ultegra 6700 with 12-30 cassette

fuzzdog
fuzzdog Posts: 196
edited May 2014 in Workshop
Hello

There are a few threads on here regarding the compatibility of the Ultegra 12-30 cassette with a 6700 rear mech but as far as I can see they are not compleatly conclusive.
I want to get a 12-30 and I have a 6700 mech. I notice on a couple of websites that it is suitable for use with a 6700 A mech. Now my mech just says it's a 6700. no mention of the A. Is this a different version? I have looked at the tech docs and they list the two versions but only give specs for useable cassettes for the 6700 not the A. It says max is 28 for the 6700.

Lots of people on past threads have said they run a 30 without problems but I would like to know if there is a difference between the 6700 and the 6700 A and what the difference is. Is it just the extra capacity for the 30 cassette?

I'm running a 50/34 on the front

In all cases I'm talking short cage versions

Comments

  • dj58
    dj58 Posts: 2,223
    Hello,

    I can't tell you what the difference is between the RD-6700 SS and RD-6700-A SS, I don't know how you identify the difference between the two, and as you say the Shimano pdf files don't explain it either.

    What I can tell you is that I have a 2013 year bike that came with 50/34T compact crankset and RD-6700 SS cage derailleur c/w 12/28T CS-4600 cassette. I swopped the 12/28T cassette for a 12/30T, and did have to adjust the B tension screw to get the correct clearance between the guide pulley and the bigger 30T sprocket.

    What I did notice was that the upper outer cage plate of the derailleur was stamped 30T. I don't know whether that makes it an RD-6700 or RD-6700-A, the combination does however work on my bike.

    Hope this helps. Maybe someone who knows the answer to your question will be along to tell us the answer?
  • shmooster
    shmooster Posts: 335
    A google image search for large images shows the A version has 30T stamped on the top

    A version

    http://www.rosebikes.co.uk/article/shim ... aid:573577

    Non-A version

    http://www.probikeshop.com/shimano-ulte ... 29396.html
  • fuzzdog
    fuzzdog Posts: 196
    Oh yes. I see that.
    So I guess DJ58 you have an A version for 30T. I'm off to check my one now.
    Thanks. That would seem to sort the question once and for all on an official shimano level. Although it does seem a matter for debate as to weather you can push the limits of the 28T version to cope with a 30T cassette. Several people seem to think it's possible.
    Thanks for so sorting that out. Strange the Shimano tech docs don't include these details.

    Thanks
  • fuzzdog
    fuzzdog Posts: 196
    Pleased to say that after wiping away the dirt I see that I also have the T30 version :)

    DJ58 did you find your swap to the 30 from the 28 noticeably beneficial? It's what I intend to do as I am doing the Marmotte in July and having read some grim reports of previous riders experiences that extra couple of teeth might make all the difference.
  • dj58
    dj58 Posts: 2,223
    Hi fuzzdog,

    Yes I did find there was a noticeable difference even though it is only a 2 sprocket difference. This is my first road bike, been on MTB's for the past 27yrs so having to adapt to road bike gearing, I just felt that I need a slightly lower bottom gear for now, so swopping to the 12/30T cassette was the obvious and most economical solution.

    I'm trying to use the 27T sprocket most of the time as I'm getting better/fitter at climbing, though having the 30T does help when I'm flagging at the end of a longish ride. If you have your own tools to do a swop, give it a try and if you aren't particularly bothered about having an Ultegra cassette, the Tiagra one can be had for approx. £16 online.

    Good luck with the Marmotte ride. :wink:
  • buckmulligan
    buckmulligan Posts: 1,031
    You can get the Tiagra one for £13.04 from CRC at the moment with their 10% off components code (CM10). I've just bought one myself.

    Glad to hear going from 28T-30T makes a perceptible difference, I'm coming from a 27T so hopefully should make the alps somewhat more bearable.
  • markynulty
    markynulty Posts: 409
    I have standard ultegra 6700 rear mech on a Trek 5200 frame and have just fitted a 30t for the fred on sunday. Seems to work thank god as dont think 39 25 would have been much fun!
  • fuzzdog
    fuzzdog Posts: 196
    Thanks very much everyone.
    I've just ordered a Tiagra version. Got it for 10.99 at Merlin. Result.

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