I went to short cranks long before it was cool--both TT bike and road bike. What I noticed was that my cadence increased without any real effort. It didn't feel any harder, and I wasn't consciously trying to pedal faster. This confused me so I went down the rabbit hole of trying to figure out why.TobinHatesYou wrote: ↑Wed Mar 06, 2024 9:18 pm
I’m not talking about the aerobic effect or the “overall” feel. I’m talking about the force vector that goes into turning the pedals. That MUST increase at the same cadence and gear ratio with smaller cranks, so skeletal and neuromuscular strain he feels at any particular gear ratio and cadence will be higher. So of course you basically must compensate with higher cadence and lower gearing, and in some cases that really throws things off.
What I found in the publish research I could find at the time suggesting that "cadence" isn't really the self-selecting variable here--it's "foot speed". And when the cranks get shorter, foot speed decreases as cadence stays the same. Which is to say, you end up pedaling faster without really trying, because foot speed is what will remain relatively constant. This ends up reducing the peak forces. Peak forces (as measured with an SRM) stayed pretty much the same across crank sizes. So, everything corrected itself without any real effort. It just got rid of the pain in my hip from being folded over and my knee hitting my chest...
I also went to a 50/34 after the swap on my road bike, because like the OP I felt a bit overgeared on hard climbs. However, the 50/11 was actually fine, for the reason stated above. The only time it got uncomfortable was when I got a wheel change in a race and got a wheel with a 12T small cog, and a crazy tail wind. Not good times.