# Motors & Torque Converters



## Anaerin (Feb 4, 2009)

I think this has been looked at before. The main reason it probably isn't considered that much is that a spinning motor takes power, and to get the motor up to speed and back down again would burn more energy than the little "wasted" energy used in starting an electric motor from 0rpm.


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## SimonRafferty (Apr 13, 2009)

In addition to what Anaerin has said, CVT's, at least the belt drive ones used in motorbikes, quads etc are not in themselves as efficient as a gearbox made with spur gears or chain.

Some types of motor (AC Induction and Brushless DC) are actually most efficient at low RPM as the frictional losses are lowest. Series wound can generate very large torque at low RPM, at the expense of being inefficient there.

However, there might be some mileage in using a motor to spin up a flywheel which in turn is connected to the wheels through a CVT. The regenerative efficiency of the flywheel compared to an electric motor / batteries may overide the inefficiency of the CVT. The motor can drive the flywheel through a clutch so it is not running all the time and is just used to top up the flywheel. The accelerator then just changes the CVT ratio.

I think, having thought about it, that the added complexity would put most people off! 

Si


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