View Full Version : BB90 Question...

10-11-2016, 07:31 AM
Hi all, need some help with trek BB90 BB!
I've messaged a trek rep who is usually quite helpful too, but thought I'd check with the collective wisdom of the paceline forum... :)

In the past, when I bought the bearings from my LBS for my Trek SC9, it came with two bearings, a lipless sleeve, and two rubbery bearing covers. I would install the sleeve, press in bearings, put covers over, then cranks.

This time, when I recently bought a new bearing set from them, all that came in the baggy was a -lipped- sleeve, and the two bearings, nothing else. So I assumed that the lip on this sleeve was meant to act as the bearing cover too. I pressed in the bearings, then slid in the sleeve to both sides, and the lip of it covered the bearings.......was this backwards?? I thought I had it set OK, but then this morning after not using the bike for a week after a race, the cranks would hardly spin.

This is what I got from the LBS:

Thanks for any help!!!

10-11-2016, 07:44 AM
I may be no help, but a friend with a Madone is noticing some roughness in the BB and I offered to help him replace the bearings. It is an Ultegra crank (late 2000s) and we were going to order: http://www.enduroforkseals.com/id468.html . From looking online it appears that one needs to press out the old bearings (using a tool that is like a headset cup remover) and press in the new ones, then stick the red seals on the outside. Am I correct here? What is that sleeve for and does it need to be replaced?

10-11-2016, 07:46 AM
The sleeve is a protective cover for the crank shaft, to keep it away from wires (di2) etc.

Yes, you punch out the bearings and replace by pressing in new. I'm just confused about the order in which to install with the new set I received in the pic above...

10-11-2016, 07:54 AM
The sleeve goes in first, then the bearings, the seals, then cranks.

If you still have the old seals can you reuse them? I'm 99% sure I have at least one of these bbs new if you need; don't have any treks right now. PM me if you want them.

10-11-2016, 07:56 AM
Thanks Doug....nice to know I've been racing on them the wrong way.....grrrr.....

Thank you for the offer, but I'm in Canada, probably almost as cheap for me to buy new than to pay USPS postage to me! :)

I've always wrenched my own bike gear, for 20+ years now, but all these new standards can make things confusing..

10-11-2016, 04:20 PM
OK, so just finished taking the cranks off, etc, and I was a little off in what I thought I had installed...
OK, I did have that sleeve inserted first, correctly.
So two things.... :)
1. I had the bearing covers installed (in below pic). They push right into the center of the bearing, unlike the previous covers I had, which did not push in, rather they were just the red rubbery covers that sat on top. These black plastic ones that push in, I'm not sure if I was supposed to have them there? It made for a tighter fit of the axle going through...

2. My non-drive side bearing had completely seized... Not turning rough, but literally not turning, even if I tried to force it. How does that happen!??! It was raced in the rain a few times this past summer. Normal for these to seize up after a few months if used in weather?

I've installed some replacements, and just used my old red rubber red covers. Hoping for the best...

10-11-2016, 05:00 PM
Yes you were

and yeah, it can happen. outside of the bearing look pretty nasty?