Compatability betyween Shimano Ultegra and Deore

Phideaux
Phideaux Posts: 87
edited March 2009 in Workshop
Can anyone tell me if the Deore cassette (11-32) from a MTB will fit onto a Ultegra freewheel fitted to an Audax bike and work properly?
Whether you think you can, or whether you think you can't, you're probably right.

Comments

  • maddog 2
    maddog 2 Posts: 8,114
    yes it will but you'll need the mtb mech too - road mechs can't handle 32t sprockets.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • Phideaux
    Phideaux Posts: 87
    Even if I use a long dérailleur with a double chainset?
    Whether you think you can, or whether you think you can't, you're probably right.
  • maddog 2
    maddog 2 Posts: 8,114
    yep.

    It's got nothing to do with cage length - road mechs have a different geometry which means the top jockey is closer to the sprockets.

    Having said that, some people have managed to use 32t sprockets with road mechs but they're the exception rather than the rule. IME 28t is doable but not much more. The top jockey simply rubs the sprocket.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • Phideaux
    Phideaux Posts: 87
    Ah.... now it's starting to make sense. So it may depend on the length of the hanger?

    If this is the case then I might be able to accommodate the necessary change by making (or buying) a slightly longer hanger (it's a bolt-on to the Kenisis Racelight) to give the required clearance?
    Whether you think you can, or whether you think you can't, you're probably right.
  • John.T
    John.T Posts: 3,698
    Hangers are more or less standard so that would not help. Fitting a longer hanger would compromise the gear change on the smaller cogs. The best way is to fit the Deore rear mech as well. The geometry of this is designed for wider ratio cassettes.
    There are one or two bodges that will let you run larger cogs (well up to 30) but as you needed to ask the question you may not have the experience to do these safely and they are all compromises. Getting them wrong usually means a mech in the back wheel so I would not bother.
    My Fleet.
  • Phideaux
    Phideaux Posts: 87
    OK. So it looks as if when I want to swap over to the 11-32 for upland riding I'll need to change over the rear dérailleur as well.

    Better keep my eyes peeled for a nearly new deore then :lol:

    Thanks for the advice. Better a little expense now, than total embuggerance later.
    Whether you think you can, or whether you think you can't, you're probably right.

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