Convert Double to Triple Chainring

phillipjohnson
phillipjohnson Posts: 117
edited May 2011 in The workshop
Hi I have Kona Jake the Snake 2010 but I am cursing the lack of a smaller chainring when I hit big hills (Hartside, Crawleyside Pass etc)...

http://www.evanscycles.com/products/kon ... e-ec021793

It's brilliant for everyday use but the steep hills killed me on a recent C2C.

Is it possible to convert it from a double chainring to a triple and, if so, what's involved and how much will it cost?

Thanks,

Phil

Comments

  • The Rookie
    The Rookie Posts: 27,812
    I have seen an older JtS on a triple so it's possible, what you need depends on what you have!

    Does your crankset have holes to take a small ring, if so you can keep them, if not you'll need a new set, you may need to respace your BB for the inner ring to clear the chain stay (or may not) and your front mech may not reach out far enough (but almost certainly will).

    Really a case of suck it and see!

    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.
  • Thanks for the info. Really appreciated.

    There aren't any holes on the crankset for it so I think I need to start looking for a new one :-(

    At least I know where to start though :-)
  • saladdays
    saladdays Posts: 92
    I'd try a different cassette first. Changing to a triple can be fiddle.

    How about an 11-28 cassette to replace your 12-25 one?

    http://www.chainreactioncycles.com/Models.aspx?ModelID=50454
  • Thanks for the suggestion saladays.

    I haven't done much work on my bike above re-indexing the gears so this stuff is all new to me.

    I think I will leave it for now... like I say I find my bike brilliant for everyday use. I might look at trying that different cassette if I get booked up on another big ride for next year.

    Thanks again guys... I wouldn't have known where to start without your advice.

    Cheers,

    Phil
  • Adding a tripple could prove expensive, a front derailer designed for a double won't work very well, if at all with a tripple. It needs to be deeper. Also you may need a new left hand sti lever if your current one is only indexed for a double. Also you might need a long cage rear mech as looking at your link you only have a short cage at the moment, that probably won't have the capacity to take up all the slack chain if you are using a tripple.

    I'd try the 28-12 cassette first and see if that gets you enough of a lower bottom gear.
    Dolan Preffisio
    2010 Cube Agree SL
  • Buckled_Rims
    Buckled_Rims Posts: 1,648
    I've a Snake as well :lol:

    The basic Jake models had a triple chainset I believe, so yes, you can fit a triple. The 105 front trigger is triple enabled so you don't need the expense of new triggers.

    The main problem is you go through all that expense and hassle, but really a triple is not that much lower then a 12-28 cassette. A quick calc of gear inches shows:

    30T front cog and 25t rear = 31.7"
    36t front cog and 28t rear = 33.9"

    2" difference but you'd probably not notice it. The 30T front and 28t rear triple combo would probably mean you're spinning madly, so that a walker would probably over take you on a road if you were unable to spin fast enough :shock:

    The other option that I might go down in the future is to fit a compact chainset. It'll be slightly lower gearing and far less hassle then a triple.
    CAAD9
    Kona Jake the Snake
    Merlin Malt 4