too, especially at the back where there are more bends in the cable. With excessive friction your effort goes into bending the cable rather than moving the brake arms – Chris H Mar 11 '18 at 7:09
  • The test here is to disconenct the inner wire from the brake, and pull it back and forth through the outer. There should be minimal friction. The cable won't drop through under gravity alone, but its not a lot more. – Criggie Mar 11 '18 at 9:06

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