Sheene’s horrific Daytona fling

Forty years ago this spring, Barry Sheene was in Florida preparing for the Daytona 200, the biggest date on the motorcycle racing calendar. A film crew was there, making a documentary about the fast, brash youngster for ITV.

Ten days before the race Sheene is taking part in a private test session, circulating the banking to get a feel for his brand new XR11. Suzuki’s 750cc two-stroke has already been nicknamed the ‘flexi-flier’ for its habit of throwing itself into violent, high-speed wobbles.

It also has a reputation for breaking engines and shredding rear tyres.

Sheene likes the bike, despite the facts. After a few exploratory laps he feels comfortable enough to see what the latest XR11 can do. He’s shifting into sixth gear at more than 170mph when the unthinkable happens. The bike slews sideways, then snaps the other way and hurls its rider onto the Tarmac.

Sheene ends up crumpled at the bottom of the banking, an ambulance skidding to a halt to lend aid to the apparently lifeless body. A motley assortment of medics, mechanics and bystanders manhandle the groaning rider onto a stretcher – no neck braces or body boards in those days – and off to hospital, sirens wailing. Meanwhile Suzuki team manager Mitsuo Itoh, the only Japanese rider to have won an Isle of Man TT, examines the wrecked bike.

Sheene is in a bad way: broken femur, collarbone and arm, several fractured vertebrae and a horribly skinned back, but his recovery was Lazarus-like and, with a little help from ITV, transformed him into a national hero. He raced again just seven weeks later, won his first premier-class GP a further nine weeks later and, of course, took the 500cc world championship the following year.

People still argue over the causes of bike racing’s most famous accident. Who was to blame? TV footage of the aftermath clearly shows the bike with its delaminated rear tyre, rubber strewn all over the track. But the following day the tyre showed 30psi, so it hadn’t blown. Sheene recalled the rear wheel locking, suggesting an engine seizure, so he had whipped in the clutch, but the bike kept skidding, which might indicate a broken gearbox. No, said Suzuki, its post-mortem uncovered no gearbox fault.

In fact the tyre was the most likely culprit, though it can’t take all the blame. Dunlop and its rivals were struggling to keep up with increasing engine performance. One day engineers were making tyres for 75bhp BSAs and Triumphs, the next they were trying to get their heads around the new wave of 100bhp two-strokes from Japan.

The huge speeds and g-forces created by the Daytona banking stirred up a perfect storm of temperature, compression and tyre fling – the tyres crushed into the Tarmac and growing by almost two inches on each and every revolution. Thus Sheene’s swollen, disintegrating rear tyre most likely jammed against the XR11’s swinging arm, throwing the bike into its wobble.

Dunlop was aghast. It’s not like it had been idle; rear tyre design had changed dramatically in three years. Tyres had become slicks and were much wider and flatter. Dunlop had also started working with new technology, using a Kevlar belt around the tyre to reduce fling. Perhaps a faulty batch of Kevlar was to blame. Or maybe Suzuki hadn’t designed enough clearance between tyre and swinging arm. Or perhaps it was a combination of many circumstances.

Sheene’s crash forced Dunlop to withdraw from the Daytona 200, just as it had a few years earlier when it had similar problems with the first XR11, though with less dramatic consequences.

The most shocking aspect of the accident was that it was nothing unusual. There were several similar crashes in 1975, at Daytona and at the Ontario Motor Speedway in California. These were dangerous times to be a bike racer – riding a high-powered motorcycle around speedbowls was like playing Russian roulette.

Tyre worries still haunt the Daytona 200. Since 1985 the event has run under Superbike regulations for race-prepared street machines, initially 750s and then 1000s. However, by 2009 the fastest bikes had 200bhp, creating enough of a headache for tyre companies that the race was limited to much less powerful 600cc racers.

This year the 1000s were set to return to a race managed by MotoAmerica, a new outfit fronted by former 500 world champion Wayne Rainey. It hoped to rescue US racing from several years of disastrous management by the Daytona Motor Group. Perhaps unsurprisingly, MotoAmerica and DMG were unable to agree terms for running the 200, so the race has been taken over by another party. Sadly, the historic event, which started out as a beach race in the 1930s, has very little of the prestige it once enjoyed, to the extent that last year’s 200 wasn’t even televised.