SBRcanuck wrote:
Further to my question... if you look at the attached pic of the GXP kit from trek, it looks like only the non-drive side is smaller. But:
1. Why does that non-drive side bearing have what looks like a sleeve attached to the inner side?? And is that proprietary from trek? Most bearings I see don't have that.
2. In this pic, I don't see the extra black spacer/washer that some other sets seem to be sold with?
Thx!
EDIT - OK, read on wheelsmith website, I see the sleeve is a pressed in reducer. So, is that only on the non-drive side, and the drive side still uses a 24?
The SRAM GXP standard requires a 24mm I.D. bearing on the DS and a 22mm I.D. bearing on the NDS. The NDS has the inner race extended about 4mm to the inside. This extended race mates up with the step in GXP crank spindles where they are turned down from 24 to 22mm. This is how the crank spindle is locked in side to side. On Shimano cranks this lash is set with an adjuster. On the SRAM GXP a wave washer is used in conjunction with the stepped spindle.
Some bottom bracket sellers use two 24mm cartridge bearings and then provide a reducer/extender to use on the NDS side of the BB.
Not sure on the kit pieces or what is being sold for spacers. What you have in your graphic and what I posted from the manual earlier are what Trek provides. The metal seal works well for keeping grit out of the NDS side bearing and the BB area in general. BB90 lack of maintenance leads to the bearing seats wearing out in the frame. Trek stopped replacing frames for this and step one is an oversize O.D. bearing. Step 2 is send frame back to Trek for carbon work:(