I too think it was strange this has been moved to marketplace alerts... It is certainly a tech thread now. Maybe move it to the modified zone or whatever it is called if it needs moving...
Anyway, back to physics.
I am not 100% sure what he is getting at - is he trying to say the airbag can shock load the arm???
He might be talking about the increase in spring rate when the bellows get to the bottom of the piston (where it flares out). The spring rate increases quite quickly there.
So if you are driving at speed with a full load on and hit a bump that fully compresses one side, you will get a bigger increase in spring rate at the end than you would with coils...
However since landies come with OEM airbags... maybe Simon tried to make them too lightweight...

