Need help mechanics, problems with FSA ceramic bottom bracket

Triathlon Forum
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Based on my experience with an FSA Mega Exo ceramic bottom bracket on my road bike, I decided to get another one for the TT bike which arrived yesterday. I attempted to install it on my time trial bike which already has an FSA SLK crank with a standard Mega Exo bottom bracket and had nothing but problems.

Started out by removing the existing bottom bracket assembly (an FSA SLK standard Mega Exo bottom bracket) and then proceeded to install the red annodized cups of the new ceramic bottom bracket. Obviously both bottom brackets are English threaded, 68x109.5 but I immediately noticed that while threading on the new bearing cups, even though I had not yet reached the portion of the threads with threadlock, the cups were not spinning on as easily as old ones (actually only 4-weeks old). Once the cups were installed/tightened, I inserted the crank/spindle and then attached the non-drive side crank arm without a non-drive side teflon o-ring. I then tightened the cranl bolt to FSA’s torque specification (~35 n-m) and then gave the crank a spin and found that not only did it not turn freely with the ceramic bottom bracket, one of the cups was making a horrible squealing/squeaking noise (been there, done that with the road bike).

I messed with the setup for over an hour trying a variety of things to eliminate the noise eventually uninstalling the ceramic bottom bracket and reinstalling the orginal. I got out the digital caliper and proceeded to compare measurements/dimensions of the parts for the ceramic bottom bracket to those of a standard Mega-Exo bottom bracket and noted that while everything was within about .05mm, the cumulative differences could add up to 1-2mm difference in diameter.

Comments that I have gathered from the net on external bearing bottom brackets advocate insuring that the bottom bracket shell of the frame is perfectly faced but in this case, seems to me the problem is the spindle sleeve or bearing cups for the bottom bracket are too wide and facing the bottom bracket shell will not resolve the problem. It appears that one or both of the bearing cups needs between .05mm-1mm machined off the inside lip in order to reduce the installed diameter so that the crank spindle/crank arm interface does not bind on the bearing cups once installed. Whats interesting is that my K-Force Mega-Exo crankset with a ceramic bottom bracket on my road bike has none of these problems while the the standard SLK Mega-Exo crankset/bottom bracket on my TT bike is also a tad stiffer than I would like. Anyone have similar experiences or any ideas otherwise I will be spending a bit of time on the phone with FSA later today?

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Called FSA - they said suggested installing without inner alloy sleeve and see if that made a difference othewise take it to a bike shop (oiy)!

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Update:

Since I was not having any problems with the standard Mega Exo bottom bracket, earlier this week I decided to press the ceramic bearings out of the red annodized bearing cups from the ceramic bottom bracket assembly and press the ceramic bearings into standard Mega Exo bearing cups. After I removed the crankset from the bike, rather than reinstall the bearing cups only to find the same problem, I did a dry-run to test fit the ‘hybrid’ bottom bracket by simply sliding the bottom bracket onto the crank spindle followed by installing/torquing the non-drive side crankarm bolt but found that the assembly still way to tight.

At this point I again removed the non-drive side crank arm and then the bottom bracket after which I removed the teflon o-ring that is pressed onto the drive side of the crankset after which I reinserted (no teflon o-rings were used) the crank, tightened the non-drive side carnk aarm and guess what - spins like a champ. Realizing that the the problem is a matter of spacing and not the width of the bearing cups of the ceramic bottom bracket, I removed the bearings from the standard bearing cups and then pressed them back into the red annozied bearing cups. After this I installed the ceramic bottom bracket bearing cups/shim back on the bike, lubed the crank spindle and then inserted the spindle (again without o-rings). After installing the non-drive side crank arm and tightening the bolt to correct torque, I found that it spins freely and has no discernable lateral play. Two 40K training rides later and no problems and I am a happy camper.

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Thanks for the update! I think I resolved my FSA non drive side crank issue as well. Thanks for your help in re: the matter. I have also been contemplating the ceramic BB, but they are sold out at the few places I have checked around for.