RyFi69

On my road bike, I've got FSA Compact Carbon Cranks 172mm

I want to put ultegra 6750 chainrings (50 and 34 or 36) on it because the rest of my groupset is ultegra, and I'm thinking the pedaling will be a little smoother.
Will they be compatible? I know the BCD of the FSA cranks is 110, and the 6750 should also have the same BCD. Also, where do you guys think I should buy the chainrings from?

I was looking at https://www.jensonusa.com/Shimano-Ult...10mm-Chainring

But it doesn't look like there is a bolt for the cranks??

jimc101

There are a few issues with your plan. Shimano Ultegra chainrings are profiled to match Ultegra cranks (which is why you can't see the bolt, it's underneath), and will look off if used with another brand / model of crankarm, if it even fits. The link you have provided is for 50 & 34t chainrings, 36t chainrings are standard for 6800 cranks (52/36), not 67** series cranks.

The days of using anyones chainrings with an crank are on the way out, the latest Shimano and FSA use proprietary designs (off set 4 bolt), and would expect all other manufactures to have their own designs in future.

FastJake

I have no idea if the 6700 rings will fit. I think they will, but I'm not sure. If nothing else, 6600 rings WILL fit and wont look nearly as goofy on a different crank.

Also, putting different rings on won't make it "pedal smoother" unless the old ones are worn out.

If you want to go full Ultegra I'd just wait until you're FSA bottom bracket wears out (shouldn't take long ) and replace the whole mess then with an Ultegra crank.

fietsbob

you dont need a brand match to work .. just need them in the proper chainline.

as above if you had flat chainrings on the FSA crnk , get another set of Flat chainrings ..


If any disappearance of cross compatibility is going on .. Shimano And Campag are culprits.

ZippyThePinhead

Many sellers are dumping 10s Ultegra Cranks. Competitive Cyclist and Backcountry.com have them for $165 without a BB.

RyFi69

My crank is compact, necessitating the 50 and 34 tooth chainrings. the 50 in 6750 indicates the compact style of crankset.

jimc101

The point was you normally don't run a 36t inner with a 50t outer, rather a 52t outer (not saying you can if you want to though). The 67** series is being replaced by the 68** series, which gives this option from the factory.

HillRider

Unless your FSA shifts very poorly I expect the change of chainrings will have no benefit except to your credit card company. If it does shift poorly, it would probably be just as financially attractive to change the entiire crank and bottom bracket to a Shimano.