Guest Blog: Mat Oxley - How MotoGP anti-jerk works

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.


How MotoGP anti-jerk works

The last in our series of blogs explaining the mysteries of MotoGP electronic rider aids

OK, enough with the sniggers. This isn’t a clever computer program that helps exasperated MotoGP engineers deal with petulant, prima-donna riders, it’s an important rider aid that’s become even more so since the advent of unified software.

Anti-jerk helps riders get through the transition from off-throttle to on-throttle in the middle of a corner. As they enter the corner they have the throttle fully closed, then when the right moment comes they start to ease the throttle open. At this point the engine goes through a transition from negative torque to positive torque, which causes tolerances in the transmission to deliver a jerk (or hit) in the engine. With so much lean angle and so much torque available, this can disastrous, either ruining the rider’s drive off the turn or triggering a slide from which he or she won’t recover.

Anti-jerk fixes these problems by reducing torque by up to 100 per cent for a few milliseconds.

Our graph shows a rider (we don’t know who because Magneti Marelli keep that information secret) riding through turn eight at Jerez, the 80mph left-hander that takes riders into the circuit’s famous stadium area.

As always with these data analysis graphs, don’t be put off by the apparently confusing mass of squiggly lines; just focus on the numbers and associated captions. 

Read the rest of Mat Oxley's blog on the Motor Sport Magazine website.

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Comments

After these series I wonder if electronics ares used in steering damping. Some years ago, besides highsides. a speedwobble was one the most fearsome events onboard. With the result of massive steering damping devices hanging quite out of place on the bike. Nowadays you dont see that much speedwobbles anymore (maybe also due to electronics in powerdelivery and wheelymanagement), but I cannot spot the steering damping devices anymore.... Any thoughts on that?