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Old 02-05-2013, 06:15 PM   #303
ibafran
villagidiot
 
Joined: Apr 2007
Location: chicagoland
Oddometer: 1,281
Well. It's been a cuppla days and nobody jumped on this recently posted video. So, in the interests of accuracy and hoping that future riders/readers may not be lead astray with popular myths, I will attempt an improvement. Somebody...hold my beer.

Countersteering is what is done to the bike to initiate lean in the desired direction in order to maintain balance and/or course. The handlebars are considered to be the most optimal and reliable device to affect this action.

At about the 45sec mark, the video says that countersteering kicks in at about 22mph. This is an error. Countersteering works at the very moment that the bike must be balanced when other modes of balance disappear. Like when the rider's feet come off the ground and no longer have any input into keeping the bike upright and on course. Perhaps the perfect example of this is during a "slow ride" race where 2 budds try to cover the same distance as slowly as possible without touching (dab) a foot to the ground. The last budd to cross the finish line wins. At these very slow speeds, riders often have to move the handlebars very quickly almost to the lock to get the front wheel under the tipping bike and bring the bike back upright. Sometimes the clutch needs to be let out a little to pick up enough speed to get the front wheel under the bike fast enough to save the tip-over.
If anyone doubts this, ride a bicycle as slow as possible to see the same effect without risking a tip-over for the motorbike.

At about the 1:30minute mark, the video states that body lean will "steer" the bike. This is largely an error. Leaning the body to one side might cause the bike to drift in that direction, or not, dependant on a variety of conditions. The biggest problem with this statement is proving that the body is the sole input that causes the steering. Leaning the body to the right may cause the arm to push the right handlebar grip slightly which does in fact steer the bike but may not be sensed by the rider. This leaves the rider thinking that the body lean steered the bike which in no way is the actual fact.
To test how well 'body lean' actually steers the bike, a rider might set the throttle lock or cruise control and ride hands-free in a safe environment. If the parking lot is big enough and empty enough, the rider could try for a figure eight and see how repeatable and controllable his 'body lean' steering might be.
That said, lots of riders/stuntas have 'body steer' down to a fine art and can do it hands-free while standing on the pegs demonstarting the skill in an empty lot. It is not much done in traffic as using the handlebars is the method of choice in that scenario most of the time.

Later in the video (7min?), it is noted that the bike goes in the direction in which the front wheel is pointed. Which it does only after the proper lean is initiated by countersteering and the front wheel has returned to a near central position to carve the desired arc. Nothing is explained about how the bike is righted from a left arc and turned into a right arc.

The video repeats these errors. Kudos to the amature videographer's bravery for taking his shot. Perhaps he will edit his effort for a little more accuracy? Caveat:ymmv

It is dang hard to describe all the stuff that goes into keeping a bike balanced and on trajectory. Most riders cannot accurately describe bike steering any better than they can accurately describe how they walk. Riders interested in this stuff can try reading the works of Tony Foal. Larry Grodsky (rip) of "Stayin' Safe" fame wrote a column on body steer and trying to ride the Blue Ridge Pkwy hands-free. I took my shot at riding the BRP hands-free and got a long way at the legal limit before having to reach for the bars on 2 corners. Both of those were decreasing radius lefts. "The Upper Half of the Motorcycle" os another good read that addresses some of this.
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ibafran screwed with this post 02-05-2013 at 06:29 PM
ibafran is offline   Reply With Quote