Results 1 to 4 of 4

Thread: Changing Chain length to suit Rear Mech

  1. #1
    Junior Member
    Join Date
    Sep 2010
    Location
    N. Wales
    Posts
    8

    Changing Chain length to suit Rear Mech

    I'm after a bit of advice; I'm currently using a Shimano Alivio rear mech, a friend has given me his old (nearly new really ) Deore XT rear mech, I have noticed that the small chain wheels are smaller on the XT mech than the Alivio, does this mean I will have to shorten the chain slightly? or will it make no real difference?
    Cannondale SL Trail
    Giant Trance X3

  2. #2
    Senior Member fredmundo's Avatar
    Join Date
    Jun 2008
    Posts
    11,063

    Re: Changing Chain length to suit Rear Mech

    Hi MG, do you mean the arm with the sprockets attached too or do you mean the actual sprockets?

    If it's just the sprockets then I'd not bother. if the arm is shorter and you use a triple ring up front then you may find you will need to definitely shorten it, probably a bit more than you think, and then also be careful with your gear discipline too.
    "Duct tape is like the force: It has a dark side and a light side and it holds the universe together."- Carl Zwanzig

  3. #3
    Junior Member
    Join Date
    Sep 2010
    Location
    N. Wales
    Posts
    8

    Re: Changing Chain length to suit Rear Mech

    Thanks for your reply fredmundo.

    It's just the 'Jockey Wheels' are a smaller diameter, the Rear mech is a 'Long Cage' version and therefore still the same length as my current one, and should be suitable for a triple ring set-up.

    My thoughts are the same as yours; as it's just the Jockey Wheels, I'll leave it as it is for now, I'll report back if I needed to make any adjustments, or it caused any problems
    Cannondale SL Trail
    Giant Trance X3

  4. #4
    Senior Member
    Join Date
    Aug 2009
    Location
    Village near Grantham
    Posts
    10,172

    Re: Changing Chain length to suit Rear Mech

    There are several methods to determine the correct chain length; try this one:

    Put the chain over the biggest ring and largest sprocket, with the chain running through the jockey wheels as normal. The derailleur cage should be pointing forward and at about 45 degrees to the horizontal. If the cage is pointing straight down, then you will probably be able to remove a couple of links. Try nipping the chain together to see what happens to the cage angle.

    If you have a full suss bike, then do the assessment with the rear suspension fully compressed. (Either let the air out or ask a heavy friend to assist).

    If the chain is too slack, you will have an increased risk of the following:
    # Chain coming off.
    # Chain rattling on the chainstay.
    # Chainsuck.

    Happy fettling!
    If you can't learn to do something well, learn to enjoy doing it poorly.
    # Norco Sight 1
    # Kona Kula

Similar Threads

  1. Problem with chain length?
    By dizzyblonde82 in forum Technical (maintenance & workshop)
    Replies: 13
    Last Post: 10-Sep-2011, 04:14 AM
  2. How short can you go on chain length?
    By steve_sordy in forum Technical (maintenance & workshop)
    Replies: 6
    Last Post: 10-Oct-2010, 12:01 PM
  3. Chain broke and took out my rear mech!
    By Mark_G in forum Technical (maintenance & workshop)
    Replies: 11
    Last Post: 14-Apr-2010, 07:34 PM
  4. Chain length
    By DomDom in forum Technical (maintenance & workshop)
    Replies: 10
    Last Post: 18-Feb-2010, 07:44 AM
  5. Correct Chain Length
    By NogintheNog in forum Technical (maintenance & workshop)
    Replies: 5
    Last Post: 06-May-2009, 01:04 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
  •