Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

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.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 06-19-09, 09:54 AM   #1
arexjay
Senior Member
Thread Starter
 
Join Date: Jul 2008
Bikes:
Posts: 561
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Bottom bracket size: 108mm or 133mm?

I'm building up a Motobecane Fantom Cross Uno frameset. If you buy it complete from bikesdirect, it comes with a 113mm bottom bracket. If I'm putting in my own bottom bracket and crankset (SRAM track w/ Truvativ powerspline), will using a 108mm bottom bracket mess with my chainline too much?
arexjay is offline   Reply With Quote
Old 06-19-09, 10:47 AM   #2
joejack951
Senior Member
 
joejack951's Avatar
 
Join Date: May 2004
Location: Wilmington, DE
Bikes: 1984 Trek 660, 2003 Specialized Hardrock, 2004 LOOK KG386i (RIP), 2005 Iron Horse Warrior Expert, 2009 Pedal Force CX1, 2014 Islabikes CNOC 14 (son's)
Posts: 10,189
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 189 Post(s)
What's the rear spacing on the bike? Which SRAM crankset? The one Powerspline crankset I found recommends either a 113mm or 118mm, presumably to fit either 120mm or 130mm rear spacing.

If you can adjust the position of your cog on the rear wheel, you might be able to get the 108 to work but it may also put the chainrings too close to the chainstays.
joejack951 is offline   Reply With Quote
Old 06-19-09, 10:48 AM   #3
Mondoman
Senior Member
 
Join Date: Apr 2008
Location: A Latvian in Seattle
Bikes:
Posts: 1,020
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
IIRC, each crankset should have a spec for BB length.
Mondoman is offline   Reply With Quote
Old 06-19-09, 11:09 AM   #4
Ex Pres
#39
 
Ex Pres's Avatar
 
Join Date: Dec 2007
Location: the 35223 (AL)
Bikes:
Posts: 6,280
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 23 Post(s)
No (as in it will not mess with your chainline)

correct chainline = matched BB + crank, which is what you are doing.

Last edited by Ex Pres; 06-19-09 at 02:20 PM.
Ex Pres is offline   Reply With Quote
Old 06-19-09, 01:37 PM   #5
Veloraptor
Mtbiker Roadie
 
Veloraptor's Avatar
 
Join Date: Oct 2008
Location: Colorado
Bikes: Two road and two mountain
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Park Tool Website
If you can get crank to spin with 108 without hitting frame ok. If front derailuer shifts only to middle ring instead of small ring then go to the 113.
Veloraptor is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -6. The time now is 03:45 AM.