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  1. #1
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    mismatched crank arm length

    I am probably going to get flamed for this question but can i run mismatched crank arm lengths with minimal disruption? I want to run a set of arms with a nondrive 172.5 and drive 175. The only reason I am considering this is because I have an option to purchase a power meter arm in a mismatched length and am wondering if I will really notice the 0.1" difference in length. Perhaps the reduced mobility of my left hip might actually make the shorter nondrive arm an improvement.

    thoughts brotherS?

  2. #2
    Norðwegr
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    Personally I wouldn't as it could lead to a hip/muscle imbalance. I doubt it's been done before unless it was to make up for different length legs, guess the only way to know for sure is to try it out.

  3. #3
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    Sometimes a 'deal' actually isn't. I wouldn't consider it.

  4. #4
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    Quote Originally Posted by J.B. Weld View Post
    Sometimes a 'deal' actually isn't.
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  5. #5
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    I have 170mm cranks on one bike, 172.5 on another and 175 on a third. I never notice the difference when I switch bikes but having different length cranks on the same bike....throw down and let us know how it works.

  6. #6
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    That's roughly an 1/8" difference. I can't imagine that it will make any difference.

  7. #7
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    1/8" can be enough of a discrepancy between legs to cause one knee or ankle to be constantly sore. Depends on the person.

    We all have a height discrepancy between our legs. If shreddr's new parts reduce his discrepancy, he'll be aok, maybe even experience less pain and more energy. If it increases his discrepancy, he's could be cursing the purchase. Or either direction may have no effect.

    Our saddle and how we straddle it also comes into play. If he moves across the saddle with each stroke, he could be immune to a 1/2" discrepancy, at the expense of wasting a lot of energy to do that moving around in the saddle.
    I will suffer no butt-hurt fools!

  8. #8
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    Kind of Ironic "POWERMETER", don't you think, knowing going in that one leg will be more efficient than the other…with the saddle down, no movement across the saddle; however, one leg will not get the extension and a power stroke, so already getting a smaller percentage of power transmitted to the cranks…maybe just take an insole out of the power stroke leg side…all will be good, doubt it though..the body knows and will show up as some type of pain…knee/hip wear and tear, wouldn't risk it. Just an opinion from one ridder to another…take it as a grain of sand flying off your tire…no Biggy.

  9. #9
    Sir Shreds-A-Lot
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    lol this is great. would you buy two shoes with different height soles? a car with different sized tires?
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  10. #10
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    Quote Originally Posted by obs08 View Post
    lol this is great. would you buy two shoes with different height soles? a car with different sized tires?
    You might, especially the shoes if you have different leg lengths (very common, but rarely addressed!), and dirt track cars are known to often have 4 different size tires at once so it is always situational.

    2.5mm is exactly 1/10th of an inch, go look at a ruler and see how small that is. Maybe a pro on a road or time trial bike might pick this up immediately, maybe not. On a mountain bike which is what I am potentially using it for, and a SS specifically where I will be standing a lot, I am questioning whether this difference will be readily apparent, which is why I asked the question. I can always buy it and try it, and if I think its a problem get the correct drive side length or sell it, no big deal. My bigger question at the moment is whether the power data will represent what I am actually putting out due to my mildly arthritic left hip, and the obvious to me, over compensation by my right leg.

    I may not win the auction so the point may be moot but if I do I will post my results here! Cheers!

  11. #11
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    Why bother asking for opinions when your mind is already made up?

  12. #12
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    Quote Originally Posted by J.B. Weld View Post
    Why bother asking for opinions when your mind is already made up?
    I am gathering data, none of which you have provided, so thanks anyway.

  13. #13
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    Apologies^ I must have misinterpreted your post.

    Quote Originally Posted by shreddr View Post
    thoughts brotherS?

  14. #14
    B.Ike
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    If you were using platform pedals, you could put a thicker one on the shorter arm and make it even....

  15. #15
    STEEL IS REAL
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    You'll end up with lower back, hip, and leg issues if you pedal unequal length crank arms for an extended period.

  16. #16
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    Quote Originally Posted by J.B. Weld View Post
    Apologies^ I must have misinterpreted your post.
    Fair enough brother I actually decided against purchasing it anyway. Happy holidays


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  17. #17
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    Quote Originally Posted by shreddr View Post
    Happy holidays
    Same to you, and everyone else!

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