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Old 07-03-2014, 03:25 AM   #1186
vortexau
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Quote:
Originally Posted by Klay View Post
That's a secondary effect. Countersteering works even if there are no gyroscopic effects.
Quite right. The machine pictured below requires counter-steering (actually- out-tracking) to be taken through changes of direction on snow.

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Old 07-03-2014, 04:08 AM   #1187
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Originally Posted by vortexau View Post
Quite right. The machine pictured below requires counter-steering (actually- out-tracking) to be taken through changes of direction on snow.


Phew, at least it doesn't have one of those dangerous front brakes.
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Old 07-04-2014, 07:27 AM   #1188
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Quote:
Originally Posted by JohnCW View Post
............. Watch a MotoGP racer going through a tight chicane quickly moving their body from one side of the bike to the other. With their arses completely of the seat during the transition point how much opportunity and time do they have to be consciously pushing on the bars? It's no where near as simplistic and one dimensional as some people make out. And no, I'm not just trying to stir up shit either.
Either consciously or unconsciously, MotoGP racer must counter-steer as much as all of us: there is no shortcut around that.
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Old 07-04-2014, 10:24 AM   #1189
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Originally Posted by lnewqban View Post
Either consciously or unconsciously, MotoGP racer must counter-steer as much as all of us: there is no shortcut around that.
By 'counter-steer' I'm assuming you mean rider input to the bars. With our terminology clear, this academic paper that appeared in the American Journal of Physics in 2000 does not agree with your statement. It concludes "Like many real-world processes, bike steering is a complicated combination of many different actions". This academic article is far more consistent with my own experience and observation, and the importance of body movement in steering a motorcycle. I'd certainly take more notice of it than Keith Code who apparently was the first to discover/observe the phenomenon of counter-steering as a young man (I've read this statement written by him). Someone should have told the Wright Bros not to worry, Keith will be on the case 70 years latter.

http://socrates.berkeley.edu/~fajans...eerBikeAJP.PDF

.

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Old 07-04-2014, 11:07 AM   #1190
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Quote:
Originally Posted by JohnCW View Post
By 'counter-steer' I'm assuming you mean rider input to the bars. With our terminology clear, this academic paper that appeared in the American Journal of Physics in 2000 does not agree with your statement. It concludes "Like many real-world processes, bike steering is a complicated combination of many different actions". This academic article is far more consistent with my own experience and observation, and the importance of body movement in steering a motorcycle. I'd certainly take more notice of it than Keith Code who apparently was the first to discover/observe the phenomenon of counter-steering as a young man (I've read this statement written by him). Someone should have told the Wright Bros not to worry, Keith will be on the case 70 years latter.

http://socrates.berkeley.edu/~fajans...eerBikeAJP.PDF

.
That article says that "hip thrust" steering is less effective than actively counter steering and that even "hip thrust" steering initiates a countersteer just not through the bars.

What was your point again?

The fastest and most precise and most efficient way to aim and steer a motorcycle is to countersteer. Especially at any speed above a crawl. To suggest a motorcycle racer is not countersteering is flat out wrong.
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Old 07-04-2014, 07:12 PM   #1191
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Originally Posted by Boon Booni View Post
That article says that "hip thrust" steering is less effective than actively counter steering and that even "hip thrust" steering initiates a countersteer just not through the bars.

What was your point again?

The fastest and most precise and most efficient way to aim and steer a motorcycle is to countersteer. Especially at any speed above a crawl. To suggest a motorcycle racer is not countersteering is flat out wrong.
So you just conveniently overlooked his calculation that by counter-steering through the bars alone required the rider to input 12 units of torque, but when the shoulder was dropped into a turn it required only 2 units of torque. That's 1/6th the effort, relatively little pressure to the bars. That doesn't seem to imply an ineffective practice to me at all. This completely aligns with what I experience on the road.

Did you actually even read the article? Regardless, I see the thread just reverting back to the same old "push left to turn left" being all there is to turning a motorcycle, and attracting morons like the previous poster, so I will leave you guys with it.
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Old 07-04-2014, 07:40 PM   #1192
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Quote:
Originally Posted by JohnCW View Post
So you just conveniently overlooked his calculation that by counter-steering through the bars alone required the rider to input 12 units of torque, but when the shoulder was dropped into a turn it required only 2 units of torque. That's 1/6th the effort, relatively little pressure to the bars. That doesn't seem to imply an ineffective practice to me at all. This completely aligns with what I experience on the road.

Did you actually even read the article? Regardless, I see the thread just reverting back to the same old "push left to turn left" being all there is to turning a motorcycle, and attracting morons like the previous poster, so I will leave you guys with it.

No one has said that shifting your weight doesn't assist in maneuvering the bike, but counter steering is the most efficient and effective way to turn the bike. Real world experience shows that with hands off the bars turing is vague and unwieldy.

The article says the same. Hip thrusts offer slower turn in. My experience is that it's also much less accurate.

Counter steering is how you turn the bike, shifting your weight is "english" added to enhance your technique.
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Old 07-04-2014, 08:35 PM   #1193
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Originally Posted by Boon Booni View Post
No one has said that shifting your weight doesn't assist in maneuvering the bike, but counter steering is the most efficient and effective way to turn the bike. Real world experience shows that with hands off the bars turing is vague and unwieldy.

The article says the same. Hip thrusts offer slower turn in. My experience is that it's also much less accurate.

