Countersteering vs body leaning?

[bogan]

No the geometry is still bad. When the bike is iupright and balanced, the moment caused by a body hanging off it is relatively minor. even at standstill.
As opposed to when the bike is leaned over already.

yeh but if even a small moment makes it turn in whats the difference?

Point of order here...
Counter steering is the force that acts upon a rotating tyre, causing it to initiate a turn. The term 'counter' comes from the fact that the tyre must turn slightly in one direction, in order to initiate the turn in the opposite directiion.
What ever you do to effect this is known as counter steering, be it peg weighting, body shift or bar input.
Can we not refer to each as they are, not what they cause?

yeh thats what i was saying a few pages back, counter steering (physics) is different from counter steering (technique) where you consciously decide to push on a bar to start the turn, thats my take on it anyway.

[R-Soul]

Ahaaaaa......

Its easier to highlight the text you want to do stuff to, and then press "ctrl" and (B for bold or U for underline or I for italics)

does anybody know how to get a video into a posting? and how to upload a video as an avatar?

[R-Soul]

Point of order here...
Counter steering is the force that acts upon a rotating tyre, causing it to initiate a turn. The term 'counter' comes from the fact that the tyre must turn slightly in one direction, in order to initiate the turn in the opposite directiion.
What ever you do to effect this is known as counter steering, be it peg weighting, body shift or bar input.
Can we not refer to each as they are, not what they cause?

But there is no other way of initiating counter steering EXCEPT by pushing/pulling on the bars (or pushing and pulling on the wheels/forks). Peg weighting does not do this. It causes a moment on the bike in total to make it lean/fall over (as opposed to moving the front wheel out to cause the lean).

[R-Soul]

yeh but if even a small moment makes it turn in whats the difference?

Slow turning

Yeh thats what i was saying a few pages back, counter steering (physics) is different from counter steering (technique) where you consciously decide to push on a bar to start the turn, thats my take on it anyway.

Peg weighting does not initiate counter steering. It initiates LEAN. Slowly.

It does not cause the front wheel to steer sideways to make the bike fall over quicker. It merely topples the bike over. Slowly.

[schrodingers cat]

Its easier to highlight the text you want to do stuff to, and then press "ctrl" and (B for bold or U for underline or I for italics)

does anybody know how to get a video into a posting? and how to upload a video as an avatar?

Any of the You Tube videos give you an 'In-bed code' which you cut and paste into your reply.
You could load an animated GIF as an avatar but I don't think you can load a video file

[R-Soul]

Any of the You Tube videos give you an 'In-bed code' which you cut and paste into your reply.
You could load an animated GIF as an avatar but I don't think you can load a video file

Is that what the other guys have (the ones with moving avatars?) animated GIF's?

How do you load them?

I have also seen emails with moving pics on them - I presume also animated GIFs too, and always wondered how to put them in there..

[MSTRS:Me]

But there is no other way of initiating counter steering EXCEPT by pushing/pulling on the bars (or pushing and pulling on the wheels/forks). Peg weighting does not do this. It causes a moment on the bike in total to make it lean/fall over (as opposed to moving the front wheel out to cause the lean).

Sorry, but you are wrong.
The bike does begin to lean to the side you weight, BUT in doing so, the steering head reacts by turning outwards, which 'flops' the front tyre onto the side you have leaned towards, which in turn pulls the steering head etc back to the 'correct' side thereby the bike then turns in tha direction. It is EXACTLY the same as bar input. Just not as precise.

[MSTRS:Me]

Is that what the other guys have (the ones with moving avatars?) animated GIF's?

How do you load them?

I have also seen emails with moving pics on them - I presume also animated GIFs too, and always wondered how to put them in there..

Find an animation (Gif) you like, download it onto your hard drive, go to your settings page with the avatar field and 'insert' the file there. There is a size and Kb limit tho.

[schrodingers cat]

Is that what the other guys have (the ones with moving avatars?) animated GIF's?

How do you load them?

I have also seen emails with moving pics on them - I presume also animated GIFs too, and always wondered how to put them in there..

Google for them (Google image search). So long as it has the *.GIF extension treat it like any other file. You're quite used to moving *.JPG files, this is no different. PS - Not ALL GIF's are animated

I see this site supports doc gif jpeg jpg kmz pdf png pps psd swf torrent xls

To see what the others are using as their moving avatar, right click on one and select 'save as'

http://www.freefever.com/animatedgifs/motorcycles3.html

[Spearfish]

Hasn't the amount of rake got something to do with how quickly it leans or how far it goes for a given amount of counter steering? (and how fast( or how much force) the steering geometry returns to zero or straight)

The centre of gravity dictating to how much it needs to lean to resist tipping over itself with the centrifugal force generated? (high side).
Then its up tyre adhesion to avoid a lowside?
(not asked very well as usual)
Under a certain speed rider weight and strength can resist the very low centrifugal force, eg crawling trough a riverbed standing on the pegs (very upright).
Is a bike with a small amount of rake more or less prone to tank-slapping?

[onearmedbandit]

I explained it below. Hanging your body weight off does make the bike turn eventually. But it gives you about 5% of the steering available by counter steering. Its great if you only ever have to turn corners with 300 m radius (and makes life difficult if you want to change line in that corner).

But counter steering provides the ability to flick bikes from sides to side and turn 90 degree corners. Weight shifting does not. It also allows fro line changing in corners (by adjusting the bars again).

That is what I mean by weight shifting not giving you effective steering. Without counter steering, you have effectively NO steering.

While I'll disagree with the 300m radius number, as I know it can be done tighter, I wholly agree that the only effective method of getting a bike to turn is countersteer through the bars.

[bogan]

Slow turning



Peg weighting does not initiate counter steering. It initiates LEAN. Slowly.

