Ultegra 6800 GS or new R8000 GS RD on a 6800 setup?

daniel_b

Morning all,

going to try for the Fred Whitton next year, and as my smallest front cog is a 36, which suits me, I would like to have the option to run an 11-32 OR perhaps even an 11-34 on the back, for the 33% parts.

6800 GS RD seems to be thin on the ground these days (Unless anyone has seen any?) and the new R8000 GS can already be had for circa £50.

Any reason why the R8000 would cause any issues\complications with my existing 6800 set up?

If it makes any difference, the likelihood is it will be running an R8000 cassette, KMC chain, but the rest will be stock 6800 - ok, well apart from an absolute black 36T inner on the crankset (yet to be fitted)

In my brief bit of reading, I have noted that the R8000 is apparently more accomodating of larger cassettes?

Thanks

super_davo

You can run an R8000 mech on an otherwise 6800 set up. The R8000 mech is rated to go to 30T whereas the equivalent 6800 is rated to 28. However Shimano are always very conservative on ratings so depending on your set up you should be able to go to a 32 on the R8000. If you wanted a 34, then I would go for a medium cage. If doesn't matter what generation, you can even go 105.

In terms of the old Vs new mechs... The new mechs have "shadow" tech which basically mean they set the mech much further forward to wrap around the chain.
This is supposed to give engagement and shifting advantages. The disadvantage of that is it can be harder to take the wheel on and off. But not massively on either side.

If I were you... I would go for an R8000 and an 11-32. Then you have the newer mech all the time, plus 11-32 cassettes are available in 105 (which will be plenty good enough for the job).

StillGoing

super_davo wrote:

You can run an R8000 mech on an otherwise 6800 set up. The R8000 mech is rated to go to 30T whereas the equivalent 6800 is rated to 28. However Shimano are always very conservative on ratings so depending on your set up you should be able to go to a 32 on the R8000. If you wanted a 34, then I would go for a medium cage. If doesn't matter what generation, you can even go 105.

In terms of the old Vs new mechs... The new mechs have "shadow" tech which basically mean they set the mech much further forward to wrap around the chain.
This is supposed to give engagement and shifting advantages. The disadvantage of that is it can be harder to take the wheel on and off. But not massively on either side.

If I were you... I would go for an R8000 and an 11-32. Then you have the newer mech all the time, plus 11-32 cassettes are available in 105 (which will be plenty good enough for the job).

The R8000 GS has been run with a 40" biggest sprocket.

super_davo

Sorry, to clarify I was talking about an R8000 short cage not medium. Just changing to the newer gen short cage should give enough extra for a 32 - if you're also changing to a medium then fill your boots and get whatever cassette you want.

boblo

If it's just for the Whitton, get a 105 5800 GS and an 11-32. I did it last year on that combo and was fine. I usually use R8000 on that bike.