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 10-30-12, 08:40 PM   #1
MKIV987
Senior Member
Thread Starter
 
Join Date: Jun 2009
Bikes:
Posts: 146
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Headset bearing conundrum

I'm installing a new cross check fork on my cx bike with a ~3-month old Woodman headset. When I first installed the headset on an aluminum fork, there was a bit of a gap between the lower headset cup and the fork crown race but I didn't think it'd be a big deal. Turns out it was enough of a gap that some mud and grime got into it during a particularly messy cx race a few weeks ago.

I removed the old aluminum fork (1" aluminum steer tubes make me nervous) and switched the fork crown race over to the cross check fork. When installing I noticed that there was an even larger gap between the lower cup and the fork crown race this time. I flipped the headset bearing over and the gap was significantly smaller, but when the bearing is "upside-down" I can tell it doesn't seat firmly in the crown race; I can easily tilt it so it doesn't sit level.

I've included pictures of how the bearing looks "right side up" and "upside down" as well as how the fork fits into the frame both ways. Am I missing something?

Attached Images
File Type: png HB-rightside-up.png (82.9 KB, 25 views)
File Type: jpg HB-upside-down.jpg (17.1 KB, 26 views)
File Type: png Headset-fit-rightside-up.png (86.3 KB, 22 views)
File Type: png Headset-fit-upside-down.png (84.4 KB, 21 views)
MKIV987 is offline   Reply With Quote
Old 10-30-12, 09:21 PM   #2
reptilezs
Senior Member
 
Join Date: Sep 2004
Location: boston, ma
Bikes:
Posts: 2,852
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
match the angles to the crown race and cup. generally the way you have it "upside down" is the correct way
reptilezs is offline   Reply With Quote
Old 10-30-12, 09:22 PM   #3
reptilezs
Senior Member
 
Join Date: Sep 2004
Location: boston, ma
Bikes:
Posts: 2,852
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
actually your crown race looks upside down
reptilezs is offline   Reply With Quote
Old 10-30-12, 09:30 PM   #4
tomacropod
ot.net slave
 
Join Date: Feb 2006
Location: Canberra, Australia
Bikes: Salsa mtb * 3, Intense mtb * 1, Abeni SS rd * 1, Salsa road/touring * 2, Trek Damn one * 1, Vintage/projects * many
Posts: 571
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
The "upside down" alignment is right. The chamfer on the bearing has to be the mirror image of the chamfer on the crown race - so the bearing is centralised. The writing is upside down, but as the bearing is also used in the top cup, it's correct half the time. If you have been running the bearing upside down, just check that it hasn't damaged the bearing. You should notice that the whole thing runs much smoother with it the correct way.

edit: Also, your crown race looks upside down as well.

- Joel
tomacropod is offline   Reply With Quote
Old 10-31-12, 06:20 AM   #5
MKIV987
Senior Member
Thread Starter
 
Join Date: Jun 2009
Bikes:
Posts: 146
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by tomacropod View Post
The "upside down" alignment is right. The chamfer on the bearing has to be the mirror image of the chamfer on the crown race - so the bearing is centralised. The writing is upside down, but as the bearing is also used in the top cup, it's correct half the time. If you have been running the bearing upside down, just check that it hasn't damaged the bearing. You should notice that the whole thing runs much smoother with it the correct way.

edit: Also, your crown race looks upside down as well.
Thanks for your input. I should mention that the other bearing looks identical but has a "Top" marking with an arrow pointing up--ostensibly to indicate which side of the bearing goes up. When I install this one upside down the gap disappears as well, even though the "Top" arrow is pointing down towards the fork.

Can you explain to me how I managed to put a fork crown race on upside down? Doesn't it only go on one way? Only one side of it is channeled to hold a bearing.

Thanks everyone.
MKIV987 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 06:08 PM.