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

Bottom Bracket Retrofit

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.

Bottom Bracket Retrofit

Old 02-26-21, 08:46 PM
  #1  
1 Lugnut
Senior Member
Thread Starter
 
1 Lugnut's Avatar
 
Join Date: May 2005
Location: S.F. Bay Area
Posts: 575

Bikes: Motobecane Grand Record, Colnago Super, Mondia Super, Mondia Special, Mondia Prestige (for sale 55cm),Titan Star, Titan Exklusiv, Windsor

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 53 Post(s)
Liked 101 Times in 51 Posts
Bottom Bracket Retrofit

Iíve currently installed a Campy 70mm Italian) BB with a 111mm spindle, coupled w/ a mid-90ís Chorus Crank in the bike. Works & shifts as it should.
Iíd like to install an Omas Italian Ti BB (70mm) that has a 114mm spindle. Itís a moveable (sliding) BB w/ 2 adjustable cups.
Will this fit/work w/o issue?
1 Lugnut is offline  
Old 02-26-21, 09:16 PM
  #2  
oldbobcat
Senior Member
 
oldbobcat's Avatar
 
Join Date: Jul 2005
Location: Boulder County, CO
Posts: 3,456

Bikes: '79 Gios, '80 Masi, '06 Felt, early '60s Frejus

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 163 Post(s)
Liked 123 Times in 92 Posts
Apparently Omas uses an ISO taper, but it's going to depend on being able to insert the drive side cup 3 mm deeper into the shell of the frame and still have enough threads showing to put the lock ring on it. Because if you leave the excess spindle on the drive side, you'll just screw up the chain line.

Here's a guy selling one with a 109 mm spindle. https://www.ebay.com/itm/27393195603...f7cbf56bf689d5

But personally, if there's nothing wrong with the Campagnolo unit, I wouldn't change it.
oldbobcat is offline  
Old 02-26-21, 09:30 PM
  #3  
veganbikes
Clark W. Griswold
 
Join Date: Mar 2014
Location: ,location, location
Posts: 10,014

Bikes: Foundry Chilkoot Ti W/Ultegra Di2, Salsa Timberjack Ti, Cinelli Mash Work RandoCross Fun Time Machine, 1x9 XT Parts Hybrid, Co-Motion Cascadia, Specialized Langster, Phil Wood Apple VeloXS Frame (w/DA 7400), R+M Supercharger2 Rohloff, Habanero Ti 26

Mentioned: 42 Post(s)
Tagged: 0 Thread(s)
Quoted: 2905 Post(s)
Liked 2,099 Times in 1,392 Posts
I personally wouldn't change it. If your Campy unit works stick with it. Changing your spindle length will require other adjusting of the front derailleur to accommodate for the new position of the cranks. Yes you could adjust it out and have your NDS crank be farther out and such but why?

I love Ti but replacing a working unit with something that isn't the same dimension wise just because it is made of a cool material is kind of silly.
veganbikes is offline  
Old 02-26-21, 09:31 PM
  #4  
1 Lugnut
Senior Member
Thread Starter
 
1 Lugnut's Avatar
 
Join Date: May 2005
Location: S.F. Bay Area
Posts: 575

Bikes: Motobecane Grand Record, Colnago Super, Mondia Super, Mondia Special, Mondia Prestige (for sale 55cm),Titan Star, Titan Exklusiv, Windsor

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 53 Post(s)
Liked 101 Times in 51 Posts
Originally Posted by oldbobcat View Post
Here's a guy selling one with a 109 mm spindle. https://www.ebay.com/itm/27393195603...f7cbf56bf689d5

But personally, if there's nothing wrong with the Campagnolo unit, I wouldn't change it.
Yup, I hear you...ĎIf it works, leave it aloneí ! Usually not my style though. More like; Ďfix it till itís broke...lol
Iím Trying to knock-off some weight on this one.

Iím familiar w/ the seller of that Omas 109 BB.
We donít exactly meet eye to eye . . . 👀
But, Thx for the suggestion

Last edited by 1 Lugnut; 02-26-21 at 09:38 PM.
1 Lugnut is offline  
Old 02-26-21, 09:42 PM
  #5  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 16,392

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3485 Post(s)
Liked 2,237 Times in 1,444 Posts
Within what each of calls their "reason" BB weight is pretty much a non factor in real life. Besides the small scale reading difference is the stiffness of the spindle factor. For the same OD the Ti will be about 2/3 the stiffness of the steel one. Some riders are smooth enough pedallers so this is no big deal. But if you're a large guy and/or pedal squares perhaps not what with the chain rub increases to be expected. That said I do agree with oldbobcat is regard to the cup/lock ring aspect.
__________________
AndrewRStewart
Andrew R Stewart is offline  
Old 02-27-21, 08:14 AM
  #6  
JohnDThompson 
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Posts: 23,628

Bikes: Several, mostly not name brands.

Mentioned: 141 Post(s)
Tagged: 0 Thread(s)
Quoted: 2996 Post(s)
Liked 2,091 Times in 1,244 Posts
Your 111mm Campagnolo bottom bracket is a symmetrical spindle for C-Record and newer cranks. The 114mm OMAS bottom bracket is probably intended for a preC-Record asymmetrical (Record/Super Record or equivalent) road crank. That both sides of the OMAS unit are adjustable means it's possible it could work, but you may find there is no exposed thread for the drive side lockring.
JohnDThompson is online now  
Likes For JohnDThompson:

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


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.