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Old 09-04-2013, 09:10 PM   #1006
Klay
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Quote:
Originally Posted by Boon Booni View Post
Negative. Turning from a full stop you lean the bike with your feet before pulling away. If you were to keep the bike perfectly upright with your feet and pull away with the bars at full left lock, you would fall over to the right.

yes.
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Old 09-04-2013, 09:15 PM   #1007
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Originally Posted by hippiebrian View Post
Whenever I make a u turn from a stop, i turn the handlebars in the direction I'm going. Of course I lean the bike, otherwise I wouldn't turn, but that wasn't my point. My point is that countersteering does not work at all speeds.

Most of what we do on a motorcycle, steering wise, is done without thinking. It's the same things we did on a bicycle without knowing what we were doing. That is my point.
Countersteering works at all speeds except for zero speed. If you're steering without thinking, you may react badly in a panic situation.

After a lean has been established through countersteering, you do indeed steer in the direction of the turn. At any speed.

Many people make the mistake of thinking that countersteering doesn't work at slow speeds because it feels different than at speed due to the attenuated gyroscopic effects at slow speeds.

Unsurprisingly, the laws of physics don't change just because you are riding your motorcycle slowly.

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Old 09-04-2013, 11:21 PM   #1008
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Quote:
Originally Posted by Boon Booni View Post
Negative. Turning from a full stop you lean the bike with your feet before pulling away. If you were to keep the bike perfectly upright with your feet and pull away with the bars at full left lock, you would fall over to the right.












I guess all of these rider's courses, including the CHP rider's course, are teaching the wrong way to do slow speed turns.
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Old 09-05-2013, 12:31 AM   #1009
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Extreme example of countersteering. Seeing is believing. The track is flowing LEFT. This dudes handlebar is almost at a full RIGHT lock steering because he is PUSHING LEFT so damn hard (and drifting the rear wheel and counterbalancing his body because of it). He's going fast too, you can't do this unless you're hauling ass and staying on the throttle utilizing the gyroscopic effect to stay upright. His leg is also exerting the smallest amount of force on the ground that's helping him to widen his center of gravity and keep him upright.

If he chops the throttle, he either catch traction and high side or lowside if off balance. If he lays on too much throttle he'll break too much traction and lowside spinning his rear. In essence, he's using the throttle in conjunction with small handlebar inputs to control the lean angle (which in turn controls how wide or tight his turning is).
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Old 09-05-2013, 12:56 AM   #1010
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Goes to show you...countersteering at higher speed, turn the bars with the turn at low speed. Wether you know it or not!
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Old 09-05-2013, 02:10 AM   #1011
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some light reading

http://mae.ucdavis.edu/~biosport/jkm/bh_papers.htm
http://ruina.tam.cornell.edu/researc...stablebicycle/

to those who keep talking about gyroscopic effects, please explain why a bike with no gyroscopic effects still behaves in the same fashion.

Quote:
The purpose of this work was to try to achieve understanding, and then relate that understanding to experience and practice. Current belief is that you need trail and possibly spin momentum for self-stability. Not true. That you need a tilted steer axis or front steering for self-stability. Not true. That gravity makes the front wheel steer to the side of a fall if trail is positive. Not true. This is not a recipe for a better bike, but I bet we can improve recumbent handling. And I bet there are bikes just as good as today’s, if not better, that will be built once folks have a better appreciation of the real physics.
http://www.cyclelicio.us/2011/bicycle-dynamics/
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Old 09-05-2013, 04:07 AM   #1012
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Jesus fucking Christ, I share the road with some of these people!
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http://advrider.com/forums/showthread.php?t=949341
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Old 09-05-2013, 04:17 AM   #1013
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Quote:
Originally Posted by hippiebrian View Post
[
I guess all of these rider's courses, including the CHP rider's course, are teaching the wrong way to do slow speed turns.
I think you're confused. No one said you don't steer into a turn once leaned over. You counter steer to initiate the lean. Once leaned over you steer into the turn.

You don't have to counter steer if you're turning from a stop and lean the bike with your feet. But watch most noobs, they guess the lean angle wrong, and the first thing they do is correct, by, counter steering.

