Advertise on Bikeforums.net



User Tag List

Results 1 to 19 of 19
  1. #1
    Senior Member aMull's Avatar
    Join Date
    Aug 2006
    Location
    Toronto
    My Bikes
    Leader 735TR 09 58cm 46/17
    Posts
    1,777
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Help with chain tension

    I'm putting my new bike together and i'm trying to even out the chain tension. I know what i'm supposed to do with loosening ring bolts and then micro adjusting the tension, but it doesnt work. I checked and the chainring seems to be free of wobble, the cog has zero wobble, but there is still a big difference in tension between two opposite crank positions. I tried rotating the chainring position around to see if that was causing, but each time the tight/slack occurs at the same points. So what else? Chain tension is just about the worst thing about the fixed gear
    Quote Originally Posted by Mark Hertsgaard
    The car is not only tainting the present but devouring the past and threatening the future.

  2. #2
    Fresh Garbage hairnet's Avatar
    Join Date
    Apr 2009
    Location
    Los Angeles
    Posts
    10,713
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    I just get the chain just under tight on the "loose spot" of the ring so it's tight on "tight spot" but not extremely
    Quote Originally Posted by Scrodzilla View Post
    I'd rather ride a greasy bowling ball than one of those things.
    Bikerowave
    My Bikes

  3. #3
    neato teedoff087's Avatar
    Join Date
    Oct 2009
    Location
    Tyler, TX
    My Bikes
    2010 Moto Track
    Posts
    170
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Chainrings aren't perfectly circular. It's just something you have to deal with. You just need to make sure that the chain doesn't bind at the tight spot or else you'll wear your drivetrain out quicker.

  4. #4
    Senior Member aMull's Avatar
    Join Date
    Aug 2006
    Location
    Toronto
    My Bikes
    Leader 735TR 09 58cm 46/17
    Posts
    1,777
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I understand that but the problem is that the difference is just too big. My previous bike had uneven chain tension too, but not this much. I'm just wondering what else can i check?
    Quote Originally Posted by Mark Hertsgaard
    The car is not only tainting the present but devouring the past and threatening the future.

  5. #5
    Senior Member cnnrmccloskey's Avatar
    Join Date
    May 2009
    Location
    Portland Oregon
    My Bikes
    '82 Giante super challange, 70 Gitane Tour de France, GT Gutterball
    Posts
    745
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by aMull View Post
    I understand that but the problem is that the difference is just too big. My previous bike had uneven chain tension too, but not this much. I'm just wondering what else can i check?
    Do you notice it while you ride?

  6. #6
    cab horn
    Join Date
    Jun 2004
    Location
    Toronto
    My Bikes
    1987 Bianchi Campione
    Posts
    28,292
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by aMull View Post
    I understand that but the problem is that the difference is just too big. My previous bike had uneven chain tension too, but not this much. I'm just wondering what else can i check?
    If you've already tried the chainring trick there is nothing else to do besides new components and a new frame. Some combinations will be worse than others. Live with it or start spending money which may or may not "fix" it. If you're not dropping the chain on bumps with correctly tensioned chain then there isn't a functional problem.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  7. #7
    cab horn
    Join Date
    Jun 2004
    Location
    Toronto
    My Bikes
    1987 Bianchi Campione
    Posts
    28,292
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by hairnet View Post
    I just get the chain just under tight on the "loose spot" of the ring so it's tight on "tight spot" but not extremely
    This is not correct.

    The drivetrain should not result in a laser tight, binding drivetrain at any point of the rotation.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  8. #8
    Senior Member chi-james's Avatar
    Join Date
    Sep 2009
    My Bikes
    team miyata, '73 p-14, MB-3, centurion lemans, Mystery TT, mongoose atb '85
    Posts
    331
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    this is probably a dumb question, but it happened to me once... are you sure that your chainring is not biopace?

    it was a dumb question... didn't read the op closely, e.g. "new" bike, etc...
    Last edited by chi-james; 02-07-10 at 08:16 PM.

  9. #9
    Senior Member Steev's Avatar
    Join Date
    Jul 2005
    Location
    Backwoods of Ontario
    Posts
    2,123
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    If the tight spot follows crank position even with rotating the ring one bolt position, that would suggest something like a bent crank spindle or ecentricity somehow with the BB.

  10. #10
    Senior Member aMull's Avatar
    Join Date
    Aug 2006
    Location
    Toronto
    My Bikes
    Leader 735TR 09 58cm 46/17
    Posts
    1,777
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Steev View Post
    If the tight spot follows crank position even with rotating the ring one bolt position, that would suggest something like a bent crank spindle or ecentricity somehow with the BB.
    Yep tried rotating the chaining around and the loose/tight positions are the same. The frame and bb are brand new, and the bb was installed by the shop a few days ago.

