Ultegra CS-6700 12-30t compatibility

awsm

I currently run an Ultegra 12-25 with a standard double. I have started riding a lot of hills recently and have been looking at cassette options. I noticed Shimano now do an Ultegra 12-30 cassette and I prefer the steps 24-27-30 over 21-24-28 on the 11-28.

I have had a look through the tech docs and read as much as I can find on forums but to be honest it all goes a bit over my head and I'm struggling to figure out whether or not a 12-30T would fit as is or would it require any other changes such as new rear mech?

Tech Docs:
Rear Mech: http://media.canyon.com/download/manual ... 700_EN.pdf
12-30: http://bike.shimano.com/media/techdocs/ ... 799947.pdf

DHA987S

The largest sprocket that mech will take is 28, so an 11-28 is your "largest" option.

The 6700 mech only supports up to 28, but oddly there is a 30 tooth cassette option in the Ultegra range. It "might" work, but I'd rather not risk it.

Cleat Eastwood

Ive an ultegra gs rear mech that took an ultegra 11-28, tried it just this week with a tiagra 12-30 and it works fine - didnt even have to alter the chain length. Dont think an ss would cope with it though.

I'm sure I saw just last week though an ultegra ss mech that was designed to take a 30 tooth cog - i'm just looking for it now, it was about 65 quid if i recall.

petemadoc

Me and a mate went to the alps this summer and he stuck on a tiagra cassatte with a 30 tooth using an ultegra 6700 mech. Worked fine. Climbing Galibier I was very jealous of those 2 extra teeth !!!!

nickellis

Interestingly Shimano Tech Doc state that both the SS and GS cages should only be used with a 28t.

Monty Dog

FWIW the length of the jockey wheel cage has no bearing on the size of big sprocket, it is to do with the distance between the mounting bolt and the top jockey wheel. Shimano road mechs are designed for 28t max but you can often get away with a 30.

awsm

Cleat Eastwood wrote:

Ive an ultegra gs rear mech that took an ultegra 11-28, tried it just this week with a tiagra 12-30 and it works fine - didnt even have to alter the chain length. Dont think an ss would cope with it though.

I'm sure I saw just last week though an ultegra ss mech that was designed to take a 30 tooth cog - i'm just looking for it now, it was about 65 quid if i recall.

There is a new rear mech it's the CS-6700-A-SS/GS or 30+

I made an error in my op I'm actually running a compact with 11-25 on a short cage rear mech :oops:

Would prefer not to go down the the road of replacing rear mech as well though so have been leaning towards the 11-28. Although quite tempted to 'chance' it without the mech but according to the tech docs not oonly does it exceed the 28t max but also the total tooth capacity by one if I'm doing it correctly?;

Max supported: 33
50-34 = 16 & 30-12 = 18, 16+18 = 34

Monty Dog wrote:

FWIW the length of the jockey wheel cage has no bearing on the size of big sprocket, it is to do with the distance between the mounting bolt and the top jockey wheel. Shimano road mechs are designed for 28t max but you can often get away with a 30.

I'm assuming the max was 28t because at the time that was the max they offered in the range. My main concern now is could the short cage take up the extra slack? Or should I just play safe and get an 11-28?

maddog 2

as said, 28t is the max on current road mechs (long or short cage).

Now you can eek out a bit more sometimes by:
- screwing the b-screw in as far as you can (and I've even fitted a longer one in the past).
- some frames have a relatively long mech hanger, which also helps.
- fitting a 10t top jockey
- running the chain shortish

but failing all that, you'd need a 9spd MTB mech, to give you more clearance. Although in practice (3 occasions) I've found this setup overshifts slightly on 10spd, so i've had to adjust the cable routing to compensate. So it's not entirley fit&forget...

#7rider

Like car manufacturers and rev limits Shimano are being a little bit conservative with their limits.

Have been using Tiagra 12-20 cassette (only £20 from Ribble) on Ultegra 6700 with short cage RD. It will need some adjustment but works fine

FransJacques

30t is fine. Been running one on my touring bike for years with a 9sp 7700 DA rear mech, an Ultegra 10sp rear mech and a DA 7800 10sp rear mech.

Leave enough chain.

cakewalk

Just got a brand new ULTEGRA RD-6700-A rear mech.

Stamped it is '30T''

So Shimano have moved to 30T.

greentea

cakewalk wrote:

Just got a brand new ULTEGRA RD-6700-A rear mech.

Stamped it is '30T''

So Shimano have moved to 30T.

Where did you buy it from?

cakewalk

greentea wrote:

cakewalk wrote:

Just got a brand new ULTEGRA RD-6700-A rear mech.

Stamped it is '30T''

So Shimano have moved to 30T.

Where did you buy it from?

Actually I got it for free. How? Well the mech on my almost 2 year old PLANET - X Kaffenback failed. Shipped it back to PLANET-X and they sorted out the free replacement.

The box is labeled as RD6700A G SS D-ATT
IRD6700ASSG

Time to get that 30T Cassette me thinks.

gigster

I`ve very successfully run an ultegra 12-30 cassette with a short cage Ultegra rear mech. It works without complaint & no problem at all with the rear mech. This was on a 10 speed set up but I also have a Miche 12-30 11 speed cassette & again the same setup works on that too. Great for the hills & big climbs of the alps

svetty

Again, have run a 30t cassette on the rear without problems. It does depend on the individual bike - things like hanger length do vary but I'd be surprised if you found it didn't work fine - a slight adjustment to the B-screw is likely the most you'd need to tweak

andcp

gigster wrote:

but I also have a Miche 12-30 11 speed cassette & again the same setup works on that too.

Hi gigster, slightly o/t, but how do you find the Miche 11 speed cassette? does it shift OK? do they wear OK?