His latest innovation, the Zeta, is a shoebox-sized device that turns an ordinary bicycle into an electric one. A quick road test at the London launch yesterday revealed either a design problem or a cunning safety feature.
The lid of the box, apparently held on by just a strip of Velcro, clattered to the ground as I rode slowly down a shallow kerb. Could this be intended to deter cyclists who enjoy bumping up and down kerbs?
The Zeta (Zero-Emission Transport Accessory) is available by mail order only from this weekend. Sir Clive hopes to eventually sell it through bicycle shops.
It is aimed at people who might enjoy the freedom of cycling, but are wary of hills or do not want to get too sweaty. The electric motor, similar to those used in electric wheelchairs, is kicked into action by pulling a small red lever on the handlebars. This has to be held on all the time (a legal safety requirement so the unit cuts out after a fall), making braking with the left hand tricky.
Two years ago, Sir Clive launched the pounds 500 Zike - a wobbly electric bicycle with small wheels. He claims to have sold 'over 2,000' but admitted his original target was substantially higher. The Midlands-based company that was to manufacture the Zike had an initial production target of 10,000 bikes per month. When asked what happened, Sir Clive said yesterday: 'We guessed wrong.'
Other designs for electric bicycles have usually included small rollers that sit on the side of the tyre. Sir Clive's new unit sits on top of the back wheel, where a luggage rack would normally go, and uses a smooth, rotating rubber belt to transfer power to and from the wheel.
Downhill, the Zeta limits the bike's speed to 15 miles per hour - the legal limit for electric bicycles - with excess power fed back to the battery. If the rider lets the Zeta do all the work its sealed lead-acid rechargeable battery will last for 10 miles. If the rider pedals as well, the range can increase to 30 miles. The Zeta is recharged overnight, at a cost of about 1p, Sir Clive said.
Riders need no tax or licence, but must be over 14 to use the Zeta on public roads. The unit costs pounds 144.95 and weighs 10lb.