Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

BB Compatibility

Search
Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

BB Compatibility

Thread Tools
 
Search this Thread
 
Old 09-15-11 | 11:56 AM
  #1  
Thread Starter
Junior Member
 
Joined: Sep 2011
Posts: 12
Likes: 0
BB Compatibility

I was looking at the Shimano UN-54 BB on Amazon, and noticed they didn't have a 68x122.5mm option. There is, however, a 68x122mm option, and I was wondering if that was close enough to or is compatible with a 68x122.5mm BB like the one Specialized says my bike has? Of course, 68x122.5 is available in the cheaper Un-26 BB on there.
Sevalecan is offline  
Reply
Old 09-15-11 | 12:13 PM
  #2  
CACycling's Avatar
Senior Member
 
Joined: Feb 2008
Posts: 4,571
Likes: 16
From: Oxnard, CA

Bikes: 2009 Fuji Roubaix RC; 2011 Fuji Cross 2.0; '92 Diamond Back Ascent EX

The .5mm difference is 2/100 of an inch. Assuming the BB is symetrical (important to find out before ordering), that moves your crankset 1/100 of an inch closer to the frame. That will work fine.
CACycling is offline  
Reply
Old 09-15-11 | 12:39 PM
  #3  
Senior Member
 
Joined: Dec 2005
Posts: 7,848
Likes: 4
Probably even a 118 will work fine too. +1 in the symmetry part
ultraman6970 is offline  
Reply
Old 09-15-11 | 02:04 PM
  #4  
Chris_W's Avatar
Likes to Ride Far
15 Anniversary
 
Joined: May 2007
Posts: 2,354
Likes: 15
From: Switzerland

Bikes: road+, gravel, commuter/tourer, tandem, e-cargo, folder

It could even be that the one listed as 122mm is actually 122.5mm. Certainly nothing to worry about.
Chris_W is offline  
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Inpd
Bicycle Mechanics
2
04-27-16 01:28 PM
Cyclist0383
Singlespeed & Fixed Gear
0
06-29-14 04:00 PM
Tavish
Bicycle Mechanics
1
04-09-12 03:04 PM
Mac2131
Bicycle Mechanics
2
02-06-10 01:43 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.