Effect of Spring Position on Cantilever Brake Performance

Ben_.
Ben_. Posts: 16
edited August 2017 in Cyclocross
After nearly a year in the bike shed (injury, wedding & laziness) , I've got my cross bike out. After a mini-service (and some new wheels) the bike is pretty much back to normal. However (as always) I'm struggling to get the brakes to perform as I want them. This is the only bike I own that has Cantilever brakes as opposed to dual pivot (aka road) brakes, so I don't have the experience/hands-on time to be familiar with the ins and outs of canti-brakes.

I can tinker with the brakes a fair bit, but what I can't understand is what effect the 2/3 spring positions on the mounting bosses has. I've read:
"The top hole gives a sharper return action. The bottom hole makes the cantilever brakes easier to pull on, but in this position they return with less force."
But I can't translate that into how the brakes feel/perform.

I'm fairly happy with the performance of the front brake, however I can't seem to get the rear brake setup how I want it (I can't get the rear brake to apply enough force without needing significant pressure (and hand movement on the brake lever).

Comments

  • tgotb
    tgotb Posts: 4,714
    Ben_. wrote:
    After nearly a year in the bike shed (injury, wedding & laziness) , I've got my cross bike out. After a mini-service (and some new wheels) the bike is pretty much back to normal. However (as always) I'm struggling to get the brakes to perform as I want them. This is the only bike I own that has Cantilever brakes as opposed to dual pivot (aka road) brakes, so I don't have the experience/hands-on time to be familiar with the ins and outs of canti-brakes.

    I can tinker with the brakes a fair bit, but what I can't understand is what effect the 2/3 spring positions on the mounting bosses has. I've read:
    "The top hole gives a sharper return action. The bottom hole makes the cantilever brakes easier to pull on, but in this position they return with less force."
    But I can't translate that into how the brakes feel/perform.

    I'm fairly happy with the performance of the front brake, however I can't seem to get the rear brake setup how I want it (I can't get the rear brake to apply enough force without needing significant pressure (and hand movement on the brake lever).
    That's just adjusting the spring tension. Most cantis have a bunch of other adjustments, including the brake pad position relative to lever (which alters the geometry) and the straddle cable length. There are a few Canti brake experts on here, I'll leave it to one of them to explain the subtleties, but it's a lot more complex than caliper brakes. In general, they can be made to work well if set up correctly, but it's quite easy to get it wrong.
    Pannier, 120rpm.
  • Ben_.
    Ben_. Posts: 16
    TGOTB wrote:
    In general, they can be made to work well if set up correctly, but it's quite easy to get it wrong.

    You can say that again! So far I'm an expert on getting them wrong!
  • liamcahill1
    liamcahill1 Posts: 146
    They are easier to set up as you do it more (get it wrong more)....

    2 key things for me:
    1 is getting the arm that connects to the brake shoe parallel to the rim when the brake pad contacts the rim.
    2 is having a clean system. The bosses, cables and housing should all be clean.

    Softer brake pads are also helpful, but they can be rather expensive.

    What brakes do you have?
  • trek_dan
    trek_dan Posts: 1,366
    Assuming everything else is right the key is getting the movement even and the pads adjusted right. This is harder to achieve with some canti brakes than others but shouldn't be impossible.
  • TonyJams
    TonyJams Posts: 214
    Do a search on google for "Toe in" as well, makes the most difference.
    And make sure your inner cable is super smooth on the outer, replacing if necessary, you want a nice return spring back feeling through your lever too.

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