    Or it might suggest something with the spider. I guess ill live with it for a while but i'd always worried about dropping the chain.
    Quote Originally Posted by Mark Hertsgaard
    The car is not only tainting the present but devouring the past and threatening the future.

  11. #11
    Senior Member
    Join Date
    Jun 2009
    Posts
    332
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Can you force the chain off at the loosest point (push the chain to the side while turning the cranks, as though you were derailing the chain)? If not, or if it's pretty difficult, then I wouldn't worry too much about it. Also, make sure you don't have any stiff links in your chain. Chances are, the issue is probably not something worth paying attention to.

  12. #12
    Senior Member aMull's Avatar
    Join Date
    Aug 2006
    Location
    Toronto
    My Bikes
    Leader 735TR 09 58cm 46/17
    Posts
    1,777
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yeah maybe you're right. Its just that i know the chain tension should be more even, like it was with my previous bike. Oh well. Ive never had a chain come off, what exactly happens when it does?
    Quote Originally Posted by Mark Hertsgaard
    The car is not only tainting the present but devouring the past and threatening the future.

  13. #13
    a.k.a. QUADZILLA LoRoK's Avatar
    Join Date
    May 2007
    Location
    Portland!
    My Bikes
    Super Pista
    Posts
    1,499
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by aMull View Post
    Ive never had a chain come off, what exactly happens when it does?
    ..

  14. #14
    Senior Member aMull's Avatar
    Join Date
    Aug 2006
    Location
    Toronto
    My Bikes
    Leader 735TR 09 58cm 46/17
    Posts
    1,777
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Well i measured the chain travel and the loose spot moves ~10-12mm more than the tight spot (total travel up+down). Not sure if this is a lot, but sure looks a lot.
    Quote Originally Posted by Mark Hertsgaard
    The car is not only tainting the present but devouring the past and threatening the future.

  15. #15
    neato teedoff087's Avatar
    Join Date
    Oct 2009
    Location
    Tyler, TX
    My Bikes
    2010 Moto Track
    Posts
    170
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    If it doesn't derail easily, it's fine. 10-12 mm sounds about right.

  16. #16
    Fresh Garbage hairnet's Avatar
    Join Date
    Apr 2009
    Location
    Los Angeles
    Posts
    10,713
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by operator View Post
    This is not correct.

    The drivetrain should not result in a laser tight, binding drivetrain at any point of the rotation.
    the "extremely" tight part is what I meant for laser tight, binding.
    Quote Originally Posted by Scrodzilla View Post
    I'd rather ride a greasy bowling ball than one of those things.
    Bikerowave
    My Bikes

  17. #17
    cab horn
    Join Date
    Jun 2004
    Location
    Toronto
    My Bikes
    1987 Bianchi Campione
    Posts
    28,292
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by aMull View Post
    Well i measured the chain travel and the loose spot moves ~10-12mm more than the tight spot (total travel up+down). Not sure if this is a lot, but sure looks a lot.
    There is an easier way to determine if a paritcuarly drivetrain will drop a chain. Manually try to derail the chain to the inside while pedalling the bike on the stand. If the chain does not come off while doing this test, then it won't come off on the road.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  18. #18
    Senior Member
    Join Date
    May 2008
    Location
    Davis/Lafayette, CA
    My Bikes
    1984 trek 460 conversion, 2008 Lynskey R320, Peloton track bike, 1990's MBK trainer, 2004 Fisher tassajara, 70's Raleigh Gran prix. 70's moto mirage conversion (stolen), 80's Shogun Kaze (sold)
    Posts
    2,015
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    i like at the tightest point to have at least 5mm of travel. 10 is fine imo. i like max under 20mm or so

    if it's still bothering you, have you tried rotating your chainring (like unbolting it from the arm, then rebolting it one hole over). maybe the arm and the ring are each a little out of round, but they're lined up and working against each other.

    i wouldn't worry about it though.

  19. #19
    Senior Member aMull's Avatar
    Join Date
    Aug 2006
    Location
    Toronto
    My Bikes
    Leader 735TR 09 58cm 46/17
    Posts
    1,777
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yes i tried all five position and still the same thing at the same place. So i dont know what the problem is, its just annoying visually seeing the chain go tight and then go slack
    Quote Originally Posted by Mark Hertsgaard
    The car is not only tainting the present but devouring the past and threatening the future.

Posting Permissions

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