[Al Skierkiewicz]

Benson,
The wheels can cause some excessive vibration in the motor and that puts some intermittent loads on the motor. The output bearing is not meant for a lot of side loading so depending on how often you run this motor up to speed, it may produce some early wear in the bearings eventually leading to failure. As you prototype check the temperature of the motor every once in a while. If it doesn't pass the 5 second touch test, you are over stressing the motor. If it is warm to the touch but you can hold your hand on it for five seconds, it is likely running normal.