Race Deflations Lead to Australian Tyre Controversy

In Australia the motorsport highlight of the year is arguably the Bathurst 1000 (the Supercheap Auto Bathurst 1000, to give its full, sponsored title) race. This event is a celebration of the V8 saloon so popular down under and enjoys a large and dedicated following from petrolheads and race fans alike. However, following the latest Bathurst race, round ten of the V8 Supercar Series held on October 12, all is not well – controversy hangs in the air, and luckily for us it is tyre related.

Race runner-up Greg Murphy has demanded a new control tyre for the series to replace the current Dunlop tyre, reports v8supercars.com.au, official website for the race series. These comments were made after the race event, during which many teams suffered problems with their left-rear tyres.

“Fix it,” was the curt message Murphy had for V8 officials and Dunlop. “I’ll tell you what, I’m getting sick of coming here and having tyre problems. It’s beyond a joke; why can’t it be fixed?” Murphy suggested that a rim size larger than 17-inch could provide a solution.

“We’re well overdue for it (a larger rim),” he stated. “I’m sure there’s a solution; I have no doubt about it. I’m not a tyre guru, but I’m just saying how long do we have to put up with it? I’ve been going on about this bloody tyre for yonks, for years going on about it.”

Unsurprisingly, Dunlop’s Kevin Fitzsimmons does not agree with Murphy’s diagnosis, stating instead that the race circuit was the cause of all tyre issues during the October 12 race. Fitzsimmons inspected portions of the circuit post-race to get to the bottom of the tyre problems. “It’s just one of those things, but it’s circuit specific to Bathurst,” he mused. “Phillip Island’s the highest loading of any track we go to by a mile, but it’s a different type of loading. There is a lateral loading at that circuit whereas at Bathurst it’s a vertical load with the pounding the car gets up and down the Mountain from the actual bounce of the car.

“Whether it’s an impact or rocks are going through and cutting it, we don’t know but it’s significant they are all left-rear tyres, which are not traditionally what you would call the loaded tyre of the circuit,” he added. “We’ve got a bit of homework to do over the next few weeks.”

Ford Performance Racing’s Mark Winterbottom has lent his support to Fitzsimmon’s evaluation of the problem. “It’s not the tyres that go, it’s the track that is causing the tyre to go,” he said. “There are some spots on this track that the kerbs need to be repaired and done properly and that’s what keeps cutting the tyres.”

Fitzsimmons said the track did not delaminate the tyre, as many people along pit lane claimed, but damaged the cap ply which is a rubber-impregnated Kevlar cord bonding the tread to the tyre carcass for strength. “It’s breaking the cap ply on the tyre so it loses its strength,” he explained. “It’s like a ligament in your knee; everything’s still there, but you’ve got no strength in it. Once that goes the tyre has a soft spot in it; it works very hard on that soft spot and there’s no strength there and it blisters.”

Fitzsimmons said when the blister tore open, the cap ply poked through. “And you load the tyre up, whether it be at the Chase or turn two… it grabs hold of the piece of cap ply and tears the tread of the tyre. So it’s not a delamination of the tyre at all.”