Results 1 to 6 of 6
  1. #1
    Off the saddle
    Reputation: jizzim's Avatar
    Join Date
    Dec 2006
    Posts
    211

    Chain size 40t -> 34t (update.. look ok?)

    Sorry guys. I know, not another chain size question..

    Right now I'm running a 2x9 setup with a 40/27 front. I'm going to be converting it to a 1x later this week and will dropping down to a 34t front. Is the difference in tooth size drastic enough to warrant shortening of the chain?
    Last edited by jizzim; 05-15-2013 at 07:48 PM.

  2. #2
    Always Learning
    Reputation: BruceBrown's Avatar
    Join Date
    Jan 2004
    Posts
    8,870
    Quote Originally Posted by jizzim View Post
    Sorry guys. I know, not another chain size question..

    Right now I'm running a 2x9 setup with a 40/27 front. I'm going to be converting it to a 1x later this week and will dropping down to a 34t front. Is the difference in tooth size drastic enough to warrant shortening of the chain?
    Not "drastic", but depending on your derailleur's cage length and whether or not this will be on a fully or HT - it wouldn't hurt to remove a pair of links or so. If you have a chaintool, it is übereasy to do yourself.

    I went from a triple 23/30/40 to the 1 x 9 Rotor Q Ring 34T and didn't shorten the chain at all. Of course, the Rotor 34T in its large spot of the oval is more like a 37T - so that is not very different from a 40T. I will probably remove a pair of links next time I clean the chain.
    The 14 warmest years have all occurred in the 16 years since 1997.

  3. #3
    Off the saddle
    Reputation: jizzim's Avatar
    Join Date
    Dec 2006
    Posts
    211
    I knew I was missing vital info. The cage length is medium and on a FS.

  4. #4
    Always Learning
    Reputation: BruceBrown's Avatar
    Join Date
    Jan 2004
    Posts
    8,870
    Quote Originally Posted by jizzim View Post
    I knew I was missing vital info. The cage length is medium and on a FS.
    Follow the rules of setting chain length for a full suspension frame.

    Good guide on how to do it here for a fully...

    Tech Tuesday - Chain Length Basics - Pinkbike
    The 14 warmest years have all occurred in the 16 years since 1997.

  5. #5
    Off the saddle
    Reputation: jizzim's Avatar
    Join Date
    Dec 2006
    Posts
    211
    Thanks BruceBrown. As simple as the concept is, I didn't think about sizing with the rear fully bottomed out.

  6. #6
    Off the saddle
    Reputation: jizzim's Avatar
    Join Date
    Dec 2006
    Posts
    211
    Night and day difference. My legs are pretty strong (I think) but the 34t made a huge difference. On another note, why didn't I switch to 1x a long time ago?

    So I resized the chain this evening and ended up taking off 3 links after the 1x conversion. Goodbye Duo, hello Uno.
    Tell me what you think.. Even at full compression the chain doesn't feel super tight. It's taut, not tight, and has some "bounce" to it although the picture makes it seem otherwise looking at the derailleur angle.

    Large-large (Rear shock fully extended) The derailleur is about a 45 deg angle.


    Large-large (Rear fully compressed) The derailleur looks super stretched but there's more room for it to lift up so to speak. It's not even close to the instructional link above on Pinkbike. I can still pedal the bike. I don't hear any binding.



    Pinkbike.. Chain too tight
    Last edited by jizzim; 05-15-2013 at 06:13 PM. Reason: New pics and words

Similar Threads

  1. Help with chain-ring size vs. chain length...
    By firstRWD in forum Singlespeed
    Replies: 4
    Last Post: 04-20-2013, 09:33 PM
  2. Which Chain Whip? (Size)
    By STidrvr in forum Tooltime
    Replies: 1
    Last Post: 04-01-2013, 11:19 AM
  3. What size chain do I need?
    By snmhanson in forum Drivetrain - shifters, derailleurs, cranks
    Replies: 1
    Last Post: 08-16-2012, 06:15 PM
  4. SS Chain Size Difference
    By OneArm in forum Singlespeed
    Replies: 7
    Last Post: 03-18-2012, 12:35 AM
  5. Chain size question
    By MTBKR-328 in forum Beginner's Corner
    Replies: 6
    Last Post: 11-27-2011, 09:41 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
  •