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Old 01-15-13, 07:32 PM   #1
diverguy
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Will Shimano Ultegra swap with FSA MegaExo/Gossamer?

I've been struggling with a clicking/creaking noise on my 2010 Cannondale Synapse 5 Alloy for about two years. It has a MegaExo 6000 English 68 bottom bracket with the external cups and it's running an FSA Gossamer triple crankset.

Long story made very short, shops and private mechanics have tried to fix it to no avail. There is a really long list of what has been tried or ruled out and didn't stop the clicking. Most recently, I put in a new MegaExo 6000 bottom bracket and reinstalled the crankset in the proper sequence and properly torqued each bolt according the specs. The clicking/creaking was noticeable as soon as I left the driveway, maybe 50 feet. That's not enough space to have ruined a bearing with the proper torque and loading.

I'm down to wondering if it could be something in the crankset.

The frame is sized and threaded to take a MegaExo 6000 external cup bottom bracket. Can I swap that out for a Shimano BB6700 and swap the FSA Gossamer for a Shimano Ultegra FC-6700 triple crankset? Logically, the frame is sized and threaded for 68 English so one should be interchangeable with the other, right?

Thanks for any insight.

John
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Old 01-15-13, 07:55 PM   #2
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it should work. measure your current chainline (centerline of the seat post to the middle chainring), and check the specs on the new one... http://techdocs.shimano.com/media/te...9830750016.pdf says a FC-6703 triple has a 45mm nominal chainline when used with the supplied BB. I believe shimano measures from the inner surface of the middle ring.

i note there are two different size adapters for that crank, 68 and 70mm, make sure you get the 68mm.
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Old 01-15-13, 08:01 PM   #3
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Thanks Pierce. Just checked. It's 45mm. Should be good. I appreciate the info and help.
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Old 01-16-13, 05:57 AM   #4
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Loose BB threads? Tried teflon tape?
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Old 01-16-13, 07:15 AM   #5
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Quote:
Originally Posted by Kimmo View Post
Loose BB threads? Tried teflon tape?
Thanks Kimmo. Yes, teflon tape is one of a multitude of things that have already been tried but didn't help. A lot has already been ruled out. Down to the last very few items.
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