Here's another example. If you are in a leaned over turn to the left. The front wheel is pointed left. If you want to tighten the turn you turn less to the left. Turning less to the left is counter steering. When you turn less to the left the bike leans further over, then you turn more to the left to balance at the new lean angle and continue turning left.
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Old 09-05-2013, 06:41 AM   #1014
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Beyond Counter Steering.

Quote:
Originally Posted by simonpig View Post

.
Of course you are right about the risk of high side or rear wheel catching up to the front but finding the balance is the art of sliding.
Another factor illustrated here is look where you want to go and you'll go where you are looking.
That at least seems to be a constant most of us agree on.

Once the rear wheel describes an arc wider than that of the front wheel the dynamics change.
(see recent post that mentioned out tracking and had a nice diagram - the above shot is the opposite to out tracking)
The gyroscope effect is still there but the countersteering effect is no longer evident.

Increased throttle tightens the turn.
Turn right (push left) widens the turn.
(don't try to tighten the turn with steering effort alone or you will explore the high side event)

Traction adjustment is via weight distribution and peg pressure
Weight outside peg to increase traction on rear
Weight forward to reduce push (understeer, front slide).
Forward and back body weight distribution can be effective but tends to limit the left right counterbalance options to adjust for the other inputs in all but the fittest, most skilled and agile riders.

If you want to examine the mechanics to the point of confusion refer to Tony Foale and consider how his slip angle calculations are altered once the wheel(s) start(s) to slide.
Don't be confused about the exteneded leg supporting the vehicle making it non mono track - it's just a feeler and a balance aid.

If you tell me the shot is of you the year you won the #1 plate I'm going to be very embarrased and outed as an Internet crack pot .
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Old 09-05-2013, 06:46 AM   #1015
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Quote:
Originally Posted by Boon Booni View Post
I think you're confused. No one said you don't steer into a turn once leaned over. You counter steer to initiate the lean. Once leaned over you steer into the turn.
Or more accurately: The front wheel steers into the turn. You don't need to make any input to the motorcycle if you are happy with the speed and turn radius.

Hippie, give it up. Inuitive "but it feels like it works this way" is always going to lose to explanations that are fully grounded in the laws of physics.
It's like the plane on the treadmill brainteaser. Yes the plane does take off, like any mechanical engineer will tell you.
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Old 09-05-2013, 06:50 AM   #1016
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Quote:
Originally Posted by simonpig View Post
....................Extreme example of countersteering. Seeing is believing. The track is flowing LEFT. This dudes handlebar is almost at a full RIGHT lock steering because he is PUSHING LEFT so damn hard (and drifting the rear wheel and counterbalancing his body because of it). He's going fast too, you can't do this unless you're hauling ass and staying on the throttle utilizing the gyroscopic effect to stay upright. His leg is also exerting the smallest amount of force on the ground that's helping him to widen his center of gravity and keep him upright.

If he chops the throttle, he either catch traction and high side or lowside if off balance. If he lays on too much throttle he'll break too much traction and lowside spinning his rear. In essence, he's using the throttle in conjunction with small handlebar inputs to control the lean angle (which in turn controls how wide or tight his turning is).
I respectfully disagree about sustained counter-steering in this case.

We only turn when we steer that front tire in (or pretty close to) the direction that we want to go.
While turning, the bike must be banked to be in balance, more as faster and tighter we turn.
Counter-steering is only one trick to bank the bike into that balance or lean angle (only one corresponds to each combination of speed and radius of turn).
There is no way around that, there is only one Physics.

Now your picture:
That rider is steering while banking, the bike is in balance: the combined lateral and weight forces are pointing from the CG to the line that connects both contact patches.
The only difference with a sport bike on asphalt is that the front tire is leaning less and slipping more and that the rear tire is skidding (respect to the direction of movement, even if it is rolling) and way out of line with the front tire.
It is all about helping that front tire lead the direction of the circular trajectory in conditions of very poor traction: note that the rotation of the rear pushes that front tire toward the inside of the turn.
He adopted that position by a combination of counter-steering and rear brake (only until getting into that position), then, he steered the front and slid the rear.

.....or so I believe.

This link explains how tires get deformed while gripping on asphalt:
http://www.dinamoto.it/dinamoto/8_on...umatii_eng.htm


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Old 09-05-2013, 10:14 AM   #1017
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You're right about the dynamics changing once you initiate a drift, but to get into that drift state that you have to countersteer and that's the point I was making.

