ADVrider

Go Back   ADVrider > Riding > The perfect line and other riding myths
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 08-31-2013, 12:40 AM   #931
Sprig
Gnarly Adventurer
 
Joined: Jun 2010
Location: Crossroads of Georgia
Oddometer: 119
Quote:
Originally Posted by henshao View Post
Countersteering does not rely on gyroscopic precession!...
Think about this: when driving a car, if you turn to the right ...
I'm thinking about a scene in the movie "Cars" where the old guy advises the young guy to turn left to go right...

The devil is in the details.
Sprig is offline   Reply With Quote
Old 08-31-2013, 01:12 AM   #932
DudeClone
Beastly Adventurer
 
DudeClone's Avatar
 
Joined: Nov 2010
Location: here, there, everywhere
Oddometer: 1,335
Quote:
Originally Posted by vfr700 View Post
I gave my old partner my Twist of the Wrist collection as he decided to start riding and picked up a new GSXR 750 (back in 2000) to learn on . A week later he asked me how often I countersteered, my initial response was Tuesdays & Thursdays, unless it was leap year.
__________________
bikes
DudeClone is offline   Reply With Quote
Old 08-31-2013, 01:13 AM   #933
DudeClone
Beastly Adventurer
 
DudeClone's Avatar
 
Joined: Nov 2010
Location: here, there, everywhere
Oddometer: 1,335
^ hey look i am counter-rolling
__________________
bikes
DudeClone is offline   Reply With Quote
Old 08-31-2013, 05:30 AM   #934
PFFOG
Richard Alps-aholic
 
PFFOG's Avatar
 
Joined: Aug 2005
Location: Western NY, further from NYC than 6 entire states
Oddometer: 1,925
OK here is something for both sides to argue about.

Thais is an excerpt from Motorcycle Handling and Chassis Design the art and science, by Tony Foale Considered the Bible of motorcycle dynamics by many.

First is explains in detail what initiates the turn. For those that feel they must know exactly how it works in order to do it. (have fun trying to consciously apply this while riding). And for those that claim you counter steer all the way through a corner it shows why normally you do not, but at a point turn in the direction you want to go.

And the point I have tried to make , at the end, the brain with visual and information from our cochlea, and semicircular canal (inner ear) process and adjust rapidly. Yes people run off corners, not because they don't know how to counter steer, but because they get scared and look for an out, and as soon as they turn their head to look away from their target, 1/2 of the brains input changes channel, and your brain steers you there. IMHO LOOKING WHERE YOU WANT TO GO is a better lesson than learning the dynamics of counter steering.

So here is Tony Foale's in depth analysis.

