Recent content by Alex S

Ah, OK. Well it was just an example of a trained cyclist* performing the same 6-min test on a cycling treadmill (meaning the power demand was controlled and the same for both tests) using both his regular cleated pedals and with flat bed pedals. They measured the rider's blood lactate response...

And yet in performance tests, riders are able to maintain as much aerobically sustainable power using flat bed pedals as they can with cleated pedals. Indeed incremental tests to exhaustion show no difference between such pedal set ups. Here's an example of a performance test comparing flat bed...

Toe clips, pedal cleats etc may enable some amount of pull up, but the reality is that evening out of torque around the pedal stroke does not happen, and will never happen. Hip and knee extensors are far more powerful than than hip and knee flexors. Pedal force studies using riders with pedal...

Then why did you quote it and use that quote to suggest there were large fluctuations in crank rotational velocity? OK, glad to see that you now agree that crank rotational velocity variations are generally pretty small. Yes, that's correct.

I'll let others who understand some basic physics to check the following thought experiment: Scenario: 80kg bike (8kg) + rider (72kg) riding along at a steady state at 36km/h (10m/s) on flat road, pedalling at 90rpm using circular chainrings. Nothing particularly out of the ordinary about that...

What I'm saying is that if you wish to test the torque readings of a crank spider based power meter by comparing it to the known torque applied when hanging an accurately known mass from the pedal spindle of a horizontal crank arm of precisely know length while it's in the forward position...

Hi Mark I'm afraid that you have both misquoted and misunderstood the paper by Hull et al. They did not measure and find such variations in actual crank velocity. What they specifically noted about pedalling with a circular chainring is that crank velocity, when pedalling at a steady cadence...

SRM's website explanation however is incorrect. Once the assumption of constant angular velocity during a pedal stroke is violated, then the resulting power measurement will be based on an uneven weighting of torque signal during the crank rotation. As you rightly point out, the only way to...

Most modern SRMs use 8 strain gauges, SRM Science uses 20. They also mostly use 2 reed switches.

All the chain and chainring do is hold the spider still when a known torque is applied to the spider via the crank arm. The only lever length you need to know is the crank arm length, as that combined with the mass hung from the pedal spindle of a horizontal crank arm tells you the torque being...