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Questions

Q1. For rear cantilever brakes, are there any off-the-shelf parts or brake designs that route a rear brake cable from underneath the saddle cable instead of above?

Q2. If not, then can anyone suggest an improvised, but proven setup using existing, readily-available parts?

Q3. What concerns should I have with a reverse-pull cantilever brake setup (e.g. safety, maintenance)?

Background

I have a mixte frame with standard rear cantilever brake bosses on the seat stays, with standard cantilever brakes such as these:

classic wide cantilever brakes

Since the frame is a mixte, the rear brakes are higher than the "top tube" of the mixte, along which runs my rear brake cable.

I've seen that some mixtes use a reverse cable attachment to side-pull caliper brakes so that the cable makes a single arc from the top tube to the brakes. My goal is to roughly mimic this cable routing, but with cantilever brakes instead. Here is an example (but mine does not have a rack to work around):

a reverse-pull caliper brake setup

The original build is pictured below (not the actual bike, but same model, etc.) and has the rear brake cable running along the "top tube", curving along the back of the seat tube, and then going over a pulley that is attached to the seat tube clamp bolt. That pulley acts as a housing stop and so it's a center-pull from the top. I am looking to improve the rear brake responsiveness, put less stress and wear on the cable, and have fun engineering a more elegant solution.

Schwinn Mirada rear brake setup

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    How is it routed originally? Is this a new build?
    – WTHarper
    Commented Nov 1, 2013 at 19:38
  • @WTHarper, I added the route of the original build into the question. I hope that helps, thanks!
    – PositiveK
    Commented Nov 1, 2013 at 20:26
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    The pulley approach is the most obvious and straight-forward solution to this. Another option would be to wrap a long straddle cable around a tubular form placed roughly where the mirror mounts in the lower picture, then have the "junction" of the cable meet the main cable about midway between the upper and lower seat stays. (Using pulleys would constrain the cables horizontally too much, but it's hard to say how much friction would be in a roughly 1" radius curved shape.) Or you could maybe somehow use two "noodles" from V brakes.
    – Daniel R Hicks
    Commented Nov 6, 2013 at 22:56

4 Answers 4

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You can't do this with traditional cantilever brakes, because the straddle wire has to be pulled from above to tension it - attempting to pull it from below would pull into the wheel.

You could pull from the side by using direct pull cantlievers, a.k.a. v-brakes. A Problem Solvers "Travel Agent" could probably be hacked up to work, and a clean implementation could probably be done with one of the no-longer-produced World Class "V-Daptor" adapters, if you could find one.

That said, both of those approaches are probably less elegant than the already-existing pulley method that it sounds like already works on the frame.

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    I was thinking that a V brake would be the way to go. Maybe one could modify the noodle to pull from below somehow...
    – WTHarper
    Commented Nov 2, 2013 at 22:04
  • @WTHarper: Yeah! Exactly my original improvised plan. I am going to try the noodle attached to the transverse cable yoke, and run the bare cable up to a standard cable hanger at the seattube clamp where it will have a little cable clamp to hold it fixed. There is the issue of clearance as lantius mentioned: between yoke and tire, but also considering the metal reflector bracket that sits between tire and yoke.
    – PositiveK
    Commented Nov 6, 2013 at 20:17
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    @WTHarper Update: I removed the cable anchor bolt from an old aluminum saddle cable hanger. I bent the bolt hole towards the side with the curled lips that hold the saddle cable, to a 90 deg angle. I inserted a noodle's tip into that to create the lower pull point as discussed above. However, the noodle bend bumps into the hanger causing the cable to emerge from the noodle at a slight angle instead of straight out. This made it rub against the noodle's sharp tip edge. So I abandon that approach until I find a piece/way to attach the hanger further down to leave clearance for the noodle.
    – PositiveK
    Commented Nov 22, 2013 at 1:40
  • Interesting...photos would be great!
    – WTHarper
    Commented Nov 22, 2013 at 1:58
  • The v-brake noodle is direction agnostic, like caliper brakes. Personally, I would invest in better brake pads and cable housing, and, if necessary, brake levers. Those are good investments on their own and worth doing even if it doesn't solve your problem (in which case, v-brakes are good, just remember the cable-pull issue).
    – Nathaniel Hoyt
    Commented Sep 25, 2020 at 23:35
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I did a similar modification once, for a slightly different objective.

I installed cantilever brakes with a cable route that simulated the direct-pull cable routing. I solved the tire-cable clearance issue by using the original cable stop to install a hanger that would keep the cable from interfering with the tire.

The cantilever side that has a screw to tighten the cable was left as is, the other one has a shape to hold a cable nut. I modified it to hold a ferrule for the cable hose.

The results were a very powerful cantilever brake installation where the cable from them is routed the other way (this was unintended for me). Reliability was as good as normal linear pull brakes. I performed several tests, particularly to assess that no component fell out of place when the bike was subjected to heavy shock, shaking, etc. This testing was done in a selected environment to reduce the possibility of injury in case of failure.

The downside was that to remove the wheel I had to remove the cable from the hanger, and then it interfered with the tire, so the whole operation was more fiddly than with other setups.

I trusted the setup enough to do short downhill trail riding (like in DH riding)

Disclaimer: I share my experience, but it is not recommended to modify brake systems unless you have good knowledge about its working principles and experience installing, maintaining or repairing normal or standard set ups. Good tooling skills are also a must.

I no longer own the bike and I never took a picture of the setup. Here is a drawing of what I remember.

enter image description here

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  • Interesting - Did the cable slide over the saddle hanger or did it pull the saddle hanger toward the hose?
    – Criggie ♦
    Commented Sep 23, 2018 at 4:04
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    @Criggie the saddle hanger is "floating" as is held by a short piece of cable (about 4 centimeters or 2 inches) so it moves side to side when the main cable slides.
    – Jahaziel
    Commented Sep 24, 2018 at 14:41
  • clever! i'm not sure I would trust this on my own rigs but I always appreciate ingenuity.
    – Nathaniel Hoyt
    Commented Sep 25, 2020 at 23:35
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As always ask Sheldon Brown!

I don't know if it will work because he's talking about centre pulls, but anyway, you need to attach the cable housing to the yoke, and the cable is then attached where the pulley is in your picture. The cable housing will then push the yoke up towards the seat tube instead of the cable pulling up the yoke!

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I would use the pulley but route the cable housing up the seat tube.

Rotate the pulley so that the stop is horizontal then the bare inner cable uses the pulley almost as a guide rather than as a traditional top friction wheel. This is because the pulling force is downwards.

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