Electric Bike project description

This project came about through a number of events. Firstly, in October 2000, we had the petrol crisis plus the following floods that made matters worse. Then I went to the NEC Bike show and saw an electric powered bike by “Zappy”. Then the Ural became increasingly difficult to start, probably requiring a rebore.

With all this I thought about the Zappy bike and reckoned I could do something like that. With the engine out of the Ural I had a strong frame that could take the weight of batteries.
I checked with my work place and they will allow me to use one of the mains outlets, in the car park, for the use of charging an electric vehicle. This means that I will be able to extend the life of the batteries with the extra charge during the day.

I found E2V on the Internet, they are a good source of components and knowledge on all things concerned with electric powered transport. After some talks with them a decision was made to use 6 x 12volt batteries to give a 72volt supply. The motor was to be a LYNCH permanent magnet type and this will be controlled by a CURTIS PWM unit.
The batteries will be held in an aluminium frame, 4 in the engine area and the other two will be behind the riders feet, doubling as the pillion foot rests.

I made a dummy fuel tank from bits of MDF, these were varnished and painted black to keep it weather proof. It will be used to hold the volt and current meters and to protect the pot-box and other electrical bits.

The pot-box was connected to the ends of the throttle cables, using a suitable hole in the actuating arm to give full movement with the twist-grip. I tried to get away with using one of the throttle cables but this caused the twist-grip mechanism to jam.

While the twist-grip was in pieces I added the one thing that Urals have lacked (until recently), an electric start. This a push button that will engage the main contact breaker. I connected this with the kill switch so that the operation of starting and stopping the bike will be identical to a petrol one. The exception is the addition of a circuit breaker in the middle of the battery pack to render the lot safe when parked in public, just in case someone pokes their finger where it shouldn’t be.

Using a tried and tested figure for calculating the expected range, I am hoping for about 25 miles. This will be enough for commuting, shopping and visiting local biker haunts.



I get the batteries >>>>>>

I Thank the following for their services and advice:-
E2V : For supplying components and offering advice.
Camberley Engineering Farnborough : For machining work.
Maplin : For numerous components; ordered online and delivered within 24 hours !