I’ve been running a F-125 Laydown gearbox kart since 1993. I will not run without a sprag, period. The safety factor is huge, the performance advantage is Impressive, and if you stick a motor the damage is minimal since the axle isn’t turning the motor. You’ll pay for the sprag quickly with the parts you don’t tear up, and you’ll like how it frees up the kart in the corners. One of the best innovations ever for gearbox karts.