Initiating a turn
The basics
How do we actually initiate the turn, we have already seen that a moving motorcycle has an automatic tendency to stay upright? Do we lean first or steer first? If we were to turn the handlebar in the direction we want to go, both centripetal tyre force and gyroscopic precession of the front wheel would cause the bike to topple outward. Therefore, if we momentarily turn the bar in the opposite direction, then the centripetal tyre force and, to a much lesser extent, the gyroscopic reactions will cause the machine to
bank to the correct side. There are four main effects to be observed.
• A steering action to the right, will cause the machine to start turning right, and just as in a car,
centripetal tyre force will cause a lean to the left. This is the major banking influence.
• This steering action as we have seen, will also produce a small precessional tendency to lean the
machine to the left. This is a small effect when the wheels are on the ground, as shown later.
• Gravity will then initially augment the banking effect, but this will become less important as the tyre
cornering force builds up and balances the gravitational moment completely, when the bike reaches
the steady state lean angle.
Balance and steering 4-7
• The velocity of banking or roll rate will give rise to gyroscopic torques which oppose the rider’s
counter-steering input helping to steer the front wheel into the curve. This gyroscopic torque is in
opposition to the rider applied steering torque, and in fact balances most of his input and hence
works against rapid steering. However, without this “negative feedback” the bike would be rather
unstable and very hard to control, as we shall see.
These forces will also act on the rear wheel which, because it is rigidly attached to the bulk of the
machine, will tend to make the machine yaw into the curve. However, this reinforcing effect is secondary
to that of the front wheel. Steering rake and front-wheel trail, also help steer the machine into the curve
as the lean angle builds up. When we have established our correct lean angle, the processes for
maintaining balance, as described above, will come into effect and help keep the bike on our chosen
path.
We have seen, then, that a turn can be initiated by steering momentarily in the “wrong” direction.
Termed “counter-steering”, for most riders this action is accomplished subconsciously. In racing, riders
often make use of deliberate counter-steering to achieve the high roll rates necessary under those
extreme conditions. Briefly, it is the combination of gyroscopic moments and centripetal force that
requires this counter-steering action, we don’t have a choice in the matter. There are those that would
have us believe that counter-steering wasn’t known about until the 1970s. or ‘80s.. This is nonsense, it
is well documented that around the start of the 20th century the Wright Bros. were well aware that this
was the mechanism for turning a bicycle. In the early 1950s., whilst chief engineer at the Royal Enfield
motorcycle factory, Wilson-Jones did a series of tests with real motorcycles to investigate this further.
The results of these and some of his other experiments into steering geometry were published in
engineering journals.
However, counter-steering doesn’t explain how we can corner “hands-off”. Although, whilst it is possible
to do this, it is accomplished only with a lot more difficulty. So let us consider what happens if we try to
lean without being able to steer. As there is nothing solid for us to push against, the only way we can
apply bank is to push against the machine with the inertia of our own body. To lean the bike to the left,
we must therefore initially move our body weight to the right. The left leaning bike will now generate
camber forces from the tyres tending to lean both rider and machine over to the right, the roll rate will
again cause a gyroscopic steering torque which helps ensure correct balance. The initial bike lean to the
left might well be considered as a ‘counter-lean’, analogous to the ‘counter-steer’ of hands-on turning.
Anyone that has tried changing direction ‘no-hands’ will know that we have far less control over the
machine with just body movement available. The mechanisms involved with counter-steering produce
much greater response and more finesse of control.
So, we now have two possible methods of initiating a turn and it is interesting to note that in both of them
(banking and counter-steering) our physical effort is in the opposite sense to that which might be thought
natural. When learning we adapt quickly and the required action becomes automatic. It is these reverse
actions that require us to learn to ride in the first place. The required responses are clearly counter
intuitive. When learning most of us initially wobble about out of control until our sub-conscious latches
on to the fact that counter-steering and counter-leaning is the way to do it. Once the brain has switched
into reverse gear, it becomes instinctive and is usually with us for life, and we can return to riding after a
long layoff with no need to re-learn the art of balancing or steering.
In practice, we sub-consciously combine both methods, with some steering and some body motion. The
relative proportions by which we combine the two methods depend partly on riding style but also on
speed and machine characteristics. For example, a heavy machine with light wheels at low speeds
demands a different technique from that appropriate to a light machine with heavy wheels at high speeds
4-8 Balance and steering
and hence a different feel. However, humans adapt quickly and the correct technique soon becomes
second nature.

__________________
Tuscany 2010
Maritime Alps and Vosges

Richard
PFFOG is online now   Reply With Quote
Old 08-31-2013, 05:35 AM   #935
PFFOG
Richard Alps-aholic
 
PFFOG's Avatar
 
Joined: Aug 2005
Location: Western NY, further from NYC than 6 entire states
Oddometer: 1,925
More from Motorcycle Handling and Chassis Design the art and science, by Tony Foale

