MotoMatters.com is delighted to feature the work of iconic MotoGP writer Mat Oxley. Oxley is a former racer, TT winner and highly respected author of biographies of world champions Mick Doohan and Valentino Rossi, and currently writes for Motor Sport Magazine, where he is MotoGP correspondent. We are featuring sections from Oxley's blogs, which are posted in full on the Motor Sport Magazine website.
Can Rossi find a way out of his nightmare?
MotoGP’s old warhorse had a dismal start to his 25th season of world championship racing, complaining of the same old rear-grip issues
Poor old Valentino Rossi. Another year and he still sounds like a broken record. At Jerez his problem was the same as it’s been for the last few seasons: too much rear-tyre temperature and therefore not enough grip or tyre life.
Michelin has heard the story so often that its MotoGP chief Piero Taramasso was moved to suggest that the problem was Rossi’s own. “Rossi has a particular style – he leans off the bike less than the others, which stresses the edge of the tyre more, so the temperature rises,” said Taramasso on Friday.
The seven-times premier-class champion didn’t appreciate the lesson in riding technique and responded robustly on Saturday.
“I don’t agree with Taramasso,” he said. “If you look at photos it’s clear I’m a long way out of the bike, because we work a lot on this. With the Bridgestones I was more out of the bike than I am now. With the Michelins you can be too far out.
“My position on the bike isn’t the problem. For example, [Andrea] Dovizioso is another rider whose style isn’t so far out of the bike. So for me this isn’t the problem. Usually in my career I always prefer hard tyres, both front and rear. In the past I’ve ridden the best races of my careers with hard tyres. Now the Michelins are very soft – very soft casing and very soft rubber – so for me it’s not easy.
“Also, I’m taller than average and although I’m very skinny my weight is quite high, because I’m quite tall. But on the other hand I agree with Taramasso that the problem is mine, not Michelin’s, because the other guys are fast, so I agree with him that we need to find a way, but I don’t agree that I’m not far enough out of the bike.”
Motorcycle racers have been hanging off their motorcycles to go fast since the early 1960s. Australian Tom Phillis was probably the first to use the technique successfully when he won the 1961 125cc world championship. Phillis began shifting his weight to the inside of the bike to improve handling. Leaning off achieves this by reducing lean angle and reducing the forces on the tyres.
Anyone who leans off their motorcycle does so for these reasons and to reduce centrifugal force while cornering, which helps the bike turn. During the last ten years, MotoGP riders have leaned even further off their bikes in search of faster lap times.
When Rossi arrived in 500s his upper body stayed pretty much in line with the rear tyre. More recently the rear tyre and upper body make a V shape, with the upper body at an even more extreme angle. Comparing photos of Rossi and Yamaha team-mate Maverick Viñales suggest that the Spaniard does hang off slightly more, but he’s lighter, so the physics are different.
Rossi is certainly correct when he says has always preferred harder tyres, both in construction and compound.
Read the rest of Mat Oxley's blog on the Motor Sport Magazine website.