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******About spur size****
A bigger spur= more acceleration/ less top speed.*
A smaller spur= more top speed less acceleration
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*** big .v.s. Small pinions***
*Larger pinion = Less torque at the wheels, more top speed (up to a point before it's too large), less acceleration, more stress on motor and heat.
*Smaller pinion = More torque, slower top speed, better acceleration, consequently better runtime, less heat and stress on motor.*