Racing Question per se

[SoCalMike]

Ok, so watched my first MotoGP race yesterday. Somewhere in Portugal. Got a question.

In MSF course the rider coaches stressed that even though it is instinctive to put a knee out in the direction you are turning, it does nothing for you. They kept telling people to keep thier knees firmly against the tank.

Now watching racers, and reading on here, everyone is talking about dragging a knee. My question is this. Does dragging a knee create some kind of support, so you can lean the bike past the point at which the tires lose traction? Why is it done? Or is it simply a measure for how far over you are able to lean the bike in a turn?

[87gsxrnut]

. . . everyone is talking about dragging a knee.

Yeah, well, you don't really need to be dragging knees on the street. Really.

Does dragging a knee create some kind of support, so you can lean the bike past the point at which the tires lose traction?

I suppose it can support somewhat, but that usually happens unplanned (with me anyway). Ummm . . . when tires lose traction fully, you are on your a$$.

Or is it simply a measure for how far over you are able to lean the bike in a turn?

Now you are getting somewhere! Usually used for measurement, but also it allows you to have the center or gravity more to the left or right, allowing the bike to be more upright, thus allowing more speed through the turns without having the bike scrape parts, or having it run out of traction.

Hell, someone else could probably explain it better than me.

- Nut

[Freakinout]

When you are shifting your weight off the center of the bike (in the direction of the particular corner you are going through) the knee just kinda sticks out from there. Measurement is the biggest part of why you see the motogp guys doing it.

On the street people will try to get their knee down, just to say they've done it. Has a lot less to do with actually needing it for a measurement tool.

[prekarious1]

street riders do it because they think it makes them look cool. The best is when they do it without the proper gear on and it is not needed for that turn at all. You will see some people practically climbing off of their bikes to try to put the knee down, stay away from them, if they are your friends just stay back far enough that you know you can stop to help them out if/when they mess it up. I have been known to move my body to the inside to let me carry more corner speed, but I will not lean so far as to need to put my knee down on the street.

[Crazy1ear]

In the movie Faster, the racers talk about how the whole knee dragging started in GP racing. There's a bit of a debate as to who actually did it first, but I believe it was Kenny Roberts Sr.

He used to race on dirt ovals where they drag their feet through turns and carried it over to road racing.

The reasons pointed out here thus far may all be valid, but as Kenny Roberts (and others) explain it, the main reason for putting down a knee is to lower the center of gravity of the motorcycle. By getting your butt off the seat and getting a knee out, you move that much weight to the side and down low. This allows you to carry more speed through a turn with a taller lean angle.

Do not attempt without proper gear and only on a track. Back in the day Kenny Roberts et all used to place layers of duct tape on their leathers (before the days of the knee puck) to let the leather slide on the pavement. Leather is extremely sticky on the road and scraping a knee on asphalt is a good way to pull yourself off the bike... not to mention the pounding on the knee!