Crank Length?

TMR
TMR Posts: 3,986
edited September 2010 in Road beginners
Can anyone please tell me if there's a general rule of thumb to determine which crank length one should choose when buying a groupset? I have a choice of 172.5 or 175mm.

I'm 5'11" if that helps :)

Comments

  • Monty Dog
    Monty Dog Posts: 20,614
    Height in cm ~ crank length in mm. More accurately to do with femur length i.e. longer legs = longer cranks. Likewise, those that prefer higher cadences = shorter cranks
    Make mine an Italian, with Campagnolo on the side..
  • sungod
    sungod Posts: 16,522
    my bike - faster than god's and twice as shiny
  • TMR
    TMR Posts: 3,986
    Monty Dog wrote:
    Height in cm ~ crank length in mm. More accurately to do with femur length i.e. longer legs = longer cranks. Likewise, those that prefer higher cadences = shorter cranks

    So as someone 174cm, I should go for 175mm cranks?
  • Monty Dog
    Monty Dog Posts: 20,614
    I can't say for sure, because there are number of factors, but it would be a good place to start.
    Make mine an Italian, with Campagnolo on the side..
  • rake
    rake Posts: 3,204
    sungod wrote:
    so in short the long haul fast cyclist can benfit from longer cranks whereas the indoor track cyclist can benefit from spinning up quicker.. i think its down to leg length. if you have long legs (guess what i do ) you can feel like you're not using you're reach effectively with shorter cranks. higher cadence is possible with short cranks but while the dead spot isnt as large neither is the power stroke. so to sum it all up i havent a clue.i hope this helps. :? im still a 5hit cyclist anyway :wink: .
  • cougie
    cougie Posts: 22,512
    I really don't think it matters too much. I can't tell the difference and I even rode a few months with odd cranks cos one had fractured. Its such a small difference in the scheme of things.
  • Don't worry about it mate. I spoke to a very experienced bike fitter about this once and his opinion was that it really doesn't matter much at all - maybe for pros who need to eek out every ounce of efficiency out of their bikes but for mortals like us just roll with whatever you have.

    He did say that if he really had to advise about it that people of normal to taller height (I guess 5'8" and up) can get away with anything and people that are particularly short might, maybe be better off with shorter cranks.