I've got a Gossamer MegaExo triple right now and was thinking of swapping to an Ultegra 6600 double. The new 6600 bottom brackets look similar to MegaExo, but are they compatible?

Thanks.

Having installed both, I can say with confidence that they certainly appear to be compatible. But, I haven't actually swapped them. Fortunately, the 6600 Ultegra crank is sold seperate from the BB (unlike the MegaExo cranks), so you can actually try it and see without having to purchase the Shimano BB.

55/Rad

Thanks. Am I going to need to do anything to the BB to take it from triple to double?

Same dimensions. Just did the opposite combo on a customer's bike 2 days ago (FSA Gossamer compact double with Ultegra BB). And the double and triple use the exact same BB.

Great info. Thanks again.

"While this is the BB that comes standard with all of FSA's cranksets that come with an integrated BB spindle, it's also compatible with Shimano Dura-Ace 10 and Ultegra 10 cranksets. It is not compatible with any crankset that does not come with an integrated BB spindle. Available in both English and Italian threading."

- From competitive cyclist.

The more I look at it, the compact/11-23 cassete combo is looking tasty. Of course, if I end up with a Gossamer compact, I don't really get to save on the whole not buying a BB aspect.

You might wanna wait a month or two for the Shimano compact double, it's Ultegra grade and if it's anything like the standard Ultegra double shifting will be a lot crisper and cleaner than FSA's. Plus, Shimano engineered their compact double to be used with a standard front derailleur, so even though the cranks will be more expensive, you're saving on the f/d. And since you already have a Mega EXO BB installed, you don't have to buy that with the Shimano cranks.