Advertise on Bikeforums.net



User Tag List

Results 1 to 6 of 6
  1. #1
    Senior Member
    Join Date
    Feb 2006
    Posts
    226
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Changing rotor size from 160mm to 140mm on rear of Surly Karate Monkey...

    Sorry, I know this question has been asked before, but I haven't seen an answer which applies to my specific situation.

    I have a super budget built Surly Karate Monkey. It's got a used Avid BB7 disc brake set on it. The rear caliper looks like it might be some cheap thing which was taken off of a Walmart bike or something. It's very warped, and I can't get it adjusted right. Somebody on my local CL has a used 140mm caliper that can be had for only 10 dollars. The current size on the rear of my bike is 160mm. Can I buy this used 140mm caliper and make it work?

    Thanks,

    - Tim

    http://img705.imageshack.us/img705/2...idrotor140.jpg

  2. #2
    Senior Member mtbikerinpa's Avatar
    Join Date
    Dec 2004
    Location
    PA
    My Bikes
    92 Giant Sedona ATX Custom
    Posts
    1,672
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If your frame is a IS mount instead of a post mount you can get an adapter to either size. I have used both on the rear of my mtb(currently has 140 on the rear 160 front). The 140 rotor is a little harder to lock up, which can be a good thing depending on what you are out for. The adapter is not expensive, so if you get the rotor/caliper combination fitted and find it does not meet just check your shop and they can order it for you.
    Aviation Mechanic, Bike racer, Fitness Equipment Restorer

    http://pedalmybike.com/userTrackies/myTrackie4758.jpg[/url]

  3. #3
    Senior Member
    Join Date
    Feb 2006
    Posts
    226
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by mtbikerinpa View Post
    If your frame is a IS mount instead of a post mount you can get an adapter to either size. I have used both on the rear of my mtb(currently has 140 on the rear 160 front). The 140 rotor is a little harder to lock up, which can be a good thing depending on what you are out for. The adapter is not expensive, so if you get the rotor/caliper combination fitted and find it does not meet just check your shop and they can order it for you.
    This is what my rear mount looks like. I'm assuming this is an IS mount right? Looks pretty adjustable to me.

    http://farm4.static.flickr.com/3405/...7f7af87d22.jpg

  4. #4
    Senior Member
    Join Date
    Mar 2010
    Location
    City of Brotherly Love
    My Bikes
    Raleigh Companion, Nashbar Touring, Novara DiVano, Trek FX 7.1, Giant Upland
    Posts
    1,067
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by tgrssn View Post
    This is what my rear mount looks like. I'm assuming this is an IS mount right? Looks pretty adjustable to me.

    http://farm4.static.flickr.com/3405/...7f7af87d22.jpg
    The adjustibilty you see is there because you have horizontal dropouts. To change rotor size you need to replace the mounting bracket. (see pages 50-52 in http://cdn.sram.com/cdn/farfuture/q-..._spc_rev_a.pdf)

  5. #5
    Senior Member
    Join Date
    Feb 2006
    Posts
    226
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Bezalel View Post
    The adjustibilty you see is there because you have horizontal dropouts. To change rotor size you need to replace the mounting bracket. (see pages 50-52 in http://cdn.sram.com/cdn/farfuture/q-..._spc_rev_a.pdf)
    thanks

  6. #6
    B A N N E D
    Join Date
    Aug 2006
    Posts
    1,014
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    The rear caliper looks like it might be some cheap thing which was taken off of a Walmart bike or something. It's very warped, and I can't get it adjusted right. Somebody on my local CL has a used 140mm caliper that can be had for only 10 dollars. The current size on the rear of my bike is 160mm. Can I buy this used 140mm caliper and make it work?
    Warped caliper ?

    Don't you mean a warped rotor.

    Does the caliper have IS mounts or post mounts ?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •