11-28 rear cassette with ultegra ??

kr1s
kr1s Posts: 125
edited March 2010 in Workshop
Hi

Im wanting to fit a 10 speed 11 - 28 cassette to my trek madone (existing 10 speed)

Im worried that the clearance may be tight on the 28 cog and upper jockey wheel

Has anybody any advise

Thanks -
Trek Madone 5.2 08
Specialized Tricross
Scott Scale
Twitter @ChrisBedford1

Comments

  • Mister W
    Mister W Posts: 791
    You'll probably have to adjust the b-screw but it should fit okay.
  • kr1s
    kr1s Posts: 125
    thanks alot - il try it then :wink:
    Trek Madone 5.2 08
    Specialized Tricross
    Scott Scale
    Twitter @ChrisBedford1
  • maddog 2
    maddog 2 Posts: 8,114
    yep, b-screw and correct chain length (not too long) and it should be fine
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • kr1s
    kr1s Posts: 125
    Fitted this last night and is sweet :)
    Trek Madone 5.2 08
    Specialized Tricross
    Scott Scale
    Twitter @ChrisBedford1
  • i'm thinking of doing similar on my old road bike which i'm using for touring this summer.
    it has a short cage sora rear mech which shimano says can take a biggest cog of 27T on the cassette.
    is this the same situation you were in 'kris' wanting to fit a casette marginally too big?
    anyone help?
    exercise.png
  • maddog 2
    maddog 2 Posts: 8,114
    officially it is 27t for the older short cage mechs (6700, 7900 are 28t officially) but 28t is usually fine in practice.

    For touring it depends on how much kit you are carrying obviously, but on a compact you could go to 33t ring and 11-28 on the back, which is fairly low.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • kr1s
    kr1s Posts: 125
    The 11 - 28 fits really good with smooth indexing on the ultegra 6700 rear mech.
    Casette is sram courtesy of wiggle - reccomend !
    Trek Madone 5.2 08
    Specialized Tricross
    Scott Scale
    Twitter @ChrisBedford1
  • andrew_s
    andrew_s Posts: 2,511
    With Ultegra, 30T is the point at which the top jockey meets the sprocket. You can usually get it usable with careful fiddling with the B screw and chain length, but this may leave the chain too short for big/big.

    The size of the largest sprocket you can use with a mech is determined by the angle of the parallelogram. Cage length makes no difference. All Shimano road mechs are officially 27T max. For 30T or bigger you'd want to switch to an MTB mech.
  • kr1s
    kr1s Posts: 125
    27 might be the max but it runs sweet with the 28 - should take the sting out of holme moss :)
    Trek Madone 5.2 08
    Specialized Tricross
    Scott Scale
    Twitter @ChrisBedford1