Why do MotoGP riders dangle a leg?
Watching a MotoGP race for even a few minutes will have you wondering why riders dangle their legs when braking. Is it a technical, balancing or distracting manoeuvre? These are questions that crop up in the mind of an observer. As of now, there is no satisfactory explanation to satisfy all pundits of MotoGP. There is plenty of speculation on why riders do it, but no explanation came from the first performer of the antic in a MotoGP, Valentino Rossi.
This article will seek the all-important answer to the question: Do riders benefit from dangling their legs when braking and cornering? A keen observer will note that the leg stuck out is always toward the side that the bike is leaning.
Who first dangled a leg in MotoGP?
It happened in the inaugural Grand Prix of the 2005 MotoGP championship. Valentino Rossi and Sete Gibernau were contesting for the race win in the 2005 Spanish Grand Prix at Jerez. Bot riders were heading into Curve Lorenzo, the last curve in the last lap before the finish line. Rossi was attempting to pass Gibernau on the inside in a bid for the win.
Rossi pulled off the pass by sticking his inside leg out and somehow coming out of the curve ahead. Gibernau rode off into the dirt even as Rossi won the Grand Prix with ease. The move looked funny at first, even comical. But Rossi was a living legend and he had won the race, hadn’t he?
The move soon caught up both in MotoGP and in lesser races. Every rider worth his salt tried to hang his leg out when cornering. Most could not understand the reason they did it. Many could not explain the advantage they gained by hanging out a leg. Today, in any race one watches for any length of time, at least one rider will dangle a leg when braking.
Many theories are banded on how dangling a leg helps the rider. The opinions differ from one to the other. Some feel that dangling a leg offers more resistance to the air flowing around the bike. This helps the bike slow down further. Others simply think it is a distracting technique. Many also think that it helps hinder a rider trying to pass on the inside of the curve.
Many are of the school of thought that dangling a leg helps the rider balance the bike better. Still, others offer that the sticking out of the leg lowers the centre of gravity of the bike and transfers weight to make the bike stable. There are many riders themselves who claim that they do it but do not know why! They say that they just dangle their leg when they feel it is the right thing to do!
What are the benefits of dangling a leg while cornering?
Whenever a rider is braking a bike he has to brace his body against the retardation. If he can increase the surface area resisting the air, that would help brace his body as well as slow down the bike. Sticking a leg out of the aerodynamic line of the bike might just serve the purpose. The stuck out leg will be braced against the retardation by the air resistance.
If a rider is braking and leaning a bike into a corner, It doesn’t make sense to brace his weight on the inside. Bracing inside would only serve to tilt the bike further. Hanging a leg out for greater resistance seems to solve this problem. This could be one of the advantages of sticking out a leg when cornering.
Letting a leg hang means the weight is transferred from the footpeg toward the rear. The weight of a foot is s sizeable proportion of body weight. This will shift the centre of gravity of the bike backwards and lower. The lower the CG, the less the bike has to lean. This allows the bike to grip the track surface with a slightly broader part of the tyre. A better grip increases the speed of cornering.
Stocking out and lowering a leg will distribute the rider’s weight better. A bike with more weight transferred backwards will be more stable when cornering. The extended leg may also thwart a rider trying to pass on the inside. There could be many more explanations for how dangling a leg helps a MotoGP rider.
Sylvian Guintolli is an ex FIM World Superbike Champion and the current test rider for Suzuki MotoGP. He tried to explain the benefits of dangling a leg while racing. Here are some of the reasons riders dangle a leg…
- If a rider brakes hard enough his legs will lose their grip on the pegs because of their inertia.
- Dangling a leg lowers the centre of gravity of the bike which increases braking stability and decreases the lean angle required to negotiate the curve.
- A part of the bodyweight is transferred backwards increasing bike stability even more.
- Lowering the inside leg gives the rider more strength to balance the bike with his arms and outside leg.
- The dangled leg increases resistance to the air ever so slightly helping the bike slow down quicker.
The Leg Dangle Explained Video
Why do MotoGP riders dangle a leg? – Conclusion
The advantage gained from dangling a leg in terms of time looks very small. But a position in a Grand Prix may be gained or lost for the want of a millisecond. Riders will want to try every gimmick to gain a few milliseconds and a position in a race. If Rossi won a Grand Prix by dangling a leg, why not give it a go? Dangling a leg when braking, has come to stay in MotoGP.