High Tensile Sprocket Bolts

[Spirator]

Hello, in our rookie season, Breakaway, our robot managed to shear the drive sprocket off the centre wheel. We were using the standard Andymark #10-32 bolts on an 8" Plaction wheel and it was being driven off an Andymark Toughbox with 2 CIM motors.

We're concerned because we want to make sure that a 6WD Plaction set up isn't going to have a repeat and we concerned to the point of buying hi-tensile bolts as replacements.

Out of your own experience and knowledge, what do you think would cause such a break? The bolts holding the sprocket onto the wheel broke, if I recall correctly.