Question for the racers based on behavior I've seen on MotoGP

[bluepoof]

Since watching MotoGP this season, I'm seeing Stoner and Rossi in particular (but some other racers, too) put a foot out like they're going to skim the ground right before entering a turn.

The weird thing to me is that the bike looks very unstable after the racer does this.  I can't fathom the advantage.

Can someone explain?

[miles]

Rossi did it first, and everyone reasoned that if he does it (and he's the GOAT) than it must confer some advantage.

[RRdvark]

I have never seen a good explanation and I think it looks dumb.  I wish they would stop.

[dark_isz]

Interesting article on the flailing foot phenomenon.

http://motomatters.com/opinion/2009/07/22/the_truth_behind_the_rossi_leg_wave.html

[DogBoy]

Because its gangster.  

[Kneescrubber]

It's an air brake.

[mellow_gold]

Interesting article on the flailing foot phenomenon.

http://motomatters.com/opinion/2009/07/22/the_truth_behind_the_rossi_leg_wave.html

Good article. Thanks!

[RRdvark]

After reading the article it looks like it is time for him to find a new trick...maybe throw both legs over the windscreen high-chair style to get the front end of the Ducati planted...

[Hotbrakes]

I think there's a few factors in it.  While none of them could show any advantage, when you're on top of the world and every thousandth of a second counts, any advantage possible helps.

My theories-
1.  Psychological as stated in the article.  You make a larger silhouette and become harder to pass which is difficult to do already at that level.
2.  When braking to the absolute max, attempting to defy the laws of physics, having just a couple pounds a couple inches over keeps the motorcycle upright as the rider begins to turn.  This keeps the front tire more centered with the largest contact patch.
3.  Prevents early turn in and a ruined line.  By having one additional piece to move in helps delay the turn in point and prevent an early apex which will ruin your race very quickly.  A bad line in one corner could take half a lap to recover from.  The leg out slows the rider's entry process keeping them from turning early when the adrenaline is pumping.

[black hills]

I don't know the why, what, how of it but I can tell you if it had a negative affect on lap times they wouldn't be doig it

[Blunder]

Can someone explain?

The same reason Rossi adjusts his junk every time he leaves the pit lane.

[The Toecutter]

2.  When braking to the absolute max, attempting to defy the laws of physics, having just a couple pounds a couple inches over keeps the motorcycle upright as the rider begins to turn.  This keeps the front tire more centered with the largest contact patch.
3.  Prevents early turn in and a ruined line.  By having one additional piece to move in helps delay the turn in point and prevent an early apex which will ruin your race very quickly.  A bad line in one corner could take half a lap to recover from.  The leg out slows the rider's entry process keeping them from turning early when the adrenaline is pumping.

motorcycle racing is a ballet of physics, so this doesn't make sense.  shifting the leg shifts the cg away from the center of the bike/rider in to the corner tending to cause it to not want to stay upright and leading to early turn in.  now if you said they hung their leg to the outside of a corner it would make sense.

 

[Dan K]

I think there's a few factors in it.  While none of them could show any advantage, when you're on top of the world and every thousandth of a second counts, any advantage possible helps.

My theories-
1.  Psychological as stated in the article.  You make a larger silhouette and become harder to pass which is difficult to do already at that level.
2.  When braking to the absolute max, attempting to defy the laws of physics, having just a couple pounds a couple inches over keeps the motorcycle upright as the rider begins to turn.  This keeps the front tire more centered with the largest contact patch.
3.  Prevents early turn in and a ruined line.  By having one additional piece to move in helps delay the turn in point and prevent an early apex which will ruin your race very quickly.  A bad line in one corner could take half a lap to recover from.  The leg out slows the rider's entry process keeping them from turning early when the adrenaline is pumping.

I always thought it was to widen the area covered by the racer to make it harder to pass...but I guess it shifts weight even farther away from the center of gravity, like an early hanging off?  Who knows.  I'll read the article now...

- Dan

[Mr Sunshine]

It moves the weight from more center of the bike to even more onto the front end.  Those tires require a ton of downward pressure to make the tire work so it is very possible this helps out.

[sammyseaman]

It moves the weight from more center of the bike to even more onto the front end.  Those tires require a ton of downward pressure to make the tire work so it is very possible this helps out.

Ding ding ding! We have a winner  

[Scoop]

The human foot is the heaviest part of the body.  That's actually the origin of the term "lead foot" in reference to automobiles.  By moving the heaviest part of the body out and away from the bike, it creates a triangle formed of the bike, the leg and the track.  Applying Euclidian geometry to analyze the Pythagorean implications, it can be seen that mass shift acts on the otolith in the utricle on that side of the head.  This in turn, creates a false perception that one is already in the turn.  The resulting proprioceptive reaction puts the muscles of the eyes in an anticipatory position, optimizing the riders position into the turn.  This allows the rider to brake later because the body believes that it's already in the turn.  Simple physics and physiology, really.......

[scottzilla]

Wow.  Just wow.

[Blunder]

The foot is the heaviest part of the body? Maybe on those young and in shape like these GP jockies, but what about some of the fat heads we've got around here?

[bluepoof]

The human foot is the heaviest part of the body.  

Isn't it the head?  

[DogBoy]

New corner entry technique.