11-speed Ultegra di2 or 10-speed Dura-Ace di2?
964cup
Posts: 1,362
Slightly complicated, this.
I have an R3 running 7970 (10-speed) di2. I have a number of other bikes with 10-speed drivetrains, and some investment in DA cassettes. I've just picked up an S5 frame to build as a fast road bike, and need a groupset for it. I'm also going to the Alps in July to climb some of the big cols, so I need a climbing setup on the R3 (please no rule #5 stuff, I know my limitations).
The original plan with the R3 was an 11-28 out back (which is not really supposed to work with 7970, but does) and a 33-tooth inner chainring (ditto). That was before the S5 came up.
The maths goes like this: for about the same money I can either put second-hand di2 7970 on the S5, meaning I can swap wheels between both bikes and have one set of spares etc to carry; or I can buy new Ultegra 6870 di2 11-speed for the R3, with a GS derailleur and an 11-32 cassette if I'm really feeling wimpy, and swap the 7970 onto the S5. It means all sorts of fannying about, and returning various bits and/or selling them, but it washes out roughly even.
Which would you do?
I have an R3 running 7970 (10-speed) di2. I have a number of other bikes with 10-speed drivetrains, and some investment in DA cassettes. I've just picked up an S5 frame to build as a fast road bike, and need a groupset for it. I'm also going to the Alps in July to climb some of the big cols, so I need a climbing setup on the R3 (please no rule #5 stuff, I know my limitations).
The original plan with the R3 was an 11-28 out back (which is not really supposed to work with 7970, but does) and a 33-tooth inner chainring (ditto). That was before the S5 came up.
The maths goes like this: for about the same money I can either put second-hand di2 7970 on the S5, meaning I can swap wheels between both bikes and have one set of spares etc to carry; or I can buy new Ultegra 6870 di2 11-speed for the R3, with a GS derailleur and an 11-32 cassette if I'm really feeling wimpy, and swap the 7970 onto the S5. It means all sorts of fannying about, and returning various bits and/or selling them, but it washes out roughly even.
Which would you do?
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Comments
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6870 no question. I have 7970 on my TT bike, but as e-tube didn't start until 6770 there is no chance of upgrading. With 6870 you can update the firmware and swap between other Di2 components (except for 7970) so you're future-proofing yourself.English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg0
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Yes, I thought that would be the verdict. Why am I hesitating?
My PowerTap wheelset is 10-speed, so I'll need to change the freehub, and change the cassette every time I switch it between bikes. Or not switch it between bikes - it's laced to Cosmic Carbones, so perhaps I just accept that the R3 is climbing and windy days only, and the S5 is for RPR laps and fast groups and never the twain shall meet.
I've got three 10-speed DA cassettes, including the as-yet unused 11-28 (and several Ultegra cassettes). There's always the classifieds, I guess.
My other road bikes are all Ultegra 6700, running DA7901 chains, so I only have to carry 10-speed spare links and pins, and my spare chain will fit any of them, and they can all use the same wheels and cassettes.
I'll have to do a complete strip on the R3, and I'll still end up needing an internal 7970 cable set for the S5 and short mount, and a BB30 to GXP converter for the R3; this assumes I move the Rotor chainset from the R3 to the S5 and use the Ultegra chainset that will come with a full groupset. It also means sticking with compact on the S5 (I was going to go 52/36) unless I buy another yet set of chainrings.
Bah. Perhaps I should just build the S5 with a mechanical Ultegra 6700 groupset I have spare and wait 'till I can afford to go 11-speed across both bikes.0 -
Or you could get 6870 and run a 6770 rear mech...English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg0
