Thanks, good info. A few more questions:
So, if a low torso is desired and if the rider has to ride more slack (i.e., uci rules etc.), based on fit parameters, he/she would have to have shorter (relatively) cranks. And, if that same rider wanted the same low torso but he/she is now able to ride more steep (i.e., on a tri bike), based on fit parameters, he/she would be able to use longer (relatively) cranks. Am I getting that generally correct?
Proper crank length would be the one that gives you a reasonable hip angle as you come over the top.
Finally, what would you say is a range for a reasonable hip angle?
Thanks again.
So, if a low torso is desired and if the rider has to ride more slack (i.e., uci rules etc.), based on fit parameters, he/she would have to have shorter (relatively) cranks. And, if that same rider wanted the same low torso but he/she is now able to ride more steep (i.e., on a tri bike), based on fit parameters, he/she would be able to use longer (relatively) cranks. Am I getting that generally correct?
Yes. And ask Dan to tell you the story about designing Marti Ray’s “Desert Princess” bike.
Finally, what would you say is a range for a reasonable hip angle?
I wouldn’t want to specify an angle. Flat vs rounded back. Muscular vs skinny thighs. Lean vs large gut. Flexibility. Reasonable would be something that feels easy to pedal.
Cheers,
Jim
Where did the idea of proportional crank length come from?
It might be completely n=1 but being of longer legs I actually feel better and more stable on a shorter crank, as I feel a bit more locked in.
Just my own findings.
I started my triathlon career 5 years ago on 170 cranks and the next year went to 165 and thought how did I ever survive without these and tried all the way down in 5mm steps to 150 where I felt when I was locked in I was fast and powerful but struggled throughout a race to stay locked in chasing the gear. At 160 I had that how did I ever survive without these feeling, was locked in and the hip flexor issues I would get later in an ironman disappeared. So the last three seasons I have worked on my position with the 160 cranks. I feel more powerful as I’m engaged more degrees with less dead spots in my pedal stroke. I have no science or data but my power over races has been steadily going up and my heart rate and cadence has been coming down now into low 80’s. I’m 5’ 11 1/2" with long legs for my height. Frodeno has gone to 170 this year and he is 6’3" and I imagine he has done a lot of testing. If it feels good then go with it…