By Richard Westcott
BBC Breakfast correspondent
Riding the world's first purpose-built hydrogen-powered motorbike may be environmentally friendly - and fun - but where does it leave its more traditional petrol-driven cousin?
Weird. Weird and fun. That's what it's like to ride the world's first purpose-built hydrogen fuel cell motorbike.
The only noise is from the tyres and the wind whistling through your crash helmet. People don't look around as you approach - they just stare after you've gone past.
The ENV (Emissions Neutral Vehicle, envy for short) accelerates like a 125cc scooter. It's smooth and easy to control, will do 50mph and has a range of 100 miles.
All that, and the only garbage you're belching into the atmosphere is water vapour.
There are three great big catches though.
Firstly, the bike itself may be completely green, but producing hydrogen isn't.
At present, the bulk of it comes from using up fossil fuels. The whole process isn't as polluting as producing oil but it still has an impact.
Secondly, where do you fill up? Hydrogen is easy to buy, costs about the same as petrol, but virtually no petrol stations sell it.
So unless you're prepared to carry a spare canister around with you, you'd better be careful where you ride.
Thirdly, the first bikes could cost you upwards of £6,000. That's a lot for a small bike.
The makers at Intelligent-Energy in Leicestershire insist all these problems will be ironed out in a few years.
They believe all the big car makers will soon be mass producing hydrogen vehicles by then, forcing the automotive industry to dream up solutions.
Now, the science bit. Hydrogen cells for vehicles have been around since the 1960s.
They work by feeding hydrogen into a chamber, where it reacts with oxygen to create electricity and the only by-product - water.
By the way, if you are worried about riding around sitting on a canister full of explosive hydrogen, the makers say it is no more dangerous than petrol - and you never worry about that do you?
The ENV's been around for a couple of years as a prototype but the designers hope to develop a full-blown production model by the end of the year.
By the way, I realise hardcore bikers will never give up their throbbing combustion engine, but hundreds of thousands of people also commute on their bikes and this will be targeted primarily at people in cities.
I like throbbing combustion engines too, but the ENV was a lot of fun. Weird fun.