Motor Shaft problem

[J Lewis]

Myself and a friend are building each a car to run I have a Nue Motor and he has a Tekno square can motor, I run 5s buggy and his is a 6s truggy, I ran mine 3 races and love it, he just got his and I watched it run one lap just getting the brakes set, when he went to pull wide open the thing just stopped going, when we looked, the shaft was broken off inside the front bearing, are the long pinions to much weight for these motors.---Jerry