Results 1 to 12 of 12
  1. #1
    mtbr member
    Reputation: Calhoun's Avatar
    Join Date
    Nov 2008
    Posts
    1,732

    FS SS help (chain skip)

    Can someone tell me what I am doing wrong?

    I have a Jet9 that I really want to ride, but my wheelset is still a couple weeks out. So I took the wheels off of my Monocog and tried to set up the Jet as a SS. I trying to do this without buying new parts because when the wheels come in this bike will be geared and the Mono will take care of my SS responsibilities. So I am using an older XT 8 speed derailleur, and I everything "looks" great, but when I test it around the block the chain skips or falls off. I have tried a new chain, a shorter chain, a longer chain and even no chain! I even set up the shifter to try and hold tension on the derailleur.

    The threads I read about chain skipping related back to chain wrap. But looking at the pictures of successful conversions I have as much and sometimes more chain wrap.

    What am I missing?
    Last edited by Calhoun; 03-03-2009 at 08:05 AM.

  2. #2
    Happy in Happy Valley
    Reputation:
    Join Date
    Jun 2008
    Posts
    681
    How does your chainline look?
    Rigid Surly 1x1 650b--------Fixed CrossCheck--------Surly Pacer-------Salsa Ala Carte

  3. #3
    mtbr member
    Reputation: Calhoun's Avatar
    Join Date
    Nov 2008
    Posts
    1,732
    straight, and the derailer cogs line up straight with the cog also.


    this is a pic before the test ride. The chain is shorter now.

  4. #4
    one chain loop
    Reputation: fishcreek's Avatar
    Join Date
    Apr 2007
    Posts
    2,302
    how about a shot from the top?
    everything sucks but my vacuum cleaner.

  5. #5
    mtbr member
    Reputation: Calhoun's Avatar
    Join Date
    Nov 2008
    Posts
    1,732
    I am at work and that is the only shot I have. The chainline looks like it did on the Monocog. I guess the BB width could be different but I transferred the cranks and rear wheel from the Mono and I thought the chainline was good.

    By adjusting the H/L screws on the derailleur I could ge the the skipping to lessen, but never fully go away.

  6. #6
    mtbr member
    Reputation: brassnipples's Avatar
    Join Date
    Feb 2006
    Posts
    372
    could the hanger be bent? Also it looks like the chain is sagging on top (could be an optical illusion), i've never used a der as a tensioner but I would think that it should provide enough tension to keep the chain flat.

  7. #7
    mtbr member
    Reputation:
    Join Date
    May 2006
    Posts
    262
    New chain, old cog? Perhaps one is worn and they don't line up? Also, 9 speed chain on an 8 speed cog?

    -Rob.

  8. #8
    mtbr member
    Reputation: Calhoun's Avatar
    Join Date
    Nov 2008
    Posts
    1,732
    New(er) cog, new nine speed chain. And it looks slack cause it was, I took out some links and it is not that slack now.

  9. #9
    conjoinicorned
    Reputation: ferday's Avatar
    Join Date
    Jan 2004
    Posts
    3,530
    Quote Originally Posted by Calhoun
    New(er) cog, new nine speed chain. And it looks slack cause it was, I took out some links and it is not that slack now.
    are you supposed to use a 9 spd. chain with the niner cogs? i know surly cogs don't like 9 spd. chains at all, i would highly recommend a less narrow chain....
    what would rainbow unicorn do?

  10. #10
    mtbr member
    Reputation: Calhoun's Avatar
    Join Date
    Nov 2008
    Posts
    1,732
    didn't even think of that. I have an Sram SS chain that I'll try.

  11. #11
    mtbr member
    Reputation: boomn's Avatar
    Join Date
    Jul 2007
    Posts
    9,647
    I checked Niner's website for info and they describe the cog as having a "SS Specific Tooth Profile for Increased Chain Bite". That definitely sounds an issue, as a 9spd chain might not be fitting over the teeth properly (like ferday said)

  12. #12
    mtbr member
    Reputation: Calhoun's Avatar
    Join Date
    Nov 2008
    Posts
    1,732
    Not sure why I didn't think of it, but I had a nine speed chain on the cog when it was on the Monocog and had no issues.

    Guy at the bike shop confirmed the pulleys are shot, and said the cage may be bent. So I did my best to straighten it and plan to get some cheapy pulleys at Performance tomorrow.

    I rode the bike tonight with the derailleur zip ties to the chainstays and I used the shifter to adjust the swing while I rode. First couple miles were frustrating, but once I dialed it in I was happy.

Posting Permissions

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