Once you're in a drift, you don't have to push as hard since, as you mentioned other forces come into play to control and balance the bike.

Quote:
Originally Posted by Rucksta View Post
Of course you are right about the risk of high side or rear wheel catching up to the front but finding the balance is the art of sliding.
Another factor illustrated here is look where you want to go and you'll go where you are looking.
That at least seems to be a constant most of us agree on.

Once the rear wheel describes an arc wider than that of the front wheel the dynamics change.
(see recent post that mentioned out tracking and had a nice diagram - the above shot is the opposite to out tracking)
The gyroscope effect is still there but the countersteering effect is no longer evident.

Increased throttle tightens the turn.
Turn right (push left) widens the turn.
(don't try to tighten the turn with steering effort alone or you will explore the high side event)

Traction adjustment is via weight distribution and peg pressure
Weight outside peg to increase traction on rear
Weight forward to reduce push (understeer, front slide).
Forward and back body weight distribution can be effective but tends to limit the left right counterbalance options to adjust for the other inputs in all but the fittest, most skilled and agile riders.

If you want to examine the mechanics to the point of confusion refer to Tony Foale and consider how his slip angle calculations are altered once the wheel(s) start(s) to slide.
Don't be confused about the exteneded leg supporting the vehicle making it non mono track - it's just a feeler and a balance aid.

If you tell me the shot is of you the year you won the #1 plate I'm going to be very embarrased and outed as an Internet crack pot .
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Old 09-05-2013, 10:30 AM   #1018
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Some people here states that you don't have to countersteer when you have feet on the ground, or when you push your bike. Isn't that because it's no longer a single track vehicle as soon as your feet are involved?
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Old 09-05-2013, 10:39 AM   #1019
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Yeah, the system becomes a tripod.

I say stay on the pegs and balance/counterbalance all the way down to 0 mph. One of the few only reason to be putting your foot down is to initiate a turn in a tight space like a wheelie pivot turn, or a slide pivot turn. Trials guys never put their foot down.



Quote:
Originally Posted by aferiksson View Post
Some people here states that you don't have to countersteer when you have feet on the ground, or when you push your bike. Isn't that because it's no longer a single track vehicle as soon as your feet are involved?
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Old 09-05-2013, 11:11 AM   #1020
Rucksta
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Quote:
Originally Posted by simonpig View Post
You're right about the dynamics changing once you initiate a drift, but to get into that drift state that you have to countersteer and that's the point I was making.

Once you're in a drift, you don't have to push as hard since, as you mentioned other forces come into play to control and balance the bike.
Yes all true.

Another technique as mentioned a post or two ago in a is to break the rear loose either with rear brake, down shift or a combination of both.
Once the rear is sliding you lean into the turn (let the bike fall in that direction a waggle of the bum on seat helps ensure the rear steps out in the desired direction),
apply throttle untill you balance the rear spin with the rear slip angle and drive into the turn.

This will tighten the turn and eventually lead to the back wheel overtaking the front until correction is made with the bars turning to the outside of the turn (turn into the skid)
No actual countersteering involved to initiate or sustain the turn.
In fact the "countersteering " or oposite lock action widens the turn

There is a little more to this argument with rear wheel gyroscopics - maybe we can touch on that later.

Another way to initiate drift is to approach a turn two thirds to the outside and give a quick jab at the bars (countersteer)
If the jab is forcefull enought the front will break out before it turns out and the drift can be set up with throttle to push the front end and break the back loose.

If I'm not feeling quite that brave or commited a combination of a quick jab at the bars and a stab at the front brake will achive the same result.

Combining the jab. stab and a harsh downshift with a bit of rear trail brake to moderate the downshift can acheive good results.
With some rear trail brake I can keep the engine loaded ready to respond and break traction (spin) on the rear by releasing the brake pedal.

I like a dry clutch and find the recluse clutch counter productive but that could be due to sucky rear brakes.

I find riders who are adept at these techniques can drift the whole way through a turn smoothly instead of having to face that nervous point post apex where you transition from a normal entry into a roosting / sliding exit.
The transition point is where you are most likely to experience the high /low side event so setting up the tranition on entry when the bike is upright reduces the chances of either.(unless you run out of grunt or find a sticky bit and hook the rear when cranked over.

So yes countersteering to induce the slide is a valid technique but there is more than one way set up for a drift.
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