Guy Martin on attempting the wall of death at 100mph — and why he might black out...

I meet him on the specially constructed wall. It’s colossal. So big, it’s housed in an aircraft hangar somewhere in mid-Lincolnshire. I hear it before I see it. I smell it before I see it. The smell is of petrol. The sound is a booming motorbike roar. I climb up to a platform and there, at the base of the wall, is Martin, speeding round and round like a bee at the bottom of a glass.

He’s not going fast enough to get on the wall. He’s on the “banking track”, at a tilt of 40 degrees. To get vertical on this huge wall, he needs to be going at 57mph. That’s what you need to achieve the 2.5 G-force to “stick” to the wall. Martin hops off his bike and comes over, grinning. “It’s harder than it looks,” he says, with a fair degree of understatement. “You have to get your brain to calculate what’s happening. You have to recalibrate your senses.”

For anyone who’s interested in taking on wall-of-death riding, here goes. Ignore the front wheel of the bike. Don’t look forward. Tilt your head back, and look at the top of the drum. Don’t worry about where you are, because you won’t know where you are. Just keep moving, fast. And keep the red line at the top of the drum in the corner of your eye line. And don’t worry when your vision goes. Whaat?

It’s all about the dreaded G-force. The faster you go, the more Gs you create. Going at 57mph on the big wall will keep you stuck on. But Martin doesn’t want 57mph. He wants 100mph. How much G is that? “Just short of 10G.” And? “Well, I’ve been put under 8.5G in a stunt aeroplane. I felt all right. Well, I lost my vision, but I was still conscious. I know I'm going to black out, but it's good. I will get a warning before I black out. Maybe I'll black out before I pass out. That's called GLOC, which stands for G-induced loss of consciousness."

Oh, great.

Imagine the scene. The nation sits down to watch TV, opening seasonal confectionary. Martin and his special bike, which he has built himself in his garden shed, is on the wall. He does one lap at 57mph. He gives it some welly. He goes up to 80mph. He loses his vision. He touches 100mph, and blacks out. A nation chokes on its collective stash of Creme Eggs. Martin assures me this is very unlikely. Not Going To Happen. "When I'm under the situation of G and my vision starts going, I will think, 'Ah right, I'm losing my vision, I'm about to black out', so I will know to back off the throttle.

I’m man enough to know when it’s not safe to go under GLOC. I’ll come off the throttle. But if you keep putting a body under that situation it keeps dealing better with it every time, so hopefully I can train my body to cope.” He’s got some special G trousers, which apparently hold the tension in your legs and keep the blood where it should be. “We can blow them up with a pushbike pump, if we need to.”

A bike pump? Oh, Guy. He’s so normal. He’s going to pump up his trousers and, as he puts it, “go as fast as humanly possible”. In a very English way. “As dull as it sounds, I will not be going through any of that haka business before the race.” What, no chanting and hugging? No way. "you can't get all American in there, because that's when it gets messy. All I will be doing is going through the motions. A 30-second set routine. I’ll get the bike started, go onto the Wall, get up to speed, spend one lap at the speed, slow down, get off the Wall and then stop. That’s how you’ve got to deal with it.”

Although even he admits he is a bit nervous. “I am massively outside my comfort zone. Which is great.” Indeed, the old Martin programme such as the TT race on the Isle of Man is old hat. “I’ve been doing the TT for 11 years, and it’s a fantastic event, but for me it’s lost its edge, really.”

Is there going to be a time delay, just in case the unthinkable happens? Indeed, there is. “But I’m not scared of crashing. What am I going to hit? The only time it will get messy is if I hit the bike. The only thing I am going to crash into is the wall. Hopefully the radius of the wall will take the energy out.” I feel nauseous just thinking about it.

After the Wall of Death at 100mph, Martin is taking it easy. Racing through America on a pushbike. Unsupported. Sleeping in bivvy bag by the side of the road. And when I say ‘through America’, we are talking Canada to Mexico. 2745 miles. “I want to try and break myself,” smiles Martin amiably. Any other concerns? “Well, my only worry is that the race starts on June 10, which is when bears are coming out of hibernation.

I’ll have a Bear Whistle but it is a bit tricky because you have to tell the difference between a black bear and a brown bear. You whistle at a brown bear but not a black bear.” What do you do with a black bear, then? “With a black bear you have to pretend to be dead,” says Martin casually. “But a brown bear can look like a black bear when it’s coming out of the water. It can get a bit confusing.” Why don’t you stay in a B&B for that bit of the race, I suggest? “You could do but I am not doing that.” He smiles. “You always have to have goals, don’t you?”

Guy Martin's Wall of Death: Live is on Easter Monday at 7.15pm on Channel 4