More detail
Having considered the basis of initiating a turn in fairly general terms, let’s now look at this very
important aspect in more detail.
Consider a racing bike approaching a corner and the rider needs to heel over as fast as possible. He
strongly applies counter-steer and the machine starts to lean over rapidly, but getting a quick roll
acceleration also means we need a quick roll deceleration. We start off upright with no roll velocity and
we end up at 45-50 degrees lean, again with no roll velocity. In the process the roll velocity must have
increased up to a maximum value somewhere around about half of the final roll angle, and then
decelerated back down to zero roll velocity at the final lean angle. So the whole lean-in process is not
just as simple as a bit of counter-steering followed by straightening out at the end. Basically, we use
counter-steer to lean the bike in, at about half way through the roll we have to remove it and possibly
give it some "pro-steering" to cause the roll deceleration.
For a long time those that read various motorcycle magazines may have been somewhat confused by
the rather conflicting “explanations” often given for this process. There would appear to be two
conflicting theories and the adherents of one seem to deny completely any possibility of validity in the
other. We might term these two theories
• Gyroscopic or precessional theory. Where it is taken as read, that at least the majority of the
lean-in torque comes from gyroscopic reactions.
• Steering out from under theory. Which basically assumes that as the front tyre steers out from
under the CoG., gravity will then continue the lean as the steering straightens up.
I imagine that most open-minded people interested in this subject would be inclined to the view that there
are probably some truths and untruths in both points of view with reality lying somewhere in a
combination of both. We shall see that this is indeed the actual situation, but we shall also see that the
physical mechanisms from either theory alone is capable of explaining the motorcycle lean-in. However,
neither theory alone properly explains all the observed phenomenon. Both theories however, require
that we use “counter-steering” i.e. the initial rider’s input is counter to that necessary for a very slow
speed turn.
The whole process of establishing a stable cornering attitude is extremely complex and to understand it
properly needs a mathematical explanation outside of the scope of this book, but the following is a
detailed description of the process using graphical rather than mathematical results from computer
dynamic simulations. In order to fully understand what’s happening some of the simulations represent
impossible situations, but are never-the-less useful. For example, in the first simulation we consider the
case in which the tyres produce no lateral force, thus leaving us with only gyroscopic reactions to lean
the machine. Another simulation is done with no gyroscopic effects, this approach allows us to clearly
see the individual forces and is useful to test the two theories above. The simulations allow us to
investigate the effects of parameter combinations that just aren’t possible with a real machine, and this
can provide valuable insights to the detail behaviour. All the simulations are for a bike travelling at 100
km/h, and the rider is aiming for a final lean angle of 44 degrees. The bike data is not for any specific
Balance and steering 4-9
bike but, except where noted, are typical of an average large capacity machine. Before tackling the
following, the reader is advised to read Appendix 4 describing the mechanisms of gyroscopic effects.
The following text is quite detailed and possibly tedious to read, but is included for those that want to
better understand the detailed mechanisms of the lean-in process.
__________________
Tuscany 2010
Maritime Alps and Vosges

Richard
PFFOG is online now   Reply With Quote
Old 08-31-2013, 05:38 AM   #936
hippiebrian
Beastly Adventurer
 
Joined: Jun 2012
Location: Long Beach, Ca.
Oddometer: 2,892
Quote:
Originally Posted by rbrsddn View Post
If it is so easy, why did that guy go wide in the corner on the Dragon and go flying over that vehicles hood??? Countersteering in a panic situation doesn't come naturally. You have to understand it to be able to use it when you need it most. And you are countersteering balancing on the pegs at a standstill. It doesn't " Kick" in at 5 mph.
Like I said earlier, the dude went wide in the corner because he was riding faster than his ability and experience were prepared for. Do that, and you'll screw up every time wether you know the physics of turning a bike or not.
hippiebrian is offline   Reply With Quote
Old 08-31-2013, 05:40 AM   #937
hippiebrian
Beastly Adventurer
 
Joined: Jun 2012
Location: Long Beach, Ca.
Oddometer: 2,892
Quote:
Originally Posted by rbrsddn View Post
If it is so easy, why did that guy go wide in the corner on the Dragon and go flying over that vehicles hood??? Countersteering in a panic situation doesn't come naturally. You have to understand it to be able to use it when you need it most. And you are countersteering balancing on the pegs at a standstill. It doesn't " Kick" in at 5 mph.
Okay, push your bike around your driveway and countersteer. At that slow a speed, countersteering will just make you drop your bike at worst, go the wrong direction at best.
hippiebrian is offline   Reply With Quote
Old 08-31-2013, 05:43 AM   #938
hippiebrian
Beastly Adventurer
 
