Singlespeed & Fixed Gear - bottom bracket

i just got this really nice ochsner frame a bit ago, and i now have it all built up except for the bottom bracket. every single one i try and use is too small, so i think i might need a sealed BB. i'm thinking this because where the BB goes, theres like little decorative holes underneath, which would be a dust magnet with a regular non-sealed BB.

so before i go to a shop and waste money, would a sealed BB be a tiny bit bigger than a non-sealed one? is this my problem? or do i have to get special parts that will fit? ive never even seen a sealed bottom bracket, so a little advice on my dillema would be much appreciated.

Too small in what way? Diameter, spindle length, shell size.

Sounds like a job for one of those Eye-tal-yin bottombrackets.

Need to work out what the threading is on the BB.

If its a newer Oschner frame its most likely Italian. But some of these frames are Swiss and may have swiss BB. Other common type would be french and english.

If the BBs are too small sounds like you're trying English BBs in the frame.

See here for some details.
http://www.bikeforums.net/archive/index.php/t-71331

BTW if you bought this cheap of Ebay just recently (blue frame, 54cm < 100 USD) then you will need a Swiss BB. Either a pricey Edco unit or get Phil wood cups for a swiss BB and use the spindle from another BB.

Need to work out what the threading is on the BB.

If its a newer Oschner frame its most likely Italian. But some of these frames are Swiss and may have swiss BB. Other common type would be french and english.

If the BBs are too small sounds like you're trying English BBs in the frame.

See here for some details.
http://www.bikeforums.net/archive/index.php/t-71331

BTW if you bought this cheap of Ebay just recently (blue frame, 54cm < 100 USD) then you will need a Swiss BB. Either a pricey Edco unit or get Phil wood cups for a swiss BB and use the spindle from another BB.


it is blue... but i didnt get it off e-bay. it has ochsner written in white down the tubes and twice on the rear. and a bull painted on the headtube. mabey its the same one? i'll take it to a shop and ask.

thanks for the help everyone... this is my first nice/obscure frame, so it's been confusing to build, with all the strange measurements.

thanks to the archived thread, i now know it's italian.


whoooooo! now i need to find one of those and its finished!

I hate to admit this, but I didn't know there was such a thing as Swiss BB threading...just when I start to think I know a lot about bikes I learn something else from the forum. Thanks!

Sheldon on BB threading (http://www.sheldonbrown.com/gloss_bo-z.html#bottom)