“Why do I do it? For the thrills… the adrenaline… to prove a point – that as a wheelchair user I am still capable of doing scary things – and I love doing scary things.”

“Downhill” Phil Hall is a bit of a nutjob. Has always been a thrill seeker, but a decade ago, like increasing numbers of paraplegics, he snapped his back in a motorbike accident. He could no longer walk; had to use a wheelchair. He had no idea where he’d find a sport that would get his pulse racing again.

Then he discovered gravity biking while on holiday in Colorado.

It’s a kind of cross between mountain biking and go-karting. No engine. No pedals. One objective – just get to the bottom of the hill as fast as you can. And it’s getting adrenaline junkies like Phil back outdoors.

He imported his own bike as soon as he could – and was introduced to Dave Bower by the manufacturer. Dave is a pilot. He used to fly stunt planes in his spare time. But a trick went wrong. He snapped his spine. And he lost so much more than his mobility.

“My friends were all into extreme sports,” he explained to me, perched in his gravity bike on a rather windy hillside in Snowdonia.

“But all of a sudden I couldn’t participate.”

Mates being mates, they’d invite him along anyway – but he’d find himself sitting in the car park, kind of wishing he wasn’t there at all.

Then he too heard about gravity biking.

“Mountain biking was a massive part of my life. This replaced it. It’s made a hell of a difference”.

Phil and Dave are trying to spread the word. They got hold of another gravity bike and started holding taster sessions for other paraplegics at mountain bike centres in the Highlands and Wales. And they have a big vision.

Their existing bikes are obsolete – the Canadian company who used to make them has disappeared. So they are designing their own. Lighter. Cheaper. And they want to take it global.

The Welsh government recently got wind of the project, and invited Phil’s team to apply for hundreds of thousands of pounds in seed funding.

Their chief designer is an engineer at Gower University. A keen mountain biker himself. Former podium racer indeed. Who knows just what’s it’s like to be deprived of an adrenaline fix.

Calvin Williams spent a year in a wheelchair after he slipped 100ft down a hiking trail. He’s now registered disabled, and can’t walk far before the pain gets too much. He was developing his own ideas for a sports wheelchair when he heard about Phil’s plan , realised how advanced it was, and offered them his services. He’s astounded at how much attention the gravity bikes attract when they turn up at a trail.

They already have support from several hi-tech local companies – including an aerospace firm, and a piston manufacturer – and they’re refining plans for new tubing, chassis, and suspension. As well as a new type of carbon fibre seat.

“We’re trying to tie up our intellectual property rights,” he explained. “And if we do – if it does go global – potentially we could do very well.”

And it doesn’t end there. Which is where the engineering stops and the adrenaline kicks in. Because once they’ve got the bike right, they want to create a vibe – a “scene” – and a brand new competitive race series.

From local, through national, to possibly Paralympic level. Something those in disability sport agree is aiming rather high, but certainly not unthinkable.

And the vision has already got people’s ears twitching. Both disabled and non-disabled riders. Indeed, they’ve captured the imagination of some in the (two-wheeled) mountain biking elite – who want to try it too.

On the way down any given hill, every now and then, gravity bikes of course will come to a halt. They tend to ride in a group alongside traditional mountain bikers, who can lend the odd bit of horsepower to help get them over obstacles, or the odd incline. In Phil’s posse this blustery autumn day was Dave Buchanan, world record holder for endurance mountain biking.

“Anyone who wants a challenge”, he says, “will want to give this a go. Not just disabled athletes but able bodied too.”

“Any mountain biker you see, wants to sit in it,” attests Calvin Williams. “And wouldn’t it be nice to have disabled and able-bodied bikers racing on a level playing field?”

Ambitious? Certainly. Realistic? Maybe. Fun? Oh yes.

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