dvdslw

I'm building up a Trek Domane and need a Bottom Bracket. I know the BB90 gets talked down on and Trek finally got rid of it this year but my new frame is a 2019 model so it is what it is. Looking around for a new bearing kit, I find that there's many options like std steel, ceramic, hybrid, angular contact, etc... Looking for recommendations from mechanics out in the field that have actual experience with this bb standard as to what works best and what to stay away from. Looks like installation is similar to the BB30 that was in my Caad10 by using green Loctite on the bearing before pressing it in.

dsbrantjr

One thing that I know is that the advantages of ceramic bearings (high speed and temperature) are wasted on a bike, so save your money.

DOS

Yeah, similar to BB30, no cups, just pressed in. I am not a “mechanic in the field”, just a hobbiest, but recently did a bunch of research so thought I would share. I have only installed on BB30 and recently switched to angular contact enduro bearings. I made the witch based on a couple of recommendations, to include from Enduro reps themselves, that showed angular contact in BB applications achieved more longevity because the handle side load better. There was long discussion in this thread https://www.bikeforums.net/bicycle-m...o-hambini.html. Main thing with AC bearings is that your crankset needs to allow for preload adjustment and one poster made the point that if your preload is maintained by a wavy washer, you should probably use radial bearings.

My decision about AC notwithstanding, lots of compelling arguments were made about just chosing high quality bearings from reliable bearing manufactures (NTN, e.g.). This is the approach advocated by the Hambini guy referenced in above thread.

My take away from research is that BB options that promote their product based on bearings that spin really freely (the so called spin test—see bbinfinite) is that they use very light grease and noncontact seals to reduce drag. I chose against these options for fear of contamination from water and grit would shorten bearing life.

I never considered ceramic because I thought they were overkill for BB applications and also had read that the hard ceramic balls wear out the steel cartridge races quickly. So longevity is an issue.

For retaining fluid, I use loctite 641 but have seen recommendations that with carbon frames you should also use an activator to help with curing.

I found that the folks at Real World Cycling, an Enduro seller, were very responsive to my questions so you might shoot them an email at info@enduroforkseals.com.

Le Mechanic

I've worked as a mechanic for a couple of different Trek dealers since the inception of the BB90 system, so I've experienced installation/servicing/troubleshooting hundreds. In my opinion, the OEM Trek BB's are good. They use the same NSK bearing set-ups that Shimano uses, and an Enduro bearing on the NDS if it's a GXP BB. Wheels MFG angular contact bearings are good as well. I don't use any type of retaining compound unless the bearings push in easily by hand. Just make sure your crank is adjusted correctly (not too tight or loose) and if you're a heavy sweater who rides the trainer, replace the bearings often. That's where I've seen the most damage to carbon frames from corroded, seized up bearings that can damage the frame.

Andrew R Stewart 

Note that Trek has had a lot of issues with the BB bore (where the bearings sit) being a tad oversized, or wears to become oversized. So many complaints that Trek has made available a unique "oversized OD" bearing that will press in where a standard sized bearing will slip in (and out). As you take the BB apart note the ease of removing the OEM bearings and judge whether the OS bearings might be the better fit. Andy

HillRider

Maybe, just maybe the proliferation of bottom bracket "standards" has come to an end. Trek (and Litespeed as an option) going to T47 is a welcome admission that the press-in concept is pretty much a failure. Perhaps T47 will become the new dominant "standard" since it accepts just about every spindle diameter and could even be sleeved down to English threads so common cartridge and external threaded cups could be used.

Andrew R Stewart 

The "press in" designs can and have worked well, in many cases for decades. It's been suggested that the looser tolerances that the industry has allowed, with the move to all carbon construction, are to blame for a lot of the issues riders complain about. Burley Duet tandem had this design back in 1988. Mine got over 20K miles before I moved it on, still with the OEM bearings spinning smooth. I've serviced quite a number of Fishers and Kleins in the 1990s that died mainly from riding through the salt laden Cleveland winters. But all had metal BB shells that were well speced/reamed. A carbon shell is a poor application for a press fit bearing. Andy

HillRider

Yes, they can and have but making them work properly requires better tolerances than the industry now seems to be willing to hold. Also, the proliferation of proprietary shell and bearing diameters and widths, bearing retention types, etc. has made bottom bracket selection confusing and will leave many frames orphans as the industry shakes out. The OP is a victim of this trend.

dvdslw

I don't really feel victimized by anything, I scored a good deal on a frame that just so happens to have the BB90. My last bike had BB30 so I'm familiar with the horror stories associated with both but I've also have learned that a properly prepped and installed bearing with some green loctite will yield quite a long service life without issue. I was inquiring more about what brands, styles, or materials work best?

WizardOfBoz

I used Enduro Angular contact bearings in my Domane. Installed using the recommended PTFE grease, to minimize squeeks and wear. Has lasted a couple of years.

HillRider

Well, I didn't mean "victim" in the sense you were cheated since you know what you need. But you did get caught in the transition as a former "standard" got dropped for a new "standard" and your new frame is instantly obsolete. Sorry for the editorializing and thread drift.

smashndash

I would take the bike to a trusted mechanic and see if the bearings fit tightly enough. Many don’t because the frame requires oversized bearings. If you have that problem, I believe that Hambini sells oversized bearings that he gets by sifting through a large pile of bearings and selecting the biggest ones.

I would certainly loctite the bearings from the start, and not after they start creaking and wallowing out the shell.

cpach

Ceramic is kind of a dumb waste of money. I'd recommend sticking with Shimano cranks if possible--GXP is a somewhat worse design. The standard Trek bearings or Enduro will run fine, higher end bearings by NTN etc will reduce drag a little bit. Angular contact probably will run a bit better, particularly if you're careful adjusting the preload.