XT tripple front mech and double crank

tofu21
tofu21 Posts: 359
edited March 2012 in MTB workshop & tech
Hello,
I've been helping out a friend building his bike.

He's got a M785 40/28 crank and a tripple direct mount front mech.

We couldn't get the front mech shifting right. When on the 36t on the cassette, if the front mech was setup not to catch on 28 ring I wont shift to big ring on the front. If the front mech is setup so it will shift to big ring it catches terribly on the small ring.

There is about a 2mm gap between te big ring and the front mech.

We didn't spend too long playing with it.

Should we be able to get this working?

Comments

  • ricardo_smooth
    ricardo_smooth Posts: 1,281
    yes
  • The Rookie
    The Rookie Posts: 27,812
    Yes, but shouldn't really be using the big ring at the front with the 36T at the back anyway, certainly not shifting up, so does it matter?

    Simon
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • Chunkers1980
    Chunkers1980 Posts: 8,035
    Simon, that's not correct. That's the point of doubles, every gear is usable
  • nicklouse
    nicklouse Posts: 50,675
    Is the mech 10 or 9spd?

    It should be doable but there can be some issues. The direct mount may be causing issues due to positioning.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • tofu21
    tofu21 Posts: 359
    It's 10 speed throughout.

    I am going to try raising the mech a little at a time and see if that makes any difference.

    If he had got a double front mech it would have been a lot easier.
  • nicklouse
    nicklouse Posts: 50,675
    Is the shifter set to 2X mode?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • tofu21
    tofu21 Posts: 359
    nicklouse wrote:
    Is the shifter set to 2X mode?

    Yes.
  • tofu21
    tofu21 Posts: 359
    After a lot of playing about the LBS that he got the front mech from gave up and have replaced it with a double and it's now working seamlessly.

    I know the Ibis Mojo SL-R can be a bit fussy when it comes to front mech/chainset combinations so it looks like the triple mech and double chainset is incompatible config.