From: randy@ninja.megatek.uucp (Randy Davis)
Subject: Re: Countersteering a shafty
Reply-To: megatek!randy@uunet.uu.net
Organization: Megatek Corporation, San Diego, California
Date: Tue, 18 Aug 1992 17:32:06 GMT


  First off, you HAVE to countersteer to turn ANY two-wheeled conveyance
when the two wheels are aligned in the same track.  With that said:

In article <1992Aug17.201252.21909@webo.dg.com> x1sdup@esparc19.NoSubdomain.NoDomain (Stephen Dupre) writes:
[...]
| For traction reasons, the rider should not be 'rolling on the throttle' in
|a turn because this causes the rear suspension to extend (most shafts) and
|therefore decreases traction (less rubber on road).

  Wrong...  The contact patch (amount of rubber on the road) doesn't change
nor does the amount of traction change.  The lifting of the rear end caused
by the torque effect of a shaft causes the center of gravity of the bike to
LIFT - if you are in a turn, this overbalances you, since, to turn a motorcycle
requires you to balance the weight of the bike (trying to fall inward) versus
centripetal "force" (really simply intertia) which is trying to make the bike
fall outward.  Traction - the sum amount of lateral force the tire/road contact
area is able to withstand without sliding - is the same for a chain or a shaft
bike, reguardless of lean angle of the bike or speed.

|  So it's best to set a speed going into a corner
|and maintain it.

  Different explanations, but I agree with this.  When I owned a 1983 V45
Sabre (NICE bike, but some of the WORST "torque effect" I've ever experienced),
you HAD to maintain a constant throttle, no matter what it was, or it would
either squat (rolling off the throttle) or raise (increasing throttle), thus
requiring you to instantly change your lean angle or change your cornering
line more than you might want, because of the changed center of gravity.

|  Chain drive rear suspensions squat during acceleration.

  Not noticable on any chain drive bike I've ever ridden, including the one I
have now.  Where have you observed this?

|It's still probably not advisable to 'roll on' in a corner with a chain drive
|but it would have less adverse reaction than a shaftie.

  It is no problem to roll-on the throttle in a corner with a chain bike, as
long as you have enough traction to handle the cornering forces in addition to
the added acceleration.  (All you MSF graduates remember your traction circle?)
In fact, its quite enjoyable to crack the throttle a little bit and start
spinning the rear tire at the exit to a corner...

|  Countersteering should
|be OK unless the rider is either shifting or adjusting the throttle in the
|turn or has a suspension problem.

  Countersteering is more than OK - you simply can't turn without it, whether
you are on a shaft-drive motorcycle, a chain-drive motorcycle, a BICYCLE, or
any OTHER two-wheeled vehicle where the wheels or aligned in one track...
Shifting or adjusting the throttle might affect how MUCH input you have to
give to countersteer, but you have to do it irreguardless of the make, model,
or your riding style...

Randy Davis				UUCP: randy@megatek.com
ZX-11 #00072 Pilot			      megatek!randy@uunet.uu.net
DoD #0013			 	      ucsd!megatek!randy