formergixxer said:
I like the way kenny roberts said it, the knee was basically so you can actually control your weight in one place and the bike itself, allowing you to steer the bike with the rear wheel and be confident in it.
that's right! this is the ORIGINAL reason for knee-dragging. it was a practice roberts adapted from dirt--and the knee actually supported weight! it wasn't just a feeler or a guage. while having your knee down far enough to drag probably does have some effect on composite lean angle (thereby lessening the degree of lean angle needed), it's probably residual and as such is not the primary reason for doing it. the real reason is it's part of a steering mechanism as stated above.
it's the confusion of these things that screws up most riders. probably the more important concept to understand and implement is the adjustment of composite cg, i.e., getting the weight off the bike. but most think that it's the damn knee that's so important, and so they make huge personal satisfaction investments in getting that knee down. since, of course, it's easier to get the knee down by hanging off the bike, these "knee" junkies start hanging off. and then this is where you start seeing the puke ugly form that a lot of amateurs (and even some pros) sport: torso upright and shoulders squared perfectly across the center of the tank, back twisting around like they're trying to go ass forward, butt hanging off the bike, and THE KNEE DOWN! YAY! ...not.
Lee Parks has a ton of diagrams of this problem point in his book
Total Control. the next time you're thinking you want to hang off the bike, remember, it's not the knee. it's all about weight distribution, reduction of lean angle, and traction management. you invite all kinds of problems if you have the kind of form described above.
the next time you watch a pro race check out where those guys' torsos are. look at where the inside shoulder is positioned/pointed. look at the outside arm. almost without exception, those guys' body weight is greatly shifted inside, butts and shoulders are in-line, and outside arms are stretched across the tank--elbows even resting on the tank.