i have a Crank brothers cobalt wheel set and the non drive side hub bearing is siezed ,now i have had this happen before so i want to replace the bearings sets.My question is are all rear hub bearing the same size (as with skate boards in lines and scooters?)or do different brands use different sizes? Hope is near by and i might pop some hope ones in if they fit ,axle is 135 9mm if it makes a difference

Many are different.

Have a look on ebay for Katec,,,

Kaesae has an interesting rep on here but the bearing kits he sells are very good indeed. He is a helpful chap so if you explain what your after, he may have a solution for you…

Bearing sizes for hubs vary by manufacturer, model, variations in design & sizes, axles etc. Though some are more common than others.

The CB bearings are listed here. Note I can’t say that this is correct for all the latest CB wheels as CB have removed this from their web site, so I’ve linked to the archive version…

http://web.archive.org/web/20140713034829/http://www.crankbrothers.com/support/product_documentation/instructions_cobalt_wheel.pdf

I *think* Cobalt and Iodine rear hub bearings are the same (front are not though). 25x37x7 bearings, aka 6805 or go for 6805 2RS (or 6805 LLB) for the double rubber seal. Enduro branded bearings I think are the ones I pulled out of my Iodine hub, but not certain. The freehub bearings are 17x28x7 (e.g. Enduro MR 17287).

And yeah, Katec does them all. Though I got the 6805-2RS from Simply Bearings as much cheaper. I got the freehub ones from Katec in the end as not many places do that size.