Gearing post?- Mtbr.com
Results 1 to 7 of 7

Thread: Gearing post?

  1. #1
    mtbr member
    Reputation:
    Join Date
    May 2012
    Posts
    12

    Gearing post?

    There used to be a really good post on gearing (e.g. the equivalent gear ratios on 26" and 29er bikes, for a given chainring) under SS FAQ's but it seems to have gone.

    Anyone know where I can find something similar on the gearing formula (searched but no luck).

  2. #2
    Stateline Falls, Watauga
    Reputation: JeffL's Avatar
    Join Date
    Jan 2009
    Posts
    238
    32:16 == 32:18

    That's all you really need to know ;-)

    You can use the gain ratio formula to calculate the equivalent gear for the combinations you're interested in...
    Gain Ratios--A New Way to Designate Bicycle Gears
    It never gets easier, you just go faster. -Greg LeMond
    I'm not as fast as I think I am. -JeffL

  3. #3
    Stateline Falls, Watauga
    Reputation: JeffL's Avatar
    Join Date
    Jan 2009
    Posts
    238
    So, starting with the gain ratio formula, and assuming that you will use the same crank arm length and the same chainring size (as you stated) on both bikes, then you can write an equivalent expression, do some algebra, and come up with a pretty simple formula to calculate the equivalent cogs:

    Cog(29er) = 29/26 x Cog(26er)

    or

    Cog(26er) = 26/29 x Cog(29er)

    Example - the 29er equivalent for a 32:16 26er gear is:
    Cog(29er) = 1.115 x 16 = 17.85 (is close to 18)
    It never gets easier, you just go faster. -Greg LeMond
    I'm not as fast as I think I am. -JeffL

  4. #4
    CB2
    CB2 is offline
    Jam Econo
    Reputation: CB2's Avatar
    Join Date
    May 2006
    Posts
    4,214

  5. #5
    mtbr member
    Reputation:
    Join Date
    Mar 2012
    Posts
    42

  6. #6
    MTB NOLA
    Reputation: vudu's Avatar
    Join Date
    Mar 2008
    Posts
    243

  7. #7
    Bro Mountainbiker
    Reputation: Sheepo5669's Avatar
    Join Date
    May 2010
    Posts
    3,583
    Raised in a Chicken-Coop by Chickens

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.