BB spindle length?
09-13-09 | 05:01 AM
#1
Thread Starter
Pants are for suckaz
Joined: Mar 2007
Posts: 2,578
Likes: 1
From: Mt. Airy, MD
Bikes: Hardtail MTB, Fixed gear, and Commuter bike
BB spindle length?
I have a Motobecane Messenger FG/SS that I spread the rear triangle to wedge a SRAM S-7 internal gear hub into. Since this hub is wider than the stock flip-flopper my chainline isn't straight anymore leading to a lot of chain-dropping. I'm cool with buying a new BB but I'm not sure what spindle length I need. I believe the stocker is a 110mm so I'm guessing I need a 113 or 115mm but I'm not sure? Anyone know how I should approach this?
Thanks in advance.
and an art shot:
Thanks in advance.
and an art shot:
09-13-09 | 05:52 AM
#2
Senior Member
Joined: Jul 2005
Posts: 2,152
Likes: 1
From: Backwoods of Ontario
Measure your chainline at the rear hub. Measure in millimeters.
Measure your chainline at the chain ring.
Calcluate the difference. Add or subtract twice the difference to your current BB spindle length.
Alternately, if the difference is small, you may be able to space the cog, but new BB spindle is the best approach.
https://www.sheldonbrown.com/gloss_ch.html#chainline
Measure your chainline at the chain ring.
Calcluate the difference. Add or subtract twice the difference to your current BB spindle length.
Alternately, if the difference is small, you may be able to space the cog, but new BB spindle is the best approach.
https://www.sheldonbrown.com/gloss_ch.html#chainline
Last edited by Steev; 09-13-09 at 06:33 AM. Reason: Add link to SB's chainline page
09-13-09 | 01:05 PM
#3
Bianchi Goddess
Joined: Apr 2009
Posts: 28,967
Likes: 4,236
From: Shady Pines Retirement Fort Wayne, In
Bikes: Too many to list here check my signature.
Hello I would have the frame alignment checked, to ensure your frame is still straight and your rear triangle is not just offset to the left.
also I think you just solved a problem for me. a coworker bought a bike off ebay but it came broken. he told me it was shimano but I can't find a shimano 7 IGH that has a rod mechanism to shift it. Thanks for the tip
also I think you just solved a problem for me. a coworker bought a bike off ebay but it came broken. he told me it was shimano but I can't find a shimano 7 IGH that has a rod mechanism to shift it. Thanks for the tip
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk
“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk
