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JohnF2015, Small Engine Technician
Category: Small Engine
Satisfied Customers: 1140
Experience:  Owner/Service Technician at S & J Small Engines
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I am building a electric bike. The total power of the motors

Customer Question

I am building a electric bike. The total power of the motors is less then 1000 watts. I would like to power the electric motors with a gas motor over 49cc. My current understanding is this would still be an electric bike. Is this true? Also I believe the law says it can't power a 170lb rider faster then 20mph when on flat ground and not pedaling. I would like to install a governor that limits speed when not pedaling but no governor if pedaling. I would aproch 40-45mph. Is this OK?
Submitted: 1 year ago.
Category: Small Engine
Expert:  JohnF2015 replied 1 year ago.

Hi, my name is***** will be assisting you.

While this sounds like a good idea it will be difficult to do. What you are going to be required to do is have a generator that will generate the electricity that you need to power the electric motor. The generators are designed so that they run one constant steady speed in order to create the hertz or voltage that you need to operate the electric motor. If you start playing with the engine speed of the generator then you are not going to get the hertz or voltage in order to operate the electric motor. If the hertz or voltage drop too low you will end up damaging the electric motor. The weight of the generator will be another thing that you have to take into consideration since this is on a bike. In order to get the speed control of the electric motor you will have to have an electric poteniometer to regulate the speed of the electric motor, you can't change the engine speed of the generator without causing damage to the electric motor, over time it will burn the electric motor out and you will have to be constantly repairing or replacing the electric motor. Regardless of the electric motor being used, you are still using a gasoline powered engine on the bike and it would fall under regulations from the BMV and law enforcement. If it has a 49cc engine or above it will have to be properly licensed and it requires that you have a drivers license or motorcycle license in order to ride it on the streets or highway otherwise you can be arrested and the bike impounded. I suggest that you check deeper into this by checking your local, state and federal requirements. I know that in my area the law enforcement is really cracking down on these type of bikes and scooters being on the streets.

Thank you it has been a pleasure to assist you.

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