<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by R6Racer:
...if I'm not mistaken, riding in someone's draft also causes them to slow up slightly by creating additional drag...
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Actually, it's the opposite:
When two bikes (or cars, or whatever) are drafting, both of them end up going faster than a single bike.
Here's why: At speed, two things cause aerodynamic drag -- the air hitting the front of the bike is responsible for most of it. But there's also the air coming back together behind the bike. This turbulence forms a vacuum that essentially is trying to suck the bike back where it came from.
These two effects are constant for any given speed.
Now, think of the two bikes, nose to tail, drafting. Obviously, the bike in the rear doesn't have much of the air in front to deal with, so he can certainly go faster than normal.
But at the same time, the lead bike doesn't have the normal vacuum area behind his bike, since the air is continuing to stream past the rear bike, rather than swirling around directly behind his own bike. This actually gives him (the leader) a slight speed increase as well!
Now, of course, the difference is not nearly as apparent as the one the drafting bike is experiencing, but it's there. This is why a pack of riders freight-training together can almost always catch a lone rider on the faster tracks. It happens all the time at places like Hockenheim.
This effect is even more noticeable in Stock Car racing. Because of the shape of the stock cars, when they get up on somebody's rear bumper, the turbulence between the two cars is virtually eliminated, so two or more cars, nose to tail, can run much faster than a single car...
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I'm not joking. And don't call me Shirley.