Singlespeed & Fixed Gear - Bottom Bracket bearing size?

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Mouton
06-11-05, 10:18 PM
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
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
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.