It does not cause the front wheel to steer sideways to make the bike fall over quicker. It merely topples the bike over. Slowly.

yeh but its all relative, my point was with less rotational inertia a smaller moment is needed, so leaning, which does provide smaller moments would be enough.

Hasn't the amount of rake got something to do with how quickly it leans or how far it goes for a given amount of counter steering? (and how fast( or how much force) the steering geometry returns to zero or straight)

The centre of gravity dictating to how much it needs to lean to resist tipping over itself with the centrifugal force generated? (high side).
Then its up tyre adhesion to avoid a lowside?
(not asked very well as usual)
Under a certain speed rider weight and strength can resist the very low centrifugal force, eg crawling trough a riverbed standing on the pegs (very upright).
Is a bike with a small amount of rake more or less prone to tank-slapping?

yeh rake would affect the counter-steering force, the steeper the rake, the more torque is generated to lean the bike for a given bar push torque.
Think the trail would be more important in those situation you listed, but rake contributes also.

[Urano]

Hitcher was just taking the urine old son.
Your English is a hell of alot better than my Italian ...which is nil,but thanks for a bloody good laugh.
Footfingers is priceless

then teach me something and tell me how to explain it....!!!!!!!

Mind you this has raised more question than answer - I need to dive into google again....

i think that another interesting point of the question is that countersteering DOES NOT turn the bike.
it LEAN the bike.
which is way different.
if you apply the gyro rule to the front wheel, pushing the handle bar e.g. on the left end weight, creates a force through the fork.
imagine a big arrow going forward from the top of the left fork tube, and a big arrow going backward from the top of the right one.
those arrows going down through the fork, act on the hub, with an effect of a force pushing the rear side of the front wheel to the left, and pushing the front side of the front wheel to the right (imagine again the arrows)
we know that a gyro reacts to a force applied as it was applied "90° after, in the sense of rotation", so the arrow that pushed left the rear side of the wheel is "turned" 90° after, being on the top, and the other one is turned again 90° after, coming on the lowest point of the wheel.
so you have a big arrow pushing the wheel on the left from the top, and another one pushing on the right from the base.
that's it.
it simply LEAN the bike, it doesn't turn it.
what turns is the rear wheel, with the same principle of a spinning top, that turns when it is no more on a perfect vertical...

So weighting a peg or weight transfer will make a bike lean...?

not necessarily.
it depends on the speed and the virtual mass of the "gyro rigidity".
if it's enough you could come to an end where the weight displacement is so small in comparison the the gyro that the effect is smaller than the earth radius, so, actually, it would not turn...

[R-Soul]

Sorry, but you are wrong.
The bike does begin to lean to the side you weight, BUT in doing so, the steering head reacts by turning outwards, which 'flops' the front tyre onto the side you have leaned towards, which in turn pulls the steering head etc back to the 'correct' side thereby the bike then turns in tha direction. It is EXACTLY the same as bar input. Just not as precise.

Explain to me how weighting the peg can have any effect on the headstock angle? If you stand on your bike at rest, balanced, and you then weight a peg, I assume that the headstock does not change its angle. Unless its because you have jumped on the peg, and caused a bit of suspension give. The same principles apply when the bike is moving (plus a bit of gyrosopic effect from the wheels).

At a constant speed, the bike can be regarded as being at rest, and in equilibrium. But gently weighting the peg doesn't affect the headstock angle - it merely causes the bike to fall over to that side - and that is because (looking from the front) I believe that you are creating a cantilever effect by hanging your weight out.

Having said that, when you move your weight out, the weight of the bike should move the other way, to counteract your weight shift and keep the system in equilibrium, and the centre of mass of both (bike and rider) should stay in the same place.... so I am actually at a loss to explain how the bike turns under weighti shifting at all? Unles sits because of miniscule differences in friction? Anybody?

EDIT: I have thought about it again and I thnk you are right. Just like when you push//pull on handlebars, it causes a force to cuase lean to the wheel by gyroscopic precession. If you lean your body weight to one side, and teh bike to teh other, you are moving teh wheel, and it wil cause the wheel to move in a direction at 90 degrees to the rotation. The small rotation direction is the lean direction. So the reaction force could well be in the turn plane.

In fact by my own reasoning above, the weight shoft does nothing to cause the bike to fall over, since the centre of Mass (COM) of both bike and rider stays the same.

This leads me to believe that all (or most) turning from weight shifting (as little as there is) is also caused by gyroscopic precession acting on the front wheel to cause the wheel to turn in a direction counter to the direction the bike moves (i.e. "counter steering" - defined by the physics and not the technique).

Never let it be said that I dont admit when I am wrong.

[bogan]

Explain to me how weighting the peg can have any effect on the headstock angle? If you stand on your bike at rest, balanced, and you then weight a peg, I assume that the headstock does not change its angle. Unless its because you have jumped on the peg, and caused a bit of suspension give. The same principles apply when the bike is moving (plus a bit of gyrosopic effect from the wheels).

At a constant speed, the bike can be regarded as being at rest, and in equilibrium. But gently weighting the peg doesn't affect the headstock angle - it merely causes the bike to fall over to that side - and that is because (looking from the front) I believe that you are creating a cantilever effect by hanging your weight out.

Having said that, when you move your weight out, the weight of the bike should move the other way, to counteract your weight shift and keep the system in equilibrium, and the centre of mass of both (bike and rider) should stay in the same place.... so I am actually at a loss to explain how the bike turns under weighti shifting at all? Unles sits because of miniscule differences in friction? Anybody?

two ways, gyroscopic precesion, and trail (so yeh, you assumed wrong).Yip weight out one side casues bike to steer to other side, tipping CM into the corner.