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Old 01-31-2013, 10:00 AM   #301
i_4ce
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Here is why you can’t rely on bike experience to completely translate to riding a motorcycle.

Sure it’s true that bikes need counter steering to initiate the turn like a motorcycle, but it is very slight. The rider of the bike may not be completely aware of it. They may even be attributing it more to body movement.

Secondly, unlike a motorcycle, bikes will most often coast through a turn. Since the bike is slowing, the rider will need to constantly steer INTO the turn to stay upright. They have never had the experience of needing to tighten the turn by adding counter-steer during the turn. What effect this has on a motorcycle is that the riders coast through turns to keep their line. When throttle is required, like from a stop making a left or right turn, the rider will run wide because they do not know how to tighten their line when throttle is applied.

I think knowing counter-steering and believing in counter-steering is required to be a good motorcyclist.

2 things to practice:
1) The swerve test like how MSF does it. You just do a quick jab forward on the right grip. Amazingly you’re now headed to the right. Another quick jab on the left grip and you’re going straight again.

2) Go through a curve adding throttle enough to slowly increase speed. Add a smooth continuous counter-steer to keep the bike in line and prevent running wide.
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Old 01-31-2013, 08:42 PM   #302
Clydascope
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When this thread started I didn’t fully understand countersteering but then found this video:

http://www.youtube.com/watch?v=s8M_7fBR63Y

Nearly every time out I practiced what I learned. I commute 5 days a week on the bike.

Tonight around 8:00, about a mile from home, going 45 mph, a van traveling in the opposite direction turned into a parking lot on my right, crossing directly in front of me.

A push on the bars, some hard braking; for a split second both tires locked up, off the brakes and I cleared his rear bumper by about a foot.

To everyone who helped me understand more about countersteering...


Thank You, Thank You, Thank You!
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Old 02-05-2013, 06:15 PM   #303
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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
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Old 02-06-2013, 07:56 AM   #304
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^^^^ Thread over!
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Old 02-06-2013, 09:20 AM   #305
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Quote:
Originally Posted by ibafran View Post

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.
countersteering to lean the bike while moving, and moving the bars around to keep your balance while not moving (or barely moving) is not the same physical phenomenon. One is conservation of angular momentum, the other is simply balancing.
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Old 02-06-2013, 11:27 AM   #306
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Originally Posted by bh321 View Post
countersteering to lean the bike while moving, and moving the bars around to keep your balance while not moving (or barely moving) is not the same physical phenomenon.

Actually, YES it is.
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Old 02-06-2013, 12:58 PM   #307
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Originally Posted by DAKEZ View Post
Actually, YES it is.
^^^^ Thread not over yet!

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Old 02-06-2013, 01:22 PM   #308
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Originally Posted by DAKEZ View Post
Actually, YES it is.

no, it's not


at low speeds, the bike leans primarily due to the torque about the longitudinal axis produced by the slip angle, which was introduced by the countersteer.

as you increase speed, you get an increasing amount of lean inducing torque from the conservation of angular momentum when you turn the front wheel. (gyro effect)

both happen any time the bike is moving.

when not moving, slip angle and angular momentum don't mean doody, and by turning the bars you're simply moving the contact patch around from the bike/rider CG - ie balancing.

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Old 02-06-2013, 05:05 PM   #309
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Originally Posted by pretbek View Post
^^^^ Thread not over yet!

The Kinematics and Dynamics of Rotation is a thread for all seasons.

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Old 02-06-2013, 05:51 PM   #310
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Originally Posted by bh321 View Post

when not moving, slip angle and angular momentum don't mean doody, and by turning the bars you're simply moving the contact patch around from the bike/rider CG - ie balancing.
OK so try this. When you are balancing and need the bike to tip to the right, turn the bars to the right and see what happens. You either fall over or you put your foot down to keep from falling over. Your gyro angle has already been shot down (for the most part) in this very thread.

You are mistaken (wrong) be it through ignorance, willful or otherwise it doesn't matter... You are still wrong.

Now go fetch some beer.
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Old 02-06-2013, 07:07 PM   #311
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Jeezuz guys, give it up! Ian, Iowa
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Old 02-06-2013, 11:35 PM   #312
Klay
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Quote:
Originally Posted by ibafran View Post
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.

effect

Quote:
Originally Posted by ianbh View Post
Jeezuz guys, give it up! Ian, Iowa

Never!
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Old 02-07-2013, 01:52 AM   #313
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[QUOTE=Klay;20668028]effect




I'm pretty sure it would be "affect".

You want to "affect" the action to bring about the desired "effect".

Here is an example from the interweb:

"Gender may affect the action of garlic oil on plasma cholesterol and glucose levels of normal subjects."

http://www.ncbi.nlm.nih.gov/pubmed/11340102
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Old 02-07-2013, 03:38 AM   #314
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I read somewhere that the speed at which countersteering comes into play is directly affected by the type of oil being run in the motor... dyno or synthetic.

Yup.
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Old 02-07-2013, 04:55 AM   #315
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Originally Posted by Barry View Post
I read somewhere that the speed at which countersteering comes into play is directly affected by the type of oil being run in the motor... dyno or synthetic.

Yup.

Yeah, and if you use Slick 50, the bike is unrideable!
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