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Can I use an 12-30 rear cassette with my current set up

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  • January 2, 2015 at 4:53 pm #22946
    Sensible

    I currently have Ultegra 6700 kit on my bike. I have compact front chainrings 50/34 and a rear cassette 11-28.
    I can’t find any model numbers on the rear deraillier but it is metallic grey on a 2012 bike.

    My chain is in need of replacement and probably need to change the cassette. I have just ordered an Ultegra rear cassette 12-30 and am now having second thoughts as to whether it will fit.

    Having looked at a grey 6700 RD on the net it states the max number of teeth is 33. Now I am not 100% confident about this but if I understand it correctly, 53-34 =16 and 28-11=17, 16+17 =33, which means I am currently on my limits. If I go to a 12-30 then I exceed the number of teeth by one (53-34 =16 and 30-12=18, 16+18 =34)

    HAve any of you used an 12-30 with this set up. Will it work or will I have problems?

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Viewing 15 replies - 1 through 15 (of 22 total)
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  • February 4, 2015 at 3:24 pm #824955
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    Sensible

    The final word on changing to
    The final word on changing to a 12-30 cassette. Yes it works fine with an Ultegra 6700 short cage rear derailleur. Only noticed a slight benefit from my 11-28 but I can spin a little more on those big hills.

    Had my chain come off a couple of times since having the new cassette and new chain but after following this video
    http://www.youtube.com/watch?v=tfBiXgf8JxI
    and adjusted my front derailleur, it would seem that it was miles out. Now adjusted properly it has never shifted so well.

    Thanks guys for your input, it made me go for it, even though Shimano say it shouldn’t work.

    January 21, 2015 at 8:12 pm #824953
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    Simon E

    Thanks for reporting back,
    Thanks for reporting back, it’s good to know it works.

    If it unships the chain again I would adjust the front mech high limit screw (the outer one) See the Shimano 1-page guide:
    https://www.bike-components.de/bedienungsanleitungen/2011/shimano/rennrad/ultegra/fd-6700.2.pdf

    If you subsequently find shifting onto the big ring isn’t as smooth and/or the chain rubs the mech in top gear then reverse the adjustment.

    January 21, 2015 at 5:48 pm #824951
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    Sensible

    Thought I would report back
    Thought I would report back here now that I have had chance to try my new set up.

    Had my new Ultegra 12-30 cassette and Ultegra 6701 directional chain fitted at my local bike store. Got them to service my rear hub at the same time, which apparantly needed a new bearing.

    My RD-6700 short cage derailleur looks at its extremities when on big to big and small to small rings, but I shouldn’t be in that gear at any time.

    Did a 28 mile ride the other day. All shifting seemed smooth and I would have reported it to be trouble free if it hadn’t been for my chain coming off at the 20 mile mark. It came off the outside of the big chainring when shifting up. It went back on easily…but certainly something to watch.

    Don’t know whether it was because I hadn’t been out for a month or because I had put some weight on over Christmas but was really sluggish(slow). I actually didn’t notice the benefit of the 30 over a 28. Neither did I miss my 11 for a 12.

    Will see how it goes. Thanks all for your comments.

    January 14, 2015 at 10:56 am #824949
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    Sensible

    pablo wrote:will work fine on

    pablo wrote:
    will work fine on a short cage no issues. My bike came with this setup for some reason 28 would have been for me at anything below 10%

    Yeah your probably right there. I have been using a 28 for the past two years, but on those really steep hills have felt that I need another gear. Rather than get out of the saddle for those I can hopefully stay seated an spin a little more with a 30. Will see how it goes.

    January 13, 2015 at 9:08 pm #824947
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    pablo

    will work fine on a short
    will work fine on a short cage no issues. My bike came with this setup for some reason 28 would have been for me at anything below 10%

    January 13, 2015 at 6:17 pm #824945
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    Sensible

    Today I had the 12-30 Ultegra
    Today I had the 12-30 Ultegra cassette and 6701 Ultegra directional chain fitted. Also had my rear hub stripped down, serviced and a new rear bearing. Gearing seems to work fine when hung on the wall of my garage. Just need a dry day to test it properly.

    January 5, 2015 at 12:46 pm #824943
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    Anonymous

    The 30’s only there as a
    The 30’s only there as a bail-out gear surely, so you would only really need it when already in the inner ring. (I say this with a 32 on the back of my CX 🙂 )

    January 4, 2015 at 7:57 pm #824941
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    pcaley

    Yes no problem
    Yes no problem

    January 4, 2015 at 5:05 pm #824939
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    bfaz

    As others have said, it’ll
    As others have said, it’ll work fine. I plonked a 12-30 on my 53-39 for Lands End to John O’Groats last summer, and with the tension screw all the way in I had no probs at all with my ultegra short cage rear mech. So much so that the cassette is still on the bike…

    January 4, 2015 at 11:33 am #824937
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    Sensible

    pcaley wrote:I have used a

    pcaley wrote:
    I have used a 12-30 cassette with a 50/34 chainset and short cage rear mech on my Orbea Avant without problems. It is a bit tight when on the big ring front and back, but how often do you ring that ratio? In my case never!

    I get your point. If big ring to big ring is the only problem then I can live with that, because I rarely go into that gear and can easily avoid it if I know its a problem. I presume it can cope with changing up to a 30 which is obviously larger than a 28.

    January 3, 2015 at 9:12 pm #824935
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    pcaley

    I have used a 12-30 cassette
    I have used a 12-30 cassette with a 50/34 chainset and short cage rear mech on my Orbea Avant without problems. It is a bit tight when on the big ring front and back, but how often do you ring that ratio? In my case never!

    January 3, 2015 at 5:51 pm #824933
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    Sensible

    Think I probably have a SS
    Think I probably have a SS and don’t want to go to the expense of a GS. Will have a chat to my local bike chap to see what he thinks. I can alway exchange the 12-30 for a other 11-28.

    My bike is a Giant TCR Advanced which runs a 12-25 as standard, so will have to see if there is room for a 12-30 on an SS….but interesting to hear it has been done successfully.

    January 3, 2015 at 7:01 am #824931
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    CanAmSteve

    Yes – Shimano always
    Yes – Shimano always understates capacity a bit. Put the bike on a workstand and crank in the B-screw until it clears. Shift through all combos and make sure your chain is still long enough to go Large/Large without being screaming tight. Longer cages on RDs handle more chain better

    January 2, 2015 at 11:39 pm #824929
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    LondonDynaslow

    For some reason, Shimano
    For some reason, Shimano always understate capacity. Not only was it fine but I rode up Alpe d’Huez on it.

    January 2, 2015 at 11:30 pm #824927
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    Sensible

    See extract from tech spec
    See extract from tech spec sheet

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