2x chainring combo shifting issues

Cqc
Cqc Posts: 951
edited March 2014 in MTB general
Hi all, going 2x9, wondering if it's possible to have a 38t and 24t combo, or would it be too big a gap so would ruin the shifting so should I go for a 36t and 24t combo, or would it be fine? Thanks

Comments

  • coulddobetter
    coulddobetter Posts: 812
    I run 42 / 27 on a 2 x 10 . A 15 tooth difference . Guess you should be ok.
  • Cqc
    Cqc Posts: 951
    How's the shifting? Bear in mind I will be using a 3x front mech so the shifting will be less slick
  • coulddobetter
    coulddobetter Posts: 812
    Can't compare as have sram x9 direct mount 2x10 mech , and just treated myself to new cranks and xo gripshift . (Very slick , surprised how much better xo is than x9)
    Have you read this ? http://www.bikeradar.com/gear/article/w ... ing-29342/
  • Monty Dog
    Monty Dog Posts: 20,614
    Most 2x front mech capacity is 14 teeth, so should cope with 38/24 - I use 36/22 with little problems
    Make mine an Italian, with Campagnolo on the side..
  • The Rookie
    The Rookie Posts: 27,812
    Cqc wrote:
    How's the shifting? Bear in mind I will be using a 3x front mech so the shifting will be less slick
    May work, may not work at all, you'll have to choose whether to use the inner and mid or mid and outer sections and you may have height restrictions determined by the frame (cage boss positions for example).
    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.
  • Cqc
    Cqc Posts: 951
    All good points, thank you, I think I'll end up going with the ring and bashguard size I can most easily find, will have to check clearance though, thank you.
  • alexthebear
    alexthebear Posts: 349
    Same as Monty here, I use a 3x slx front mech on a 36/22 without issue, only thing is that being direct mount I can't lower the mech so I am dropping chain a fair bit but will be fitting a chain guide to help with this. As for shifting had no problems at all and it's not a hugely clunky change either
    Spesh Camber - Retired
    Spesh Stumpy Evo - Retired
  • Cqc
    Cqc Posts: 951
    Thanks for the help, I'll check out the clearance this weekend
  • The Rookie
    The Rookie Posts: 27,812
    alexthebear wrote:
    I use a 3x slx front mech on a 36/22 without issue, only thing is that being direct mount I can't lower the mech so I am dropping chain a fair bit but will be fitting a chain guide to help with this. r
    You can't fit a chain guide the mech is in the way, besides the mech IS a chain guide, so just get the right one!

    Not sure how 'dropping chain a fair bit'='without issue' - sounds like a bit of an issue.
    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.
  • jimothy78
    jimothy78 Posts: 1,407
    Keep an eye on ebay for one of the 2x9-specific front mechs (SLX FD-M665). I picked one up for £6 including postage a while back. Shifting, clearance and chain retention are all better than they were when i tried using a tripple mech on a double ring system. It's optimised for a 36/22T setup, but I'm sure that if you raised it up a bit, it would also work with 38/24.
  • 97th choice
    97th choice Posts: 2,222
    ^ that's a good shout.
    Too-ra-loo-ra, too-ra-loo-rye, aye

    Giant Trance
    Radon ZR 27.5 Race
    Btwin Alur700
    Merida CX500
  • Cqc
    Cqc Posts: 951
    Got SRAM shifters so may not work though. (although my current mech is deore lx so it might)
  • jimothy78
    jimothy78 Posts: 1,407
    Cqc wrote:
    Got SRAM shifters so may not work though. (although my current mech is deore lx so it might)

    Yeah, for front shifters and mechs SRAM and Shimano are compatible - it's only rear ones that you need to worry about.
  • Cqc
    Cqc Posts: 951
    O really? Never realized that, thanks a lot

Categories