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 01-19-06, 05:03 PM   #1
beat_pedalr
all about the rhythm
Thread Starter
 
Join Date: Apr 2005
Location: chicago-land area
Bikes: too many...
Posts: 61
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Help Removing an Eccentric BB

The bottom bracket I am trying to take out is on a Trek Tandem. It appears to be the same BB found on Trek's Soho model bicycle.

The bottom bracket looks like this....

I have removed the bottom bracket spindel and bearing case. The only thing left in the frame is the eccentric BB shell. I loosened/removed the main bolt but now I don't know what to do. I tried to hammer it out with a rubber mallet without success. The drive side of the shell has two hex head indentations but they don't seem to do anything. can anyone help me out with this problem?

Thanks in advace....
beat_pedalr is offline   Reply With Quote
Old 01-19-06, 05:23 PM   #2
Rev.Chuck
The Red Lantern
 
Rev.Chuck's Avatar
 
Join Date: Apr 2003
Location: Raleigh NC
Bikes:
Posts: 5,965
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I believe that one is in two halfs. after you remove the bolt you need to stick a punch through the BB hole and tap the first half out and then you should be able to get to the other side easy.
The hex holes are for allen wrenches so you can adjust your chain tension by rotating the eccentric. For that matter, they might rotate right out if you stick and allen in it and just turn it.
__________________
Are you a registered member? Why not? click here to register. Its free, and only takes 27 seconds!
Help out the forums, abide by our community guidelines.

I am in the woods and I have gone crazy.
Rev.Chuck is offline   Reply With Quote
Old 01-19-06, 09:11 PM   #3
LWaB
Senior Member
 
Join Date: Dec 2005
Location: Auld Blighty
Bikes: Early Cannondale tandem, '99 S&S Frezoni Audax, '65 Moulton Stowaway, '52 Claud Butler, TSR30, Brompton
Posts: 2,240
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The eccentric is in two parts, wedging like a quill stem. You can insert the bolt again, leaving it a couple of turns loose, giving the bolt head a tap with a mallet, everything should slide out.
LWaB is offline   Reply With Quote
Old 01-19-06, 10:32 PM   #4
Sheldon Brown
Gone, but not forgotten
 
Sheldon Brown's Avatar
 
Join Date: Jul 2002
Location: Newtonville, Massachusetts
Bikes: See: http://sheldonbrown.org/bicycles
Posts: 2,301
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by beat_pedalr
The bottom bracket I am trying to take out is on a Trek Tandem. It appears to be the same BB found on Trek's Soho model bicycle.

The bottom bracket looks like this....

I have removed the bottom bracket spindel and bearing case. The only thing left in the frame is the eccentric BB shell. I loosened/removed the main bolt but now I don't know what to do. I tried to hammer it out with a rubber mallet without success. The drive side of the shell has two hex head indentations but they don't seem to do anything. can anyone help me out with this problem?
See: http://sheldonbrown.com/synchain.html

Sheldon "Eccentric" Brown
Sheldon Brown 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 01:38 AM.