Why MotoGP riders dangle a leg when braking

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Words: NZ Autocar
7 Apr 2020

It has become natural for MotoGP and Superbike riders to dangle a leg during heavy braking into tight corners but have you ever wondered why they do it?

Valentino Rossi was the first to drop an inside leg, around 2005, and others simply followed because at the time he started the “Doctor’s dangle” he was pretty much unbeatable. When asked why he did it, he merely stated it “felt natural”.

But there’s a bit more to it than that, as Frenchman and ex WSBK champion, Sylvain Guintoli, has described in a recent YouTube video. The ex-racer is also a MotoGP test rider for the factory Suzuki team.

There are a few reasons he posits that you’d probably guess from first principles. For example, the leg dangle lowers the centre of gravity while braking, moves weight more towards the rear of the bike, improves the body position so the rider feels more planted, and increases drag so the leg acts like an airbrake. He adds that each of these effects is minor but they all add up to a small advantage and in MotoGP it’s the bits of tenths per lap that count.

Guintoli said that for the vast majority of track day riders there is no advantage whatsoever, unless you’re going for a lap record and then it might be worth a shot.

Not everyone was convinced of the leg dangle. Rossi’s great rival, Spaniard Jorge Lorenzo, steadfastly refused to adopt the manoeuvre, at least initially, and went on to become world champion regardless. However, Marquez is a big fan, and reckons it simply helps to get the bike turned better.

Royal Enfield May 2020
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