Dura Ace C24 to 11 speed

My gf has some Dura Ace C24s and is currently running a 10 speed group. We now want to upgrade her to Ultegra 11 speed but I am not sure what to do with the wheels. Does she need a new rear hub for 11 speed?

The freehub can be machined to fit an 11 speed cassette. I had an LX 10 speed hub successfully machined to fit 11.

I have a vague recollection of there being an issue with the machining of the DA hub tho. If you’re a member of Bicycle Advice Worldwide (Australian-based despite the name) on Facebook it might be worth asking there as I recall there being a bunch of discussion on there a while ago. There could also be suggestions for who could do the machining.

Many thanks, not a member yet but will try to enter the group. Didn’t know about it.

Some 10s are already 11s compliant and are sold with a spacer behind the cassette
(I have RS81 that came like that)
So first action could be to pull her cassette off and see if there is a shim spacer there.

That was a good hint. There is spacer behind the cassette (at least thats how it looks without taking the cassette off) and my research so far tells me that pretty much all the latest C24 are 9,10 AND 11spd compatible. Still needs to be confirmed but its looking good so far.

dun forget that shimano 10sp cassettes in the better models also come with a thin spacer. So if there’s TWO spacers, cool. If there’s a 1.85mm spacer, cool, if a shimano 10sp cassette and a thin spacer, not cool.

You’ll find out soon enough when you try and install an 11spd cassette and you can’t screw on the cassette retention.

what model hubs are they, quickest way to tell…

If 7900 era - 10 speed only
If 9000 then 10 & 11 speed

If 7900 era you’ll need to machine the freehub like HM says. There is a good thread on Weight weenies forum about this