Ultegra 6600/6700 compatibility question

[Tonger]

All,

I have searched here and elsewhere but have been unable to find the answer to my question. I have a 6600 group that I want to run a compact crank but couldn't find a 6650-S so I bought a used 6750 after reading (and hoping) that it should work.

I would appreciate it very much if someone could answer a couple of questions for me.

1. Can I run my 6600 bottom bracket with the 6750 crank, or do I need to find a 6700 bottom bracket too?
2. I have read that the 6750 will work with the 6600 group as long as I get a 6700 10s chain. Can anyone please confirm this for me?
3. Any other tips or hints?

Thanks so much!

[AndrewS]

I'm not sure about the BB compatibility, so I'll leave that to someone else.

You don't need super specific parts, like chains, for Shimano, SRAM, Microshift drivetrains. As long as it is a 10 speed compatible part, you're fine. Ultegra shifter, 105 rear derailleur, DA front derailleur, FSA 9/10 speed crank, SRAM cassette and KMC chain will work exactly as well as a 100% 6700 bike. You can't mix SRAM and Shimano shifter/derailleur combos - SRAM shifter/derailleurs won't work with anything else.

That said, there are varying opinions on how long various brand chains or cassettes last, but that's a different issue from compatibility. Personally, I don't like Shimano's pin system, so I use different brand chains.

[rice rocket]

It's the same bottom bracket, but a DA7900 BB is only $30, they're almost throwaways at this point. They claim improved seals over the 7800, if that matters to you at all.

[dave thompson]

All,

I have searched here and elsewhere but have been unable to find the answer to my question. I have a 6600 group that I want to run a compact crank but couldn't find a 6650-S so I bought a used 6750 after reading (and hoping) that it should work.

I would appreciate it very much if someone could answer a couple of questions for me.

1. Can I run my 6600 bottom bracket with the 6750 crank, or do I need to find a 6700 bottom bracket too?
2. I have read that the 6750 will work with the 6600 group as long as I get a 6700 10s chain. Can anyone please confirm this for me?
3. Any other tips or hints?

Thanks so much!
1. Your 6600 bottom bracket will be perfect with the 6750 crank.
2. The 6600 chain will work well with the 6750 crank, the 6700 chain will work better.
3. The 6750 crank install and use are identical to the 6600 so no issues. If you use a 6700 front derailleur, your front shifting will be greatly improved.

6700 components are backwards compatible with all Shimano 10-speed components (with the exception of some 7900 components). So it's easy to mix and match your gear.

[AFS]

6700 components are backwards compatible with all Shimano 10-speed components (with the exception of some 7900 components). So it's easy to mix and match your gear.
Which 7900 components don't mix well with 6700?

[dave thompson]

Which 7900 components don't mix well with 6700?
The 7900 front derailleur has to be used with 7900 shifters. The front shifter has different pull ratio than other Shimano shifters and it's companion front derailleur is matched to that.

According to Shimano (I don't know this from experience) the 7900 brakes will work with other than 7900 shifters but will give "B" performance.

[Tonger]

Thanks so much y'all, I really appreciate you sharing your collective expertise!

:beer:

[oldpotatoe]

All,

I have searched here and elsewhere but have been unable to find the answer to my question. I have a 6600 group that I want to run a compact crank but couldn't find a 6650-S so I bought a used 6750 after reading (and hoping) that it should work.

I would appreciate it very much if someone could answer a couple of questions for me.

1. Can I run my 6600 bottom bracket with the 6750 crank, or do I need to find a 6700 bottom bracket too?
2. I have read that the 6750 will work with the 6600 group as long as I get a 6700 10s chain. Can anyone please confirm this for me?
3. Any other tips or hints?

Thanks so much!

1)-yes, no...either BB will work with either crank(DA and 105 as well).
2)Not true, no need to get a 6700 chain. Use any 10s chain, whether it be shimano or another manufacturer.
3)Install and go ride, 6750 nice crank.

[socalspeedsk8r]

I think that with Shimano you can mix any of the 10-speed set-ups to work but the reality is that mixing them creates less than ideal performance. The 6700 chain/cassette works noticeably better with the 6750 crank than mixing it with 6600. If you look closely at the 6700 bottom bracket seals you will notice an very small extra lip or step in the seal and different than the 6600. I had an issue when I tried to use a 6700 bottom bracket with a 6600 crank.

Scott