Forum home› Road cycling forum› Workshop

Ultegra 6700 maximum cog size

laurentianlaurentian Posts: 2,220
in Workshop
Does anybody know what the maximum cog size for 10sp Ultegra (6700 I think) is? Or where I could find out? Looking to replace the existing 28t to help me on an upcoming hilly ride (I know 28t should be enough but . . .)
Wilier Izoard XP

Posts

  • arlowoodarlowood Posts: 2,554
    edited 15 February
    It's going back a few years but I think I was able to use a 12-30t cassette on my 105 5700 set up. But that was with a long cage rear derailleur. Is your 6700 derailleur short or long cage?
  • laurentianlaurentian Posts: 2,220
    arlowood said:

    It's going back a few years but I think I was able to use a 12-30t cassette on my 105 5700 set up. But that was with a long cage rear derailleur. Is your 6700 derailleur short or long cage?

    Yeah - it's short cage
    Wilier Izoard XP
  • trevor.hall12trevor.hall12 Posts: 294
    You can normally go up 1 from the recommended with a bit of adjustment .Or put on a road link to make it up to 32
  • i.bhamrai.bhamra Posts: 251
    I managed to get a 32 to work with 6800 short cage but not sure how different 6700 was in design. The 32 was not supposed to be able to work but it did, i'd bet you could at least get away with a 30. Are you already running a 34T little ring?
  • drhaggisdrhaggis Posts: 1,049
    Are there any 10sp 11-30 casettes? I thought the 30T sprocket is a novelty of R7000/R8000 11sp groupsets...

    Regardless, if you're on a pro-compact 52-36 chainring, going from 36 to 34T small chainring is very similar to the 28-30T sprocket change. If more help is needed, Praxis and FSA make sub-compact chainrings. Praxis may require their own bottom brackets, but maybe an FSA solution works. I don't know if thesee are 10-speed compatible, though.
  • i.bhamrai.bhamra Posts: 251
    I think the BCD is different on the 6700 cranks so you need a different drive side crank/spider to go 36 to 34. There was a 12-30 6700 cassette don't know about 105 etc...
  • laurentianlaurentian Posts: 2,220
    i.bhamra said:

    I managed to get a 32 to work with 6800 short cage but not sure how different 6700 was in design. The 32 was not supposed to be able to work but it did, i'd bet you could at least get away with a 30. Are you already running a 34T little ring?

    Yes, currently 34T little ring (FSA) .

    Looking at this for the cassette:
    https://www.edinburghbicycle.com/shimano-ultegra-6700-10-speed-cassette?gclid=Cj0KCQiAorKfBhC0ARIsAHDzslvf2jxND3PpQfauNG2vUvLs9Kgg5-vGaRNsO8eb9Ygzg49hmQv7AmMaAuskEALw_wcB
    Wilier Izoard XP
  • dj58dj58 Posts: 2,200
    edited 9 March
    There were two RD 6700 rear derailleurs,

    RD-6700 rated Min 11T Max 28T
    RD-6700-A (30T stamped into the upper outer cage) rated Min 11T, Max 30T.

    Cassettes CS-6700 11-28T, 12-30T CS 4600 12-28T, 12-30T, CS-5700 11-28T 12-27T

    You might be able to get a 32T to work with the -A model, you will need to screw the B-Tension screw IN to gain sufficient clearance between the 32T cog and the guide pulley wheel. I'd try it in a bike stand and make sure you use a correctly sized chain, avoid using the big-big combination.

    10sp 11-32T cassette CS-HG500-10, CS-HG81-10

    Do come back and let us know if you get it to work.
  • rick_chaseyrick_chasey Posts: 66,323 Lives Here
    edited 28 February
    laurentian said:

    Does anybody know what the maximum cog size for 10sp Ultegra (6700 I think) is? Or where I could find out? Looking to replace the existing 28t to help me on an upcoming hilly ride (I know 28t should be enough but . . .)

    I have this exact Ultegra and was told 30-12 was as big as I could go with the standard mech.

    I ran this without problem for 8 years.

    30-11 is not ideal as it doesn’t sit well on the 11 for some reason.
    _
Sign In or Register to comment.