Advertise on Bikeforums.net



User Tag List

Results 1 to 13 of 13
  1. #1
    Master Shake zapb42's Avatar
    Join Date
    Apr 2005
    Location
    Grand Forks, ND
    My Bikes
    IRO Mark V Pro, No-name brand full-suspension mtb (heavy as a tank, but takes a thrashing)
    Posts
    139
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Odd Chainring Question

    PLEASE forgive me if some kind of search might help me here, none of the terms I tried turned up anything.

    Basically my chain will go slack and then tight with each revolution of the chainring, not so much that I notice when riding other than the sound changing, but still enough that it can go from almost totally tight to about 1/2 inch of slack (based on my perception, not actual measurement). I tried loosening all the chainring bolts and shifting the chainring around, but that didn't help.

    I guess I'm trying to see if anyone else has experienced this and/or might have some sort of advice about it. Thanks!

  2. #2
    not so much. zerobug's Avatar
    Join Date
    Jul 2005
    Location
    salem, OR
    My Bikes
    EAI Bare Knuckle track, Gianni Motta track, Lemond road bike, Nishiki road fixed conversion, piles of parts.
    Posts
    314
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    That's a lot of slack, what kind of chainring is it? Turn the bike on its side and pedal the crank, if the chain doesn't fall off it should be ok but I'd just go buy another chainring.

  3. #3
    Senior Member MrCjolsen's Avatar
    Join Date
    Nov 2004
    Location
    Davis CA
    My Bikes
    Surly Cross-Check, '85 Giant road bike (unrecogizable fixed-gear conversion
    Posts
    3,954
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Does your chainring say "biopace" on it?

    But seriously, a lot of "round" chainrings are not exactly so. I wouldn't worry about it.

    When you tighten your back wheel, pay attention to how the cranks are positioned. If you like your chain tension piano-wire tight, position your cranks where they would be on the slack side. If you like a little slack (as I do) then position them where they would be when the chain tightens up.

  4. #4
    Master Shake zapb42's Avatar
    Join Date
    Apr 2005
    Location
    Grand Forks, ND
    My Bikes
    IRO Mark V Pro, No-name brand full-suspension mtb (heavy as a tank, but takes a thrashing)
    Posts
    139
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Its a Rocket that came on my IRO. Yeah it doesn't fall off. Seems like a pretty structurally substantial ring, there's not any way I warped it somehow?

  5. #5
    Doortrapper popluhv's Avatar
    Join Date
    Nov 2005
    Location
    Syracuse, NY
    Posts
    892
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I just got a rocket, and it is surprisingly ovalized for such a large chunk of aluminium. and yeah, i noticed it before i rode on it, so it isn't anything you did to it while riding. i think it's just the manufacturing.

  6. #6
    Senior Member sers's Avatar
    Join Date
    Oct 2005
    Location
    Salem, MA
    My Bikes
    Land Shark, Level Professional, Tsunami singlespeed, Giant Reign 1
    Posts
    2,190
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    this can be alleviated by recentering the chainring on the crank spider. sheldon has instructions here under the "Chain Tension" section.

    i had the same problem with my iro crankset, and I could never get it to the point where the chain tension didn't vary considerably. i ended up replacing it with a sugino 75 crankset & ring and I couldn't be happier.

  7. #7
    Master Shake zapb42's Avatar
    Join Date
    Apr 2005
    Location
    Grand Forks, ND
    My Bikes
    IRO Mark V Pro, No-name brand full-suspension mtb (heavy as a tank, but takes a thrashing)
    Posts
    139
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I suppose I may be being too sensitive about it, it all still works I guess.

  8. #8
    Master Shake zapb42's Avatar
    Join Date
    Apr 2005
    Location
    Grand Forks, ND
    My Bikes
    IRO Mark V Pro, No-name brand full-suspension mtb (heavy as a tank, but takes a thrashing)
    Posts
    139
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Cool, thanks for the link, might help.

  9. #9
    Doortrapper popluhv's Avatar
    Join Date
    Nov 2005
    Location
    Syracuse, NY
    Posts
    892
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I don't think you are being too sensitive, it [I]is[I] annoying. It shouldn't cause any major problems, as long as it isn't super tight at its tightest point.

  10. #10
    Car Fodder
    Join Date
    Jan 2006
    Location
    Philly
    My Bikes
    Schwinn Worldsport Converstion, Fuji Track, Fuji Boulevard, Magneet Sprint
    Posts
    59
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    All this means is that your chainring is not perfectly round. I've heard about these problems with alot of low-mid range rings. My TA Spec was a little oblate right out of the box, it pissed me off. The only real option you have is to upgrade the ring. But this is not really necessery if it doesn't both you that much. Just make sure that when you check your chain tension as part of scheduled maintainence that you check it all the way around the ring.

  11. #11
    Master Shake zapb42's Avatar
    Join Date
    Apr 2005
    Location
    Grand Forks, ND
    My Bikes
    IRO Mark V Pro, No-name brand full-suspension mtb (heavy as a tank, but takes a thrashing)
    Posts
    139
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Yep I'm definitely still learning about all this stuff. I think I improved the situation and in any case it seems like something that is live-withable unless I want to buy a more pricey chainring (which at the moment I cannot)

    Thanks for the input.

  12. #12
    crotchety young dude el twe's Avatar
    Join Date
    Jan 2005
    Location
    SF, CA
    My Bikes
    IRO Angus; Casati Gold Line; Redline 925; '72 Schwinn Olympic Paramount
    Posts
    4,818
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I had the same problem with my Rocket Ring.
    Quote Originally Posted by CardiacKid View Post
    I explained that he could never pay me enough cash for the amount of work I had put into that bike and the only way to compensate me for it was to ride the hell out of it.
    IRO Angus Casati Gold Line

  13. #13
    dig dig dig Moximitre's Avatar
    Join Date
    Jan 2006
    Location
    Chicago
    My Bikes
    Full Fendered Bareknuckle, Faggin with 10spd Centaur, 1973 Raleigh 3spd Cruiser.
    Posts
    878
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    well, my rocket ring seems to be doing the same, perhaps I'm not insane.
    Sucks to your ass-mar!

Posting Permissions

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