1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
mtn. biking 101
2. If possible, try to find a shop that will let you demo the bike on real dirt. Five minutes in a parking lot won't cut it. You wouldn't buy a car without a real world test drive, and a bike should be no different.
3. Don't belive the hype. Just because your favorite rider or best friend rides a certain bike, that doesn't mean that's the best one for you. Have an open mind and be realistic about your needs and ability.
Results 1 to 6 of 6
  1. #1
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    3

    Rear wheel/ Drivetrain issue

    Hello everyone, I recently purchased my first mountain bike about a month ago, a 2007 specialized stumpjumper carbon fsr from a friend. The bike has been awesome so far and I have put around 200 miles on it since buying it. The only issue I have had is when I am on a downhill section and have the bike shifted on to the largest (tallest) chainring the rear brakes seem to engage when the suspension is compressed, it makes a low pitched squealing noise, almost as if I were holding the rear brake lever. Sometimes I can get it to stop if I compress the suspension more as I am riding and sometimes it will only stop squealing if I pedal. I like to think I am pretty mechanically inclined and am wondering if it is a quick fix or if I need to take it in to get looked at. The bike has shimano xt crank/chainrings, SRAM front and rear derailers and magura hydraulic brakes. Thank you for any tips.

  2. #2
    mtbr member
    Reputation:
    Join Date
    Nov 2011
    Posts
    2,482
    I'd guess your chain is too short.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Apr 2013
    Posts
    548
    That makes sense.

  4. #4
    mtbr member
    Reputation: lotusdriver's Avatar
    Join Date
    Sep 2013
    Posts
    509
    Remove the shock, turn the bike upside down, and compress the rear suspension fully.

    You can then shift into the higher gesrs and see if the chain is becoming stretched to the limit.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    3
    thanks for the info guys, I will try this tonight.

  6. #6
    mtbr member
    Reputation:
    Join Date
    Oct 2012
    Posts
    748
    Quote Originally Posted by lotusdriver View Post
    Remove the shock, turn the bike upside down, and compress the rear suspension fully.

    You can then shift into the higher gesrs and see if the chain is becoming stretched to the limit.
    doing this may allow the suspension system to compress more than the shock will allow. When you do this, measure the eye-to-eye length of the frame's shock connectors to the (shock length) - (shock travel).

    Might ask your friend if he ever had to remove some links due to a busted chain. A new chain is only $15-$30, so it's not a bad idea to get a new one anyway.

    troubleshooting if the chain isn't the guilty party. Check your brake cables and make sure they don't get kinked when you're compressing the suspension. Bend in the cable may push the rotors in just enough to squeel. downhill section could also be heating up the brakes, which transfers a litle heat to the calipers, which expand the oil, and causes the pads to move in and rub a litle bit.

Similar Threads

  1. Mojo SL rear wheel issue
    By Smilerz in forum Ibis
    Replies: 9
    Last Post: 03-21-2013, 08:03 PM
  2. Help Diagnosing Drivetrain Issue
    By SJKevin in forum Beginner's Corner
    Replies: 4
    Last Post: 07-16-2012, 11:23 AM
  3. 135mm rear wheel axle issue
    By saxen in forum Ibis
    Replies: 2
    Last Post: 09-22-2011, 10:02 PM
  4. Drivetrain Issue
    By nov0798 in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 3
    Last Post: 07-06-2011, 05:26 AM
  5. Drivetrain issue - please help
    By yohyat in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 5
    Last Post: 01-03-2011, 11:10 PM

Posting Permissions

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