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how do you measure brake drop?

shefbikershefbiker Posts: 255
edited July 2014 in Workshop
The title says is really...
I'm looking to swap the hydraulic set-up on my cannondale badboy commuter for a conventional canti set-up (because old avid jucies area nightmare) so i'm trying to measure up.

What's the best way to do it?
Thanks

Posts

  • sungodsungod Posts: 12,212
    for brakes mounted via the central hole at the top of the fork, drop is the vertical distance from the axis of the hole to the centre line of the brake pad

    more here (sb calls it 'reach' instead of drop)...
    http://sheldonbrown.com/calipers.html#reach

    assuming this is what you're intending to use, you'll probably need a long drop brake, shimano r650 for instance go up to 57mm drop
    my bike - faster than god's and twice as shiny
  • keef66keef66 Posts: 13,286
    Not vertical but diagonal; this from the Sheldon article you linked to:

    "This is measured from the centerline of the center bolt diagonally down to the middle of the brake shoe"
  • Ben6899Ben6899 Posts: 7,225
    keef66 wrote:
    Not vertical but diagonal; this from the Sheldon article you linked to:

    "This is measured from the centerline of the center bolt diagonally down to the middle of the brake shoe"

    Correct, but it won't make much difference over ~50mm with a typical rim width. Either method will place you in the right ballpark of "standard" or "long" drop.
    Ben

    Bikes: Donhou DSS4 Custom | Condor Italia RC | Gios Megalite | Dolan Preffisio | Giant Bowery '76
    Instagram: https://www.instagram.com/ben_h_ppcc/
    Flickr: https://www.flickr.com/photos/[email protected]/
  • The MechanicThe Mechanic Posts: 1,277
    Ben6899 wrote:
    keef66 wrote:
    Not vertical but diagonal; this from the Sheldon article you linked to:

    "This is measured from the centerline of the center bolt diagonally down to the middle of the brake shoe"

    Correct, but it won't make much difference over ~50mm with a typical rim width. Either method will place you in the right ballpark of "standard" or "long" drop.


    That is true but the OP was asking how to measure. Isn't is best to give him the correct answer?
    I have only two things to say to that; Bo***cks
  • Ben6899Ben6899 Posts: 7,225
    Ben6899 wrote:
    keef66 wrote:
    Not vertical but diagonal; this from the Sheldon article you linked to:

    "This is measured from the centerline of the center bolt diagonally down to the middle of the brake shoe"

    Correct, but it won't make much difference over ~50mm with a typical rim width. Either method will place you in the right ballpark of "standard" or "long" drop.


    That is true but the OP was asking how to measure. Isn't is best to give him the correct answer?

    No you're right. I shouldn't be derailing threads with minor details.

    Sorry, OP. Measure diagonally. If it's not much more than 45mm, you can file away at a Campag brake to get a couple extra mm.
    Ben

    Bikes: Donhou DSS4 Custom | Condor Italia RC | Gios Megalite | Dolan Preffisio | Giant Bowery '76
    Instagram: https://www.instagram.com/ben_h_ppcc/
    Flickr: https://www.flickr.com/photos/[email protected]/
  • shefbikershefbiker Posts: 255
    thank you chaps for taking the time to reply.
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