Cycling is my first and greatest love , but I suck at it. Slow as molasses.
Hate running but seem to have a knack for it.
Been running for a while and I think I now know why.
"Powered Contractions" of leg muscles when running are shorter compared to cycling and I also read on another post of yours that your running cadence is really high.
So it would seem your legs are better adapted and thus, stronger and more efficient at shorter and faster muscle contractions.
How could you translate this to cycling? One solution is to use shorter crank length and opt for smaller set of gears to allow you to pedal at higher cadence. If end up trying this, you may keep your cassette but since you're getting a new shorter crankset, get one with smaller chain ring.
If you're using 170 mm crank length now, I would suggest getting 150 mm and raising your saddle by 20 mm to compensate. 165 mm crank length won't make a difference. You might feel an improvement with 165 but could be missing out the bigger improvement have you gone smaller.
Don't worry about losing leverage going with shorter crank. You're supposed to use higher cadence and thus, smaller gears with shorter crank, thus maintaining the leverage. If you're worried about maintaining high cadence with shorter cranks, don't. It's actually easy to hold high cadence with short cranks. Even higher than 100 rpm on a long cruise once you get used to it.
I used to have a BMX bike with 150 mm crank. And my only KOM ever was made with that bike. It was due to factors of lightness (the BMX was considerably lighter than my current workhorse) and the fact that I was able to sustain higher power output with shorter crank.
Like yourself, I may be a better runner than a cyclist because I did significantly better with 150mm crank.
