Long cage or medium cage derailleur for 38/24 x 11/36

hard-rider
hard-rider Posts: 460
edited June 2013 in MTB buying advice
Can someone confirm whether I need a long cage or medium cage dérailleur if I run 38/24 front and 11/36 rear.

Also would you recommend I go for the the shadow + mech instead of the normal shadow? The drive train will be all XT. This is to go on a 29er full suspension trail bike with 440cm chainstay length.

Comments

  • The Rookie
    The Rookie Posts: 27,812
    hard-rider wrote:
    Can someone confirm whether I need a long cage or medium cage dérailleur if I run 38/24 front and 11/36 rear.

    Also would you recommend I go for the the shadow + mech instead of the normal shadow? The drive train will be all XT. This is to go on a 29er full suspension trail bike with 440cm chainstay length.
    Need a mech with a capcity of (38-24)+(36-11)=14+25=39 or greater.

    All in the shimano techdocs so go look to save me doing it for you!

    (techdocs.shimano.com)
    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.
  • hard-rider
    hard-rider Posts: 460
    Thanks. I didn't realise the total teeth capacity in the spec. meant you add the differences between the high and low for the two gear sets. So from that I'll need a long cage as a medium cage will only accept 32 teeth total capacity.

    Would the shadow + version be worth it over the normal shadow version?
  • felix.london
    felix.london Posts: 4,067
    I'm a medium cage mech man myself (lighter, less chain-slap, less chance of whacking it on rocks etc). I think the XT GS is 35t capacity so you'd be spot on with that setup
    "Why have that extra tooth if you're not using it?" - Brian Lopes

    Votec V.SX Enduro 'Alpine Thug' 2012/2013 build

    Trek Session 8
  • felix.london
    felix.london Posts: 4,067
    maths has never been my strongpoint :?

    you def need a long cage
    "Why have that extra tooth if you're not using it?" - Brian Lopes

    Votec V.SX Enduro 'Alpine Thug' 2012/2013 build

    Trek Session 8
  • hard-rider
    hard-rider Posts: 460
    Yeah the only thing now is should i go for the shadow+ or normal shadow? Does the shadow+help with reducing chain slap effectively?
  • Chunkers1980
    Chunkers1980 Posts: 8,035
    I'd buy plus. Only down sides are price and more to go wrong.
  • symanoy
    symanoy Posts: 123
    Stated GS capacity is less than its actual capacity. A medium cage should work with that double setup, see here viewtopic.php?t=12915804&p=18252892
    I'd go for GS shadow + least chain slap, best chain tension. Shadow + costs significantly more but people seem to rate them overall.
    Giant Trance X2 Build Sadly since stolen!
    replaced with Giant Trance MKII
  • hard-rider
    hard-rider Posts: 460
    Thanks. After reading that other thread I may just go for the medium cage.
  • supersonic
    supersonic Posts: 82,708
    You need the long cage.
  • felix.london
    felix.london Posts: 4,067
    I would say it's best to stick to manufacturers recommendations - maybe if you're 1 or 2 over capacity but you'll be running 39 on a 35t capacity mech.
    "Why have that extra tooth if you're not using it?" - Brian Lopes

    Votec V.SX Enduro 'Alpine Thug' 2012/2013 build

    Trek Session 8
  • jairaj
    jairaj Posts: 3,009
    Long cage is what you need. But the medium will still work (it does for me). just means when using small - small combination you will have a slack chain as the mech is at full travel and can't take up any more slack.

    If you ride rough trails or many jumps and drops then the "+" feature can come in handy as helps to stabilise the chain and stop you dropping the chain. If you mainly ride on smooth trails and don't have any issues dropping the chain doubt you'd notice much difference between the shadow and the shadow+