The "CH" Series bearings match the hardest ceramic
balls with the hardest available races. This means no soft stainless steel races. The races are
hardened chromium steel, cryogenically treated and polished to make them the best possible match for the Grade 5 ceramic
balls. Ball "grade" is a measure of roundness. The smaller the number, the more perfectly round the ball.
By way of comparison, a Dura-Ace ball bearing is typically a Grade 25.
Upgraded cup seals are also included. The large OD (41mm) silicone seals will fit most mountain
and road cups. The smaller OD (37mm) seals are for certain cups that have seal recesses of a smaller
Uprades these Outboard BB Bearing
Shimano® Hollow Tech II®
Race Face® X-Type®
*The bearings in our BB
cup sets do not use plastic end cap/axle shims, allowing
us to reduce the bearing ID and use
larger balls for greater strength!