This is super interesting topic!
Being former powerlifter (squat, bench, deadlift) i’ve come to respect biomechanics a lot and how individual they can be and how visible or hidden they can be. Limb length is obvious one, but things like where tendon connects to bone or diagonality of muscle fibers in certain muscles such as quads (=more muscle fibers run along the bone more force they generate).
Some people are better at squatting, then deadlifting. It can be obvious, like limb lenghts. Or it might be not, like where tendons connection. There is so much we don’t see under the skin.
In Weightlifting (Snatch and clean&jerk) there are at least three biomechanically stereotypical lifters. One is back/hip dominant, another quad dominant, and final with more balanced. This all reflects their individual joint angles across movement ranges of competive lifts. And the assumption is that no two lifters have 100% identical lifting style once they find the style most optimal for them. For example Russians seem to think that at national level you need to assume that lifter has perfected it’s own particular style of lifting, after that there is not much need to coach the athlete on how to move.
So how this relates to cycling?
So it could be that one person is biomechanically better at producing power at smaller range of pedal stroke. While another needs all the pedal stroke. Maybe one is “hip dominant” and has to be able to kick right from top of pedal stroke while another is more quad dominant and being able to put the pedal down later. Maybe someone has stronger hip flexors and can actually pull the pedal up. Maybe someone has to engage their back and arms alot more to help with pedal stroke than another. It’s such a can-of-worms with endless possibilities.
This is why i’m quite sceptical of any single model trying to explain how pedal revolution engages various muscles and at what degree. Or does it require slow- or fast twitch. There is one podcast (Scientific Triathlon) with Mehdi Kordi, Dutch track cycling coach, who has a lot of interesting things to say about sprint power and muscle-fiber composition. In short it’s not necessarily for track sprinters to be fast twitch dominant, gear ratios and cadence can be manipulated. Which makes cycling quite interesting sport. That podcast has horrible audio-guality and probably leaves alot more questions than answers, but i find it one of those pivotal podcasts i’ve listened to.
As a side note, top powerlifters (ignore the name, it’s about maximal force output) are actually 50-50 with their muscle fiber composition: slow twitch fibers can be just as good at generating force as fast twitch, it’s all about cross sectional size of the fiber. I’m case example of that: World class deadlifter with average vertical jump in general population. My 5sec power is 15w/kg, and i can hit close to it at low cadences (starting from dead stop). There are lanky road cyclists hitting more, but they probably need very specific gear ratio and cadence to do that. They can make up lacking force output with speed, i lack the speed but can make it up with force output (and with way too much muscle for a cyclist).
Cycling is such a interesting sport because you can manipulate gear ratios to get where you are good at. It has all the same questions as strength sports have on how you have to position your body relative to the bike. But you have to think about it from 5sec to 5 hours. I’ve done rowing, kettlebell sports and running, neither of those has provided such a interesting nut to crack than cycling is.
So yeah, i think it’s huge topic which’s surface hasn’t been even scratched.
