So I am swapping some cranks around on bikes. I had a set of 53/39 cranks on a bike I wanted to move to a different one as an upgrade to that bike and put on a compact crankset to the one I was taking off the standard crank. So I picked up a FSA Gossamer crankset off ebay that came with out a BB but I had an extra laying around in my parts bin. When I took off the standard crankset I noticed that the MegaExo BB had a lip around it to fit the crankset in snug. It doesnt use anything for spacers so its a straight easy install. The crankset I was putting in is also a Gossamer but it uses one blue crush washer on the drive side and a wave washer on the non drive. So I attempted to see how it fit with the BB installed and it seemed like the spindle was a tad to short. My guess was the lips around the bearings just wouldnt allow for the space. So I took my other 6000 BB out of the parts bin and it was smooth, I swapped out the BB and reinstalled the crankset. I used the crush washer and wave washer and cranked it down to 38nm as per spec (went on the lighter side). The wave washer wasnt fully compressed like it seemed to be the 1st time around using the other BB but when I looked at two other bikes with wave washer they seemed more roomy.

So are some 6000BB only to be used with some Gossamer cranks and not others? I thought that all MegaExo 6000 BB was compatible with all energy and gossamer cranks and even as per FSA they claim to be. But if one uses a wave washer vs just the 2 crush or no washers then you have to find a different 6000 MegaExo BB?

So the new compact is on the bike with the parts bin BB I had and there is no play in the BB arms but it does feel a bit tight. I think or at least am thinking it will loosen up when it breaks in as the BB was a new take off I had picked up along the way. The 53/39 standard is off the bike and so is the BB that came with it and will be going on my other carbon bike I will be using for racing. So I am not worried about that as I know that is a perfect match.

Just wondering if anyone has run into similar issues with MegaExo 6000 BB's.

http://i.ebayimg.com/00/s/NzUwWDc1MQ==/z/U8IAAOSw1vlUr5ZS/$_58.JPG

http://i.ebayimg.com/00/s/NjAwWDYwMA==/z/EnQAAOSwU9xUPq1N/$_12.JPG

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So while I was posting this I came across that one crankset I took off and bottom bracket can only be used together as it uses the pinch bolt system while the crankset I was installing only uses the cap to torque down the crankarms. So I wonder IF the BB I had in my parts bin and installed is in fact meant for that crankset or if there is a different BB that I need to hunt down.