This thread has me fascinated. I was thinking about it as I rode home tonight, pumping away on my MKS Touring pedals that look oh-so-much like those Lyotards.
It seems to me that it as important to know where the load was applied as it is to know how much load was applied. If you have your foot fully and firmly inserted inthe pedal, maybe even strapped in, then your power is applied at the ball of your foot and probably goes into the spindle via the ball bearings (near the root of the shaft).
If you are just getting started or are sloppily pedalling, it is entirely possible your power (force) is going into the spindle via the outer bearings because you are pressing on the outboard part of the pedal - not via the ball of your foot.
The bending moment is going to VERY different for those two cases. I am certain of this because there is absolutely no way that flimsy central sleeve can carry any significant load from the outboard end of the pedal to the inboard bearing - it is too flexible. I wish I had my handbooks here at home to look up the relative stress for equal load applied at the outer versus inner bearings. I would not be at all surprised if it was 10:1, or more.
"Give me a big enough lever and I can move the Earth."