Counter steering is how you turn the bike, shifting your weight is "english" added to enhance your technique.
One very last point before I go, I promise. Unless the term 'counter steering' is used the same way the guy in the article uses it, to mean rider input to the bars, consolidating every form of rider input into the very same name (counter steering) just makes for a confusing, and somewhat pointless discussion. Riders are interested in bar input, body position, peg weighting, etc. etc. things that can be worked into their riding technique. Saying all rider inputs produce counter-steering is useful to who? Certainly not me. The academic article recognizes that a lot of different rider inputs turn a motorcycle and the interaction between these inputs is not well understood. There will never be a universal relationship because the effort and rider inputs to turn a Moto3 bike bear no relationship to that of a Triumph Rocket III.

P.S. and why do you need to take your hands of the bars when you hang off more in response to a reducing radius turn to get the bike to tighten up? I don't, never take my hand of the bars, dangerous practice.

Finito.
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Old 07-04-2014, 09:08 PM   #1194
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-- Out-tracking gentlemen --



Gentlemen (and those who's behaviour should be more gentle), I fear when you ignore the term "out-tracking"; you can get more (and more) in disagreement about Rider Movement/s - and about Movement of the Front Wheel (and sometimes the position of the rear).



For a "single-track" vehicle to change direction, in most cases the Front Wheel has to be Out-tracked to a position outboard of the turn radius. Even when a normal four-wheeler takes a bend -- the front wheels take paths outboard of those taken by the rear wheels.

(Forklift Trucks, Skid Steer vehicles, Zero-turn lawn mowers, and Articulated Steering vehicles are exempt here because they do not employ solely controlled mechanical pivoting at the front.)

Returning to the "single-track" --- since these vehicles bank through a turn, out-tracking the front end positions the front outboard to the turn and induces the banking itself.

While body-english can be involved - along with even bouncing wheels into the air - "counter-steering" of the handlebars themselves remains the most positive rider input in moving the front wheel outboard.

Skid-steering of the rear wheel, as in speedway and flat-track riding (along with riding parallel along a dirt or grass slope) still involves some front wheel movement although throttle-movement can be the MAIN control for the direction taken.





And in all of this- the rider's body itself can be positioned to suddenly increase the banking angle, or to just reduce the banking angle. (see below)
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Old 07-05-2014, 04:47 AM   #1195
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Originally Posted by JohnCW View Post

P.S. and why do you need to take your hands of the bars when you hang off more in response to a reducing radius turn to get the bike to tighten up? I don't, never take my hand of the bars, dangerous practice.

Finito.
Taking your hands off the bars demonstrates the effectiveness of turning the bike by only shifting your weight. . It's not very effective.

It also eliminates your secret or unconscious counter-steering input to the bars.

When that decreasing radius turn comes up, I crank on the bars to lean the bike over more, if I feel like may run out of clearance I'll also slide off the seat. I am aware of doing both and aware of what each movement does.
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Old 07-06-2014, 10:13 AM   #1196
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Quote:
Originally Posted by JohnCW View Post
By 'counter-steer' I'm assuming you mean rider input to the bars. With our terminology clear, this academic paper that appeared in the American Journal of Physics in 2000 does not agree with your statement. It concludes "Like many real-world processes, bike steering is a complicated combination of many different actions". This academic article is far more consistent with my own experience and observation, and the importance of body movement in steering a motorcycle..........

http://socrates.berkeley.edu/~fajans...eerBikeAJP.PDF

.
Very interesting academic paper, John; thank you.
Nevertheless, I don't see how it does not agree with my statement.

When a racer starts hanging off left while still moving on a straight line and before braking to set an entry speed for a left turn, he must slightly steer left in order to counteract the natural tendency of the bike to turn right.

As he pushes the center of mass of the bike away from him, the bike slightly leans to the right, which tends to rotate the front wheel to the right (via trail effect).

When the rider goes for a quick flick (quick left lean) and applies clockwise torque to the bars (counter-steers to the right), that natural tendency mentioned above helps him and he needs to input less torque.

Once the bike starts leaning left, that natural tendency reverses and the racer must stop that over-steering effect.

The heavier the bike is respect to the rider, the less effective the hang-off is (and subsequent hip effect).
The faster the bike is entering that turn, the more torque for counter-steering is needed.

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Old 07-06-2014, 02:08 PM   #1197
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Thank you, people, for not quoting my dumbass comments. I'm going to go apply what I've learned here...
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Old 07-07-2014, 02:08 AM   #1198
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Originally Posted by JohnCW View Post
Watch a MotoGP racer going through a tight chicane quickly moving their body from one side of the bike to the other. With their arses completely of the seat during the transition point how much opportunity and time do they have to be consciously pushing on the bars?
how does that relate to conservation of momentum?

It's like ooching and rocking a boat - sure, you can run along the boat to get it to move the other way, but when you stop, the opposite happens. Nett result is no movement of the boat. Surely doing that to a bike is the same thing. Chicanes have a nett lateral movement though, which means moving your arse one one way then the other results in a positive energy input to the system - seems very odd.

On the other hand, what does speed of movement have to do with it - does a high speed chicane change the dynamics compared to a slow one, and are you, ipso facto, unable to negotiate a chicane if you nail your arse to the seat?
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Old 07-07-2014, 05:21 AM   #1199
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Go do some tire warming weaves on a very light bike, the sort you see riders doing as there are coming to the start line. Sort people do just before hitting the twisties with cold tires. Something the weight of a Moto3 bike that weighs about 80kg, a Moto2 about 125kg, or a MotoGP bike at 160kg.

Try doing these relative tight weaves just by left-right bar pressure alone with zero body input. Now try doing them primarily by throwing you hips from side to side, hands just loose on the bars for balance, letting the bars swing freely.

Anyone can go out and try this, don't quote textbooks or theory. Which way did you find the most effective at getting the bike to weave quickly and significantly from side to side in practice, rider initiated bar or hip movement?

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Old 07-07-2014, 06:24 AM   #1200
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Did we ever get to the bottom of this?
Nope, looks like we didn't.
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