JimVG

Hello,

New to this forum. Please advise.

Are there any inherent issues/concerns with the following combination?
Current drivetrain:
Shimano Dura Ace 7900 10-speed crankset. 39/53 – 175mm
Shimano Dura Ace 7900 10-speed 11x28T cassette.

Intended upgrade:
Shimano Ultegra FC-R8000 11-speed crankset. 46/36 – 175mm
Sram PG-1070 10-speed 11-32T cassette.

What new chain would work best with this combination?

Thanks for your time and consideration.

datlas 

I suspect it will work ok with a 10 speed Shimano chain. If your RD has a short cage it may not like the larger 32t cassette in back.

JimVG

Thanks for the reply!

I believe that the 11-30 cassette will work with a standard cage derailleur, but 32 will require a medium cage derailleur as you have mentioned.

Any ideas on the best option?

datlas 

It would be helpful if you told us every component of your drivetrain: RD/FD/Shifters.

You might be able to finesse the 32t with what you have, although cross-chaining may be a problem. See what others in the collective suggest as well.

JimVG

Sorry about inadequate information. The bike is a 2008 Cervelo R3. The entire drivetrain is 2008 Shimano 10-speed Dura Ace 7900. 11-28 cassette & 39/53 crankset. Wheelset is 2009 Mavic R-SYS SSC.

datlas 

I suspect it will work, but that said you may have better functioning if you got a 10 speed Shimano crank rather than an 11 speed. You can likely find them on ScamBay at a reasonable price.

Bigbus

You do realize you're going to lose your top end with that gearing combination? Unless you're a spinning fool, of course.

JimVG

Thanks again for the reply. I have located a new, unused complete Ultegra 6800 11-speed groupset with 11-32 cassette and 34/50 crankset. Very reasonable price. May be a better option for a few more dollars.

JimVG

Regarding top end.....yes that is a serious concern. We do a lot of climbing here. This is the reason that I think the above listed Ultegra 6800 groupset might be a better option for me. Thanks for the comment.

deacon mark

If you pass on the new 6800 let me know I would love to have it. And yes if I were you given a bike I like I would upgrade to R7000. Then you get it all go for the 11-34 cassette.

Canker

I run a 46/30 crank on my road bike that does double duty as a gravel bike. How much time on a typical ride do you spend pedaling at over 30mph? It is a lot less than I spend pedaling at 8mph climbing steep hills that is for sure lol. Anyway if I were doing it today I'd go with a GRX crank with 48/31 gearing. That option wasn't available at the time I made the switch. Yeah you need a new FD to go along with it but those are cheap.