Guy Coulon & Wilco Zeelenberg Explain the Leg Wave

12/19/2012 @ 3:29 pm, by David Emmett20 COMMENTS

Guy Coulon & Wilco Zeelenberg Explain the Leg Wave dani pedrosa laguna seca 1270 635x423

Watch a modern MotoGP, Moto2 or World Superbike race with a casual fan and you can be certain there is one question they will ask you: “Why are they waving their legs about like that?” Many theories have been offered, often directly contradicting each other.

For example, several years ago, I suggested that the leg wave is entirely mental. Earlier this year, the Australian motorcycle coaching organization MotoDNA described the possible role which aerodynamics play, the exposed leg helping to create more drag. Much has been said, yet it seems impossible to settle the argument one way or another.

Asking the riders to explain does not help much. It is a question I and other journalists have asked of many different riders, including Valentino Rossi, Casey Stoner, Cal Crutchlow, and Dani Pedrosa. Their answers always boil down to the same thing: “It just feels natural,” they say. An interesting response, perhaps providing an insight into how deeply racers have internalized so much of the physical part of their riding, but not doing much to help explain the phenomenon.

To attempt to get to the bottom of this mystery, I turned to some of the best minds in the MotoGP paddock. For an explanation of the physics behind the leg wave, I asked Monster Tech 3 Yamaha crew chief and technical guru Guy Coulon, while for further insight from the point of view of an observer and ex-rider, I spoke to Wilco Zeelenberg, team manager of Jorge Lorenzo – the one current MotoGP rider who does not dangle his leg while riding.

The answer, said Coulon, was not simple. “This is quite difficult to answer. We can believe that when you put your legs in this position on braking, the center of gravity is more inside and you can keep straighter on braking for a longer time.” So was the point of the leg wave to move the center of gravity of bike and rider? “I think so, because on braking, you have to be quite straight on the bike, so you cannot move your shoulder or anything else,” Coulon replied.

Coulon accepted that the mental aspect could be one reason which riders dangle their legs. Could it be that seeing other riders do it, and believing it conferred an advantage, other riders start to copy the behavior? “Yes, of course,” Coulon agreed, but more physical aspects also played a role. “But maybe also because of bike geometry, and the kind of tire being used, and what they are able to do on corner entry, so step-by-step they can use this sticking the leg outside,” the Frenchman added.

“But for me, it’s really complicated to explain.” He had seen the maneuver become ever more prevalent among riders, Coulon said. “Like everybody else, I can see step-by-step, one rider, two riders, and more and more riders are using this style. But themselves, they don’t know really why, and sometimes they don’t feel they are doing it.”

In a previous article, I argued that Valentino Rossi was one of the first riders to start to use his leg off the pegs on a regular basis, and that the fact that he saw other riders copying him gave him a confidence boost and a mental advantage. Though Coulon emphasized that he believed there were sound physical reasons for the leg wave, he agreed that riders tend to watch each other closely and copy each other.

“I think it is similar to when the first riders started to use sliders on the knees. One guy started to do that because it helped him control the slide, and it was like a sensor to check the lean angle, then after this, everybody started to use this style,” Coulon explained. “But I think [dangling] legs outside can be used for better stability, and to keep the center of gravity center more inside in the corner where the rider is going, to keep the bike straighter for longer, to keep it in the same position.”

Was there any evidence in the masses of data collected after every session which might help to explain exactly what was happening? “I think it’s a bit complicated to see on the data,” Coulon said.

“Maybe if someone was focused on this and tried to find something in the data, they could. We didn’t try. But for sure, using data, it would be possible to test with a test rider, for example, and we could understand with the same speed, the same deceleration, the same line, with the legs [dangling] outside or not, if the angle is same or different. But for sure angle would be different.”

The question is whether a test rider would even be capable of performing the test, as the styles required are so very different. “It’s not so easy to ask one rider to change his style only to compare the data,” Coulon added. “It seems they are doing it without thinking, finally.” Mainly, it was a question of balance, he said, the leg being used “like a tightrope walker uses his pole to keep his balance.”

The one rider who does not use the leg wave is Jorge Lorenzo. “Yes, but Lorenzo is very stable on the brakes, because of his own style,” Coulon explained. “Because he is really really smooth everywhere, so we never see him with real jumping on the brakes, he controls everything very smoothly, he brakes, releases the brakes very gently. and early. He can carry a lot of corner speed, then also opening [the throttle] he is very smooth. It seems he needs to find less extra stability, because he is already stable because of his own personal style. He always looks very clean.”

Wilco Zeelenberg agrees. As Jorge Lorenzo’s team manager, part of his role is as acting as rider coach and helping identify areas where the Spaniard is having problems. As part of this, he spends a lot of time at track side watching Lorenzo, and assessing what is going on. Zeelenberg agrees with Coulon, it is the smoothness of Lorenzo’s style which precludes him taking his feet of the pegs.

