Compact crank compatability

[farmallguy]

I recently bought a used Colorado III and then discovered this forum, and this is my first post. But the question is about another bike, a Scott CR1 Pro. It has Ultegra FC-6600 53/39 cranks on it and I am contemplating putting compact cranks on it. Will new Ultegra FC-6750 cranks fit? Will I have to change the bottom bracket also(BB30)? Would some other brand fit better?

Thanks

Jack

[oliver1850]

Welcome to the forum. Nice handle, I have 3 Farmalls, plus some other brands you may be able to guess. Your Scott is BB30? Does it have adapters to use threaded Shimano cups now?

[farmallguy]

Gotta love those old machines! I am probably wrong about the bottom bracket being BB30, it is the Ultegra BB from 2008. I have been away from road bikes for a few decades and am learning the new technology.

Jack

[patrick8037]

Scott doesn't do BB30. Their frames come with either threaded bottom brackets or BB86/92.

[oldpotatoe]

I recently bought a used Colorado III and then discovered this forum, and this is my first post. But the question is about another bike, a Scott CR1 Pro. It has Ultegra FC-6600 53/39 cranks on it and I am contemplating putting compact cranks on it. Will new Ultegra FC-6750 cranks fit? Will I have to change the bottom bracket also(BB30)? Would some other brand fit better?

Thanks

Jack

Yep, plug and play. Use the same BB cups that you have. Lower the front derailleur, perhaps shorten the chain, go ride. The 6750 cranks are great cranks as are the 5750. Stay away from sram/truvativ, FSA, IMHO>

[farmallguy]

That's what I was hoping, thanks for the info guys.

Jack

[farmallguy]

So oldpotatoe, or anyone else, will the standard cage 6600 rear der. handle 50/34 chainwheels? I was looking at shimano's site and it said front chainwheel tooth difference 14 teeth or less.Compacts would be 16 teeth, has anyone tried it? I will be using a 12-25 cassette if it matters.

Thanks

Jack

[thwart]

Not old potatoe, just old professor... :D (Fart word not welcome here,,,Serotta_PETE))

I switched out a standard DA crank for a 50/34 compact Ultegra for my brother-in-law, only change was adjusting the FD height and removing one chain link. Normal cage RD worked great with this set-up... 12-25 cassette as well.

[rice rocket]

I don't run the Ultegra 6600, but I do run the 7800 which should operate identically (someone feel free to correct me). I run a 50/34T w/ a 11-28 cassette and it shifts great. It's "out of spec" according to Shimano in cassette size and chainwrap capacity, but it shifts just as well as when I ran 53/39 and a 11-23 cassette.

Oh, and make sure your chain is sized properly (there's only one correct length to hit both the 50T/28T combo and the 34T/11T combo without rubbing).

[oldpotatoe]

So oldpotatoe, or anyone else, will the standard cage 6600 rear der. handle 50/34 chainwheels? I was looking at shimano's site and it said front chainwheel tooth difference 14 teeth or less.Compacts would be 16 teeth, has anyone tried it? I will be using a 12-25 cassette if it matters.

Thanks

Jack

Yes, no need for a compact front derailleur. A standard one will shift fine.