--On Friday, November 1, 2002 8:01 AM -0800 Tom Sheraden <[EMAIL PROTECTED]> wrote:
I've seen this argument a few times, and each time it's struck me that perhaps it's just a question of semantics, all adding up to the same thing.
In this case, it wasn't. Keith Code asserts, most vigorously, that one simply cannot steer a motorcycle without using the handlebars. I took exception with that and tried to make a case for it. :-)
My take is that leaning shifts your center of mass on the bike, which changes the force vector on the steering head, which causes the front wheel to change direction - particularly at lower speeds where those small forces have less (cycloscopic?) inertia to overcome.
Via what force? If the steering system deflects, something deflected it. I assert it was gravity acting on the bike due to the displacement of the COG. Take a bicycle and stand it upright, holding it by the seat. Lean the bike left and right with your hand and observe how the steering head deflects. It isn't gyroscopic effects.
If the steering head were unable to shift direction (i.e., respond to the change in force vector), would leaning changing the direction of the bike? I don't think so. If it would, I think that would constitute real "body steer," but I sure don't understand the physics that would create that effect.
Nope. If the steering head were immobile (not the case on the no BS bike), then you simply couldn't steer the bike. When you caused it to lean, it would fall over.
Does shifting your center of mass on the bike assist in "hand-actuated" turns? I think so, because you're using the change in center of mass as a turning force in addition to force you exert with your arms on the handlebars. However, that alone does not, in my opinion, constitute body steering.
Body steering, in my opinion, is the use of peg pressure and/or body wieght shifting to cause some change in the motorcycle's direction. Whether or not this is done in conjunction with countersteering is irrelevant to the argument at hand. The argument I was attempting to refute was that "there is no such thing as body steering". I agree with you otherwise. :-) Take care, Mike -- Michael Weaver (706)542-6462 [EMAIL PROTECTED] Engineering Services EITS University of Georgia, Athens Ga. )O( Public PGP key: http://www.arches.uga.edu/~weaver/pgp.html
