When it comes to sealed bearings, I think there are only a few things
that matter, e.g. the dimensions. For example, 6001 hub bearings are
very common, and they are :
28x12x8
meaning, 28 mm outer diameter, 12mm inner diameter, and 8mm wide. If
you can remove one bearing and measure it, the dimensions will allow
you to find a replacement at an online bearing shop. For example, my
mavic hubs came with :
6001-ZRS
6001 = 28x12x8 bearing
Z = metal seal on one side
RS = rubber seal on the other size
although I probably could have bought 6001-2Z or 6001-2RS bearings
(metal on both sides; rubber on both sides) without serious
repercussions.
I have recently learned that there are at least 4 types of replacement
bearings :
- 'normal' bearings, that probably came with your hub, about $5-$10/ea.
- 'high speed' bearings which typically have no-contact seals, $8.
- 'ceramic' bearings which have very special ceramic balls with, $20
some amazing properties such as 4x longer wear and ability to
tolerate no grease for much longer and less friction but at
about 4x the cost.
- 'angular' bearings (
www.philwood.com) which supposedly are , $100
super-low friction and cost a large fortune.
- Don Gillies
San Diego, CA