“He’s not really an extremely late braker,” Zeelenberg said. “He wants to keep his bike as stable as possible, as soon as you take your leg off the peg the bike begins to wander, and you have to search for stability. It looks to me like they [the riders who dangle their legs] are looking for stability this way, because they have so much pressure on the front wheel. They are trying to gain some control over the bike, to keep it stable, but [Jorge] never lets it get that far.”

So Lorenzo is creating stability in a different way? “He brakes a little earlier, but in a different way, so he never arrives at the corner with the bike on its front wheel, which makes it want to go all over the place, which makes you lose control. Your foot is a good lever to handle this.” Lorenzo arrives at the corner with the bike already under control and at the right speed, Zeelenberg explained.

As a rider, Zeelenberg said, he had never taken his leg off the pegs, so he could not speak from personal experience. But he could see how it seems to work for some riders, from the time he has spent at trackside watching. “It seems to have a limited advantage. So I think for some riders, especially really late brakers, it helps,” Zeelenberg explained. “When you brake really, really late, your heart rate goes up a lot, your pulse starts really racing, and you stiffen and cramp on the bike. That’s no good. By throwing your leg off the bike, you relax again, which makes it possible for you to stick the bike into the corner.”

“The leg helps with this,” Zeelenberg continued, “because you can throw the bike to the left a lot more easily. If you’re braking, and thinking ‘Shit! I’m too late,’ at the moment the riders get that ‘shit!’ feeling, that’s the moment they take their foot off the peg. They realize that at the moment they have that feeling, and stick their leg out, they can still make the corner.”

It is a way of breaking through their own mental fear of braking too late, Zeelenberg explained. “Everyone has a sort of mental barrier at which point you think ‘Shit, I’m not going to make it,” at that point, you cramp up even more, and then you won’t make the corner.” So it is a way in which riders force themselves to loosen up again, to take away the cramped stiffness?

“Yes. But also, it’s left-handed corners. None of them stick their right legs out if there’s a left turn coming. So it definitely has something to do with balance, but also with forcing the bike into the corner at the moment you stick your leg out.”

Photo: © 2012 Daniel Lo / Corner Speed Photo – All Rights Reserved

This article was originally published on MotoMatters, and is republished here on Asphalt & Rubber with permission by the author.

Comment:

  1. I’ve tried sticking my leg out just for fun, at no where near the speeds these guys do or with braking so hard, but i did have flash back to riding on the dirt. On dirt it’s a little more natural to feel the rear of the bike get squirrely and i could see that being a reason of why it “feels natural”.

  2. Good point Cranky. I’ve often wondered about all the off-road cross-training the riders do, and what sort of influence it has on this subject.

  3. John Orchard says:

    I had been doing the leg wave well before we saw Vale doing it, it is a balance thing, just as a tightrope walker uses a pole, the leg has a great deal of weight, with it hanging out away from the bike the rider can manouvre the bike around more plus if the bike is sliding on corner entry (as most world class riders bikes are) having a tightrope walkers pole (your leg) gives much more stability & confidence. Riders such as Jorge who ride with much more confidence are more exacting in their style and don’t require the confidence that the leg wave gives to other riders.

    I could know what I am saying, I’ve finished 9th in the Australian Superbike Championship, 19th in World Superbike races, competed at Isle of Man TT, finished 4th on the banking at Daytona and run Australian roadrace schools since 1994 and mx schools since 1984.

  4. Mitch says:

    “… the leg being used “like a tightrope walker uses his pole to keep his balance.”

    This is what I always thought/felt. By separating the foot from the peg, the leg becomes a move-able counterweight, and also it eliminates the input of that weight against the bike from the leg muscles (since you can no longer brace against the peg). Makes sense that it helps keep the bike straight against the front for very linear, hard late braking. Interesting then, that this also makes dipping into the turn and finishing strong harder, as the bike is less/not yet stable; Lorenzo, already being stable, then probably counts on apexing turns faster and cleaner.

    Which revolves around why I think he does so well in current MotoGP, where the bikes are so powerful that those riders that adhere to what the ECU engineers program in do better than riders that may have more raw skill or take more chances. (explaining how Moto3 and 2 are more exciting to watch than GP… but that’s a talk for another article.)

  5. Lee Block says:

    This technique was not around in the late 80-90’s when I was racing…CCS/WERA etc. Seems that it would make the bike even more unstable since you can’t fully grip the bike evenly with your legs/knees and all the force is on your arms. Thus slight movements get transmitted into the bars.

    I remember first seeing it when Rossi started doing it, and as the article mentioned, might be more “monkey see monkey do” and there really hasn’t been any technical data to support any advantage. No that any of the world level riders are monkeys. I thought it was more a dirt track/offroad technique as …”oh crap, I’m in real hot so better put my foot out to dab”.

