I'm pretty sure the Shimano crank will have a smaller spindle, 24mm if I'm not mistaken while the FSA will have 30mm. Someone will tell me if I'm wrong. You may then need a bb adaptor to make the Shimano crank work.

You should have purchased an Ultegra FC-6700 10-speed crankset.

"the FSA will have 30mm"


The picture clearly shows that it doesn't have a 30mm axle.

nah, he's getting a new threaded BB with the shimano crank.

10sp vs 11sp on the front chain rings shouldn't matter. I run a 10sp front 50-34 with 11sp everything else on one of my bikes. I cant imagine it would be a problem in reverse.

This is what I had read. Does this create problems for others?

I'll only bump this once. Feedback seems conflicting. Anyone else have input?

I really appreciate it.

10/11 speed doesn’t matter.

FSA 24mm isn’t always the same as Shimano 24mm. Weird but they aren’t always the same spec. They measure a few thousandths different—sometimes. There have been a few times where I couldn’t use an fsa crank in a Shimano B.B. just too tight. I’d have to mill down the slightly oversized spindle on the fsa crank.

I believe that the OP purchased a Shimano bottom bracket with the Shimano crankset.

Ah—missed that part. I guess just for general info then on Shimano vs fsa. Just make 24mm equal 24.00mm

I was using 10 speed SRAM chainrings on my Quarq and moved it from my 10 speed Force CAAD10 to my 11 speed Ultegra 9r8000) R5. It shifted perfectly fine, but I was getting a little more noise out of the drive train. Not only was it annoying to me, others I rode with commented about it. It wasn't rubbing anything, and happened in both the big and small rings across all gears. Swapped out to Praxis 11 speed rings and the noise instantly was reduced to what I would consider normal/acceptable. Shifting quality remained the same.

I know this is the opposite of what you're doing, but I too believed that the rings didn't matter either way. It sort of mattered in my case.

Thanks for all of the info everyone. Much appreciated!

Just installed this last night a test rode it today. Works beautifully. No issues whatsoever with the 11-speed/10-speed parts. I did also throw on a new Ultegra chain and 105 cassette since mine were worn a bit.

Thanks so much for the information!

Good to know. I just replaced my FSA Gossamer crank on my tri bike with a Shimano Ultegra 6700 crankset I had sitting around (so I could switch my Stages power meter back and forth between my road and tri bike). Only problem is that my crankset is 172.5 mm and my power meter crank arm is 170 mm. I had to use the BB30 adaptor to get the crankset to work, but haven't had any issues. If the difference in length gets annoying I may end up using that eBay link.