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STI Shifters & MTB Mechs

rothers_bikeorothers_bikeo Posts: 225
edited December 2011 in Workshop
Ok remind me, which of the new Shimano MTB rear derailleurs are not compatible with modern 10 speed Shimano STI shifters ?

Looking to combine a rear 11-36 10 speed cassette with an Ultegra 6700 compact double crank for a special project :)

Posts

  • John.TJohn.T Posts: 3,698
    The 10sp XTR ones.
  • Ah thanks, I was thinking of using a Deore XT M780 SGS 10 speed.

    Cheers
  • John.TJohn.T Posts: 3,698
    edited December 2011
    Ah thanks, I was thinking of using a Deore XT M780 SGS 10 speed.
    Cheers
    I didn't know about the XT version but I think it uses the same cable pull as the XTR one. Best to use a 9sp version.
    Edit. That should have read 9sp version. Ooops.
  • nicklousenicklouse Posts: 81,520 Lives Here
    Not happening. 10 spd MTB kit is not compatible with any road kit.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
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  • b16 b3nb16 b3n Posts: 301
    nicklouse wrote:
    Not happening. 10 spd MTB kit is not compatible with any road kit.

    It can happen with Shimano.
    " GET BACK CROC "
  • nicklouse wrote:
    Not happening. 10 spd MTB kit is not compatible with any road kit.

    I know XTR rear derailleurs aren't compatible - different pull ratio, but are you saying the Deore XT M771 10 speed cassettes are wider than road 10 speed cassettes ?
  • John.TJohn.T Posts: 3,698
    No. The cable pull on Shimano 10sp MTB is different from the 9sp and road 10sp. Just use any Shimano 9sp MTB mech. Some come with a shorter cage option that would look better on a road bike.
  • maddog 2maddog 2 Posts: 8,114
    +1

    for 10spd STI you'll need a 9spd MTB mech (which may struggle with a 36 sprocket).

    will 11-34 be enough for you?
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • maddog 2 wrote:
    +1

    for 10spd STI you'll need a 9spd MTB mech (which may struggle with a 36 sprocket).

    will 11-34 be enough for you?
    Yes but I like to experiment :)

    I know all the Road and the MTB 9 speed stuff is done to Shimano's traditional 2:1 pull ratio and their XTR 10 speed MTB stuff is done to a new progressive ratio (is it 1.4 - 1.6 ?) but it's the new 10 speed Deore XT RD-M780 & RD-T780 that have caught my eye. Does it follow the road or XTR system ?

    In fact where is the info on all this, buried deep within the Shimano docs somewhere ?

    Deore XT gets a lot of use on "Touring Bikes" equipped with STI Shifters, has that come to an end with 10 speed Deore ?
  • Got a nice XT 9 speed short cage rear mech here if you need one. Bought in error for my MTB, thought it was long cage. £27.50 posted :)
    Jens says "Shut up legs !! "

    Specialized S-Works SaxoBank SL4 Tarmac Di2
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