Electric Bikes
Why bother to have an electrically powered bike? The answer will depend on your personal circumstances. Some will find electrical assistance necessary due to a disability or poor health. Others will be returning to a bike after many years and need some encouragement! But whatever the reason electrically assisted bikes are an eco friendly form of transport and great FUN!
I get a lot of email about the 'Heinzmann' - particularly asking if it will work in the wet. I have been very wet and the motor still works!!
E-bikes in the UK
There are several ways to apply drive to a bike:
1. Friction - the motor has
a small wheel which runs very fast and drives directly onto the tyre.
2. A hub motor - the motor in enclosed in the wheel hub.
3. Chain drive to the rear wheel - not very common.
4. Drive to the bottom bracket - factory built electric bikes.
Friction drives do work but can suffer from poor drive due to mud and water. The best on the market is the Zap.
Hub motors are best, they are neat and work equally well in the wet or dry. They are heavier as they need an internal gearbox to match the wheel speed to the speed of the electric motor. Look out for a new, smaller, lighter (2.5Kg) motor from the US due to go into production in April 2000. (See the Ex-Bike below)
I have only ever seen one chain drive, it connected to an extra sprocket on the opposite side of a rear wheel. It worked OK but was a little 'chunky'.
Bottom bracket drives are only found on factory built electric bikes. They can be very sophisticated in that they will match power from the motor to that supplied through the pedals but don't usually offer drive independent of pedaling.
There are not so many motor kits or e-bikes available in the UK. The famous Sinclair Zeta is perhaps the most well known (pity!) It has received very bad reviews but has brought the subject to the attention of a wider public.
Choices
The best retrofit kit is the Heinzmann hub motor. It is a very neat and
sophisticated unit which is fitted into the front wheel (there is a also
rear wheel option) with the battery and control gear located in a box
fitted to a special rear carrier. There is a new design now available,
the old black box is being phased out - see http://www.kinetics.org.uk/html/about_heinzmann.shtml
June 08 update
A relative newcomer in the UK is the Nano. It is a small hub motor supplied
fitted in a wheel of your choice. Price looks similar to the Heinzman.
There are a couple of battery options. From their site it looks as if
it is aimed very much at the folding bike market.
http://nano-motor.co.uk/index.php
A good idea
A folding electric bike
was developed by Rabbittool in the US. The "Ex-bike" was based
on a Dahon Helios using a revolutionary 24V AC motor. The motor had a
regenerative braking facility which means it recharged the battery when
breaking.
After several years the Ex-bike is still not on the market. I recently contacted the company (Nov 2005) but got no response. Another good idea that died?
The best overall site for information about electric bikes is: www.electric-bikes.com (US)
The Heinzmann hub motor
The Heinzmann battery box and control gear.