Advertise on Bikeforums.net



User Tag List

Results 1 to 3 of 3
  1. #1
    Senior Member
    Join Date
    Aug 2013
    Location
    Tennessee
    My Bikes
    Breezer Storm Comp 29er
    Posts
    181
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Wheel size chart for BC 16.12 CONFUSION!

    I purchased the Sigma Sport BC 16.12 STS CAD. My LBS programmed my 700x47c tire as wheel size 2268 per a CHART from Sigma Sport. The packaged instructions' CHART has 2250 for this tire size! NOW I'M CONFUSED!. Which should I use?

  2. #2
    Senior Member Bill Kapaun's Avatar
    Join Date
    Feb 2007
    Location
    Mid Willamette Valley, Orygun
    My Bikes
    86 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds.
    Posts
    6,927
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    The one that's more accurate.
    If you can't tell, it doesn't really matter.

  3. #3
    Senior Member
    Join Date
    Dec 2011
    Posts
    153
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    It's less than 1% difference, it really doesn't matter all that much. If you want really accurate, you need to do a weighted rollout test; the numbers in the instruction are just the computer maker's estimate for a typical tire, but tires of same nominal size can differ in reality. Mark spot on ground, get on bike, line up valve stem over mark, roll forward 2 or 3 revolutions, measure the distance and divide and get the mm circumference to use. Alternately if there is some road nearby with mile markers you can just ride it, note discrepancy vs. your current setting, and adjust accordingly. Or measure a ~mile route with google maps or something.
    Last edited by stephtu; 05-24-14 at 04:52 PM.

Posting Permissions

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