Tandem Cycling - FSA Mega Exo BB's
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07-26-07, 08:04 AM
FYI: The FSA Mega Exo BB on my front crank was totaled after somewhere far less than 3000 miles and I just found it after a routine disassembly to clean, check, grease, and readjust the BB/eccentric assembly which felt sloppy. The left side bearing fell out of the cup on disassembly indicating great wear on the bearing and/or the races. The BB and spindle were clean and not impacted by any grit. My LBS mechanic confirmed that they have seen repeated early failures on these BB's. A visit to BB reviews at roadbikereview.com also confirmed the problem, with less than kind words for FSA and their BB's.
A similar situation occurred with my wife’s new road bike with Truvativ cranks and BB’s. I immediately sh**-canned them and went to a Shimano Ultegra crank and BB.
Unless FSA can definitively document improvements to their BB designs I would be very hesitant to have anything to do with their BB’s, or their cranks, which can only be used with these BB's.
07-26-07, 10:01 AM
Well THAT's a buzz killer.
The outboeard bearing designs demand accurate facing,so maybe thats could be a factor..??
Facing an eccentric is a challenge tho for the tools.
Do you know if your frame was faced?
07-26-07, 11:22 AM
Do you know if your frame was faced?
Don't know, it's a stock Burley alu frame and eccentric. The problem does suggest that something(s) are seriously out-of-round, or pinched, or can't stand up to the stresses involved. I presume the eccentric was CNC machined to spec. It would take some forensics that I don't have time for and that FSA should have done (or be doing). If there's a bulletin from FSA on this, I'd like to see it and so would my mechanic. He has seen few, if any failures on Shimano and Campy high end BB's, although the new Campy record integrated BB/Crank design has him worried a bit.
The failures alluded to by my LBS mechanic were on his high-end mountain bike, and other road bikes. He has gone to ceramic bearings at +$125 on one of his setups as one final experiment. The failures spoken in roadbikereview.com were all on roadies.
07-27-07, 08:25 AM
We got about 4000 miles on our FSA Mega Exo BB (front) before it failed. We replaced them with the SABB (Self Aligning Bottom Bracket). We're pleased with the results so far, but with only 2000 miles on them it's a bit early to establish their longevity.
07-27-07, 08:31 AM
The FSA stuff is junk. I tried them on both my road bike and cyclocross bikes. The cross bike's b/b siezed after 1 damp ( not wet and muddy...just a few puddles)race.
I replaced both with Shimano Dura-ace with no problems since ( 10k plus miles on the road bike and have done some very muddy and sandy cross races).
The good thing is that external b/b's are pretty universal in sizing(what a concept,huh?), so you can use Shimano b/b cups with just about any crank.
I have had Competitive Cyclist put Phil Wood bearings in the b/b for my cross bike...they spin very freely. We'll see how they hold up when the race season starts in a month.
BTW....do not get sucked into the big ceramic bearing hype. I tried cheaper and the most expensive. They both failed quickly in real world conditions...as well as leaving a hole in the bank account.
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