I have worked with a bunch of pro lvel riders, such as Doug Polan, Ty Howard, David Anthony, Aaron Yates, And many more the only reason is that some of these guys are a little off and they do whatever they need to to feel comfortable going into a highspeed turn, whether it is from a different background to thinking it helps slow them down they are all different and have different reasons for doing things like that!!!

 

if youre trying to slow down, why not use your right foot to hit the rear break?

 

Bikes are hard to turn at the speeds they go - Mick Doohan said once that you have to use your whole body to turn a bike at speed, or it'll just go straight..........I think Rossi is using the leg to get more wind resistance on the inside, to help him turn it..............
but it's just a guess...................

 

he does it so he can corner low and air out the boys a the same time...

i heard it takes a second or two off your lap times