Bike Forums

Bike Forums (https://www.bikeforums.net/forum.php)
-   Singlespeed & Fixed Gear (https://www.bikeforums.net/singlespeed-fixed-gear/)
-   -   Bottom Bracket bearing size? (https://www.bikeforums.net/singlespeed-fixed-gear/113359-bottom-bracket-bearing-size.html)

Mouton 06-11-05 10:18 PM

Bottom Bracket bearing size?
 
I just found a square taper Shimano NJS bottom bracket today at a garage sale (thanks Judah!) The BB didnt come with bearings and so I ask you: Is there a standard for this sort of thing? 1/4"? All the rest of the measurements are in metric (68mmx107mm)so it seems weird that it would be imperial. Anyways thanx.
-alex

F1_Fan 06-11-05 10:26 PM

99.99% chance that they're 1/4" AFAIK, there's no such thing as metric loose ball bearings on bikes. It's just one of those things that never got metricised.

Mouton 06-11-05 10:35 PM

cool thanks. There are usually 11 bearings per side in a BB? that seems high.

jgsjr 06-11-05 10:37 PM

My Dura Ace hubs use 9, 1/4 bearings on each side.

F1_Fan 06-11-05 10:40 PM


Originally Posted by Mouton
cool thanks. There are usually 11 bearings per side in a BB? that seems high.

General rule is a full race minus one. It's been too long since I repacked a loose bearing BB to comment on exact numbers :)

F1_Fan 06-11-05 10:41 PM


Originally Posted by jgsjr
My Dura Ace hubs use 9, 1/4 bearings on each side.

He's asking about a BB.

jgsjr 06-11-05 11:09 PM

Well, a Dura Ace hub is metric like his BB and it uses 1/4 bearings.......
The Dura Ace hub uses 9 bearings on each side and it is a bit smaller than a BB race so 11 bearings do not seem excessive.

I think it is pretty relevant

Mouton 06-11-05 11:34 PM

good point.

Mouton 06-12-05 11:52 PM

For the record:

11 25-grade 1/4" bearings on each side. Piece. Of. Cake.


All times are GMT -6. The time now is 01:02 PM.


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