    Great article.

  6. CB says:

    In addition to helping with balance during braking, does it also help serve as a blocking maneuver on left turns? Provide some pause from the guy behind taking the inside?

    Also, does it help with cramping? I ride a GS and still need to shake a leg now and then.

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  8. singletrack says:

    Maybe these guys really just want to be off-road racers, where the real men are… :)

  9. Lionprince says:

    Once on tv I saw a cheetah at full speed and the narrator explaining while the shot was in slow motion of the cheetah using his long tail as a way of balancing himself in quick directional changes. It acts as a rudder or a way of counter balancing himself to make those hard quick directional changes and I immediately thought of Vale or Dovi using their legs to help them just before the corner. It really is interesting!

  10. Gabe says:

    I’ve seen, no joke, Douchecati riders doing the leg dangle in the canyons, usually going fairly slow

  11. Damo says:

    Rossi has said on several occasions that he first saw the technique when Kevin Schwantz used to do it. there is some old footage from the mid 80’s kicking around somewhere.

  12. alex says:

    This is race craft and I would not expect to get a straight answer from anyone.

    The most obvious advantage is psychological – if your bike is suddenly twice as wide in any corner not only can the people next to you be affected but the people attempting to late brake, early apex or late apex. It’s basically track side CB at it’s finest and it sticks with competitors the entire race. No one wants to run into another person because they will likely be penalized and or crash.

    Secondly your legs are some of the strongest muscles in your body and with the massive force of braking these bikes have you can transmit all of that into the bike itself in ways that may exaggerate a skid or make it difficult to maneuver. Halving the number of inputs on the pegs considerable reduces the force on the bike.

    A bike will ride itself just fine so transmitting less force not more force into it is usually the preferred method.

    Riders in MotoGP don’t just copy other riders style they copy other riders ideas and if it works for them they will use it.

    Lorenzo probably doesn’t do it because ultimately it’s not the fastest way around the race track and hes spent many many years perfecting his technique which includes overriding some of your bodies natural responses. Like riding the front brake etc.

  13. TC says:

    When is Myth Buster going to do an episode on GP Leg Dragging? I am sure there is an physical / mechanical advantage of doing it.

  14. tony says:

    all true! i often think of this when i’m riding, and do it sometimes. my brother never does, and he’s faster than hell. but then again, so am i. it seems to me it is the tightrope walker thing, also monkey see-do thing, as well as survival thing. i’ll do it in slow blind corners when i don’t want to drop the bike, using my my leg/ foot to as a third point of reference…oh, and welcome john orchard! man among men that guy!

  15. Old Boy says:

    I agree that several riders were doing this before Rossi ever put it on the world stage. From 2001-2005 you could see a couple of AMA Superbike racers doing this, most notable Kurtis Roberts. I used to think it was an old habit of dirt trackers until seeing it more widely used.

  16. Gritboy says:

    Using a leg for counterbalance to control a tight turn works for me, but I’ve never tried it a triple digit speeds.

  17. Lester. AUS . says:

    Finally some light , I’ve seen John O. at QLD Raceway n it looks sweet.
    It’s the tightrope thing for sure, I watched & worked out what a few kilo’s just outside C of G dos to cornering control when it looks out of control. I haven’t tried it on my ZX-10r at the track yet but at our cycleing training track I mucked around on entry’s into Hairpin & it wasn’t till I’ve starting using Cleats n shoes that I found out that without thinking I’ve checked my foot wasn’t locked in & my leg went out naturally as I turned in to the apex then back up on pedal & around I went online & smoothly.
    Holy shit I thought it worked… I also am thinking did it derive from Road Cycling that a lot of Moto riders do in there training . Cheers Happy Motoing in the New Year.

  18. Alec says:

    Kevin Magee was doing this in the 90’s. My explanation is that like a skater pulling in their arms to spin faster, the leg being pulled in at the point of turning helps to tip the bike into the turn. It’s just a controlled change of the centre of gravity in favour of the turn. A leg is pretty heavy and so it’s just a controllable item of ballast. I recall Valy saying he didn’t know why he did it but knew why others did.

  19. Thanassis says:

    Vale started doing it just to get rid of the presure of Gibernau. Then he just kept doing it and the rest followed without really knowing why. Vale’s point is that it takes all the attention of the (very) close following rider so it can ruin his pace, line, accuracy, almost everything. In the most demanding area of the corner, the entrance. Even if he expect that, still it is not possible to resist grabing some of his attention (by looking at it).
    Only riders who have trained in Supermoto can do it.
    And in road racing it doesn’t seem to be a good think. Under the presure of braking, with the leg out of the peg, all the presue goes to the bars -which is not a good think at all…