[MIGHTYMOUSE]

i dont think its a strength thing vs a twistiness thing.

the left rear has the least weight on it in a launch so is the most likely to spin, so you dont want a twisty (smaller dia) axle on that side to slip and send the 'snap' over to the other side beginning the hoppiness oscillation.

thats what i think. or at least this is part of the answer, the reason its still working for this guy is the other part, the part where the axles dont have the same natural frequency so the 'snap' going thru from one side to the other is kinda cancelled.

yep i vote that.