Cable routing for crossbike rear brake?

joeyhalloran
joeyhalloran Posts: 1,077
edited December 2011 in Workshop
Hi,

I have recently purchased a (secondhand) crossbike for winter cycling/commuting etc...

When I first got it the rear brake was very hard to pull (I couldn't do it from the drops and it took real effort from the hoods). I assumed this was due to the brake cable so today I went out and purchased a new brake cable, I installed it with fairly flowing lines (as much as the brake cable guide on the top tube would allow) and connected up the cantilever brake...however when I tighten it the brake to an appropriate distance from the rim it is still very hard to pull. The cable seems to be able to move through the outer parts ok (if its not in the brake and I hold it the leave moves ok (not perfectly though). Its just as soon as I attach the brake on the end it becomes unusable, is there a trick to cantilever brakes? I have only ever had calliper brakes before, which from my experience so far are much much better (both in stopping distance and feel) but I assume this is due to something I am doing.

Comments

  • Monty Dog
    Monty Dog Posts: 20,614
    http://www.cxmagazine.com/gut-wrenching ... rake-setup

    There is an art to setting up cantis and by the sounds of it you're doing the right things - hopefully the above will give you a few more pointers. Also make sure that the outer isn't kinked and that the liner is opened-out at the ends - use a decent quality make too - some cheap ones compress easily.
    Make mine an Italian, with Campagnolo on the side..
  • nicklouse
    nicklouse Posts: 50,675
    I prefer this topic on cantis

    http://www.parktool.com/blog/repair-hel ... ke-service
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • joeyhalloran
    joeyhalloran Posts: 1,077
    Well, i read both of them and tried again, but still no luck. I can either have it so I can pull the brake lever and the pads barely touch the wheel, or have a proper brake effect but be unable to pull the level...neither really seem acceptable. I have also noticed that, despite the screws pushing the pads in/out being at the limit, the right hand pad is much further away from the rim than the left hand pad (as in the screws pushing the right hand pad in and left hand pad out).

    Maybe its time to take it to a shop, cantilever brakes are to complicated and confusing for me!
  • Monty Dog
    Monty Dog Posts: 20,614
    Strip everything off and start again? If you've got post mount pads, make sure they're evenly spaced either side. Likewise, make sure the springs and fitted in the same position holes each side - use the bottom ones to reduce the spring load. When the arms are fitted, make sure they pivot freely. What make are your brakes? Some are far easier to set up than others.
    Make mine an Italian, with Campagnolo on the side..
  • joeyhalloran
    joeyhalloran Posts: 1,077
    They are some cheap shimano ones I think (they are quite old). I did try to take it off but it seems that its slightly stripped and I didn't want to make it worse, I may have another go when I have a 'better' allen key (my ones are the ball end types for different angles, but I find they aren't as good at slightly threaded bolts).

    Thanks for the suggestions though.
  • joeyhalloran
    joeyhalloran Posts: 1,077
    http://www.google.co.uk/products/catalo ... CHUQ8wIwAA

    These ones I think.
  • MichaelW
    MichaelW Posts: 2,164
    You can adjust the mechanical advantage of the brake system by altering the length of the straddle cable. A good explanation by Sheldon Brown.
  • joeyhalloran
    joeyhalloran Posts: 1,077
    hmm, maybe I just need a bucket load more MA. It would need to be a lot though.

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