The length of crank arms seem to be somewhat problematic when you think about it. As we get older, we are told we should go to shorter crank arms, so we dont have to flex legs and hips so much. But OTOH, and we get older, we lose some strength, and shorter crank arms mean less torque. So what is the consensus here, short or long, for us old guys?
all personal, with your description it sounds like giving in and loss of range of motion if going for shorter crank arms for that reason. Who knows?
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Location: Parañaque, Philippines
A decent bike fit would really do the trick here, there's a lot of factors to consider
Location: Oregon Rainforest
the torque/LEVERAGE increase mentioned earlier also requires added input to utilize...
too long of crank arms increases foot velocity for any given cadence (RPM)... it also ups the STRAIN on Knee and hip joints.
the trick is finding the PROPER CRANK LENGTH for you and your chosen riding style... most older folks aren't looking to win any races in the first twenty feet... BMX cranks are longer for that reason.,.. they Need to get out front or be left behind... most BMX bikes never race, and would be much more fun to ride with a 170 instead of 180 and 185mm cranksets.
personally, i'm now riding a 54cm road frame, and used to ride 56cm...
similarly, i'm now using a 165mm crankset, and wish i'd switched from 170mm a decade ago.
i use a bit higher cadence than most, and the shorter stroke makes that easier.