Will a high quality chainring eliminate radial runout?- Mtbr.com
Results 1 to 6 of 6
  1. #1
    mtbr member
    Reputation:
    Join Date
    Jun 2012
    Posts
    167

    Will a high quality chainring eliminate radial runout?

    My chain is tighter in one pedal position than in others. Is that typical of low quality chainrings or of all chainrings?

    Suggestions?

  2. #2
    mtbr member
    Reputation:
    Join Date
    Jan 2011
    Posts
    861
    Yes, quality counts.

    Chainrings are generally built and/or finished on CNC machines. Low quality and/or poorly maintained machines move differently in the X vs. the Y position such that parts that need to be round will become slightly oval. Chainrings built on better machines and/or built with a rotary table will generally be more accurate.

    Some slight tight/loose movement is also not a problem and if you use a larger ring/cog your drivetrain will handle the tight/loose just fine. Even with the best rings a very slight tight/loose cycle will occur but it's no big deal and most people don't worry once it is "good enough".

  3. #3
    mtbr member
    Reputation:
    Join Date
    Nov 2011
    Posts
    3,779
    Sometimes you can correct some of the eccentricity by loosening the chainring bolts and re-tightening them. I think there is a Sheldon Brown page about it.

  4. #4
    mtbr member
    Reputation: itsdoable's Avatar
    Join Date
    Jan 2004
    Posts
    1,902
    Sometimes it's the tolerance on the spider.

    There is also some tolerance on the bolt holes, and you can minimize runout by repositioning the chainring (as mentioned in SB's article).

  5. #5
    mtbr member
    Reputation: jetboy23's Avatar
    Join Date
    Jun 2011
    Posts
    1,232
    There is also play with freehubs. I can turn my bike over, free spin the rear tire, and i will watch the chain rise and fall a bit. No rotation of the chainring, cog, or chain. Just tightening and loosening from the freehub on the axle.

  6. #6
    mtbr member
    Reputation: AndrewTO's Avatar
    Join Date
    Mar 2005
    Posts
    3,949
    ^^^ALL of the above.

    The hard part is knowing that just because you spend more money on a product does not mean you actually get a better quality product.
    I ..... need ..... DIRT!!!!!

    ... and cookies.

Members who have read this thread: 0

Posting Permissions

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

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.