My son's friends are starting to smoke him on their mx650s. I'm looking to make his mx500 faster without converting to 48v (for now). I'm thinking about upgrading to the blue 750W motor, but don't know if it makes more RPMs then the stock 500W motor and if it will actually make the bike any faster. If it makes the same RPM, any advice on which sprocket / chain to get for the rear wheel? Also unsure if I would need a new controller to take advantage of the 750W motor.
Looking for a nice little father/son project where we will see some results without getting in over our heads.
The Razor MX500 dirt bike has a 2500 RPM motor and the MX650 has a 2800 RPM motor. This makes the MX650 go around 17 MPH compared to 15 MPH with the MX500.
The MOT-36750 36 Volt 750 Watt motor is 2800 RPM so if it was installed on an MX500 then it should go as fast as an MX650.
The MX500 and MX650 both use the same controllers so I would expect that if used with the original controller the MOT-36750 would provide the same speed as the MX650 has. A 36 Volt 800 or 1000 Watt controller could be installed along with the 750 Watt motor to maximize the amount of power that it produces.
The following sprockets could be installed on the MX500 or MX650 to increase the gear ratio for a faster top speed:
A 500 Watt motor can power a bike up to 20 MPH so the top speed of the bike could be increased by changing to a different size sprocket. This will increase the top speed however it will lower the rate of acceleration. Increasing the gear ratio will also lower the amount of torque that bike has so its uphill climbing power will be lowered unless the motor is upgraded to a higher power one at the same time as the sprocket change.
Please let us know if you have any questions.