Just over three weeks after he broke both the tibia and fibula in his right leg, Valentino Rossi (Movistar Yamaha MotoGP) secured a front row start at the Aragon GP and came in fifth in the race – having also held second for 11 laps.
Such a finish was unimaginable only a few days before the race, and was made possible through Rossi’s incredible talent – and through a specific braking solution Brembo made available to remedy the problem of having a right leg working at less than 100%: the special thumb brake master cylinder. This enables the rider to control the rear brake without using his right leg to operate a pedal.Instead, he simply relies on a small lever mounted under the left handlebar that is controlled by his thumb.
The Italian had already tested the system after the Brno race. The configuration he tested was the “standard” version with a thumb master cylinder and a pedal connected to the same rear master cylinder. With this version it isn’t possible to operate the rear brake with the thumb master cylinder and the pedal simultaneously, only one of the two can be used. But after the injury, Valentino wanted a solution with two separate circuits in order to operate the thumb master cylinder and the pedal at the same time.
Technicians made this change in record time with a new rear caliper.
Practically speaking, the thumb brake works like a kind of traction control: It is activated mid-corner in order to stay close to the tyre traction point, straightening out the bike as quickly as possible. And on right-hand turns, riders with big feet find it easier to use in the peak lean angle because there is no risk of the right boot making contact with the asphalt.