Joined: Jun 2012
Location: Long Beach, Ca.
Oddometer: 2,892
Quote:
Originally Posted by farmerstu View Post
the saying is "you can't know what you don't know"
countersteering in the way any single track vehicle steers the instant you pick your feet off the ground. there is no "speed" at which it kicks in.
while looking where you want to go probably makes a rider countersteer it isn't going to do the job when there is no time to turn the head and look. when what's called for is a quick yank on the bars.
also push and pull should be equally easy. I.E. a sharp swerve and recovery should be automatic with either hand.
I can't help but think you are sure you know how to aggressively counteersteer but you really don't . like several people have said in this thread , they rode for years but only thought they knew what they were doing.

why are you so dead set on this not being important ?
I just have a hard time with people who teach new people how to ride filling their head with unnecessary information. There is enough for a new person to concentrate on when they are out there riding and practicing. Adding more information than necessary makes it not only more confusing and difficult but potentially more dangerous. Countersteering is a "nice to know" for those who have been riding for a while just to learn the physics, but unnecessary for a new rider.
hippiebrian is offline   Reply With Quote
Old 08-31-2013, 06:57 AM   #939
lnewqban
Ninjetter
 
lnewqban's Avatar
 
Joined: Jan 2012
Location: Florida
Oddometer: 290
Cool2

Quote:
Originally Posted by hippiebrian View Post
I just have a hard time with people who teach new people how to ride filling their head with unnecessary information. There is enough for a new person to concentrate on when they are out there riding and practicing. Adding more information than necessary makes it not only more confusing and difficult but potentially more dangerous. Countersteering is a "nice to know" for those who have been riding for a while just to learn the physics, but unnecessary for a new rider.
Counter-steering is more necessary for higher speeds, when turning a bike requires real force (some GP racers have bent handlebars); a realm very far from a new rider while riding like a new rider should.
Maybe we should teach a person to ride in simple terms with the caveat of later returning to us to learn counter-steering, before he/she becomes over-confident and stupid and tries negotiating that curve "riding faster than his ability and experience were prepared for".
Quote:
Originally Posted by PFFOG View Post
OK here is something for both sides to argue about.

Thais is an excerpt from Motorcycle Handling and Chassis Design the art and science, by Tony Foale Considered the Bible of motorcycle dynamics by many.

...............When learning most of us initially wobble about out of control until our sub-conscious latches
on to the fact that counter-steering and counter-leaning is the way to do it. Once the brain has switched
into reverse gear, it becomes instinctive and is usually with us for life, and we can return to riding after a
long layoff with no need to re-learn the art of balancing or steering.
................. However, humans adapt quickly and the correct technique soon becomes
second nature.


lnewqban screwed with this post 08-31-2013 at 07:09 AM
lnewqban is offline   Reply With Quote
Old 08-31-2013, 07:13 AM   #940
farmerstu
Gnarly Adventurer
 
Joined: Apr 2011
Location: Minnesota west central
Oddometer: 360
Quote:
Originally Posted by hippiebrian View Post
I just have a hard time with people who teach new people how to ride filling their head with unnecessary information. There is enough for a new person to concentrate on when they are out there riding and practicing. Adding more information than necessary makes it not only more confusing and difficult but potentially more dangerous. Countersteering is a "nice to know" for those who have been riding for a while just to learn the physics, but unnecessary for a new rider.
I don't think anyone here is saying you need to teach the physics of why a m.c. needs to countersteer to initiate a turn.
however,explaining that a bike has to lean in order to turn,and further explaining that in order to get the bike to lean you have to countersteer.
just saying look where you want to go and having a new rider figure it out from there borders on the criminal.
if it works for you,great. but please,please don't be teaching anyone else how to ride.

you don't know what you don't know. imagine a person born blind. sight can be described to them be any number of sighted people. but they can never really know what it is to see.

now we're off to Wisconsin for the weekend. hope you have a great labor day weekend as well!
farmerstu is offline   Reply With Quote
Old 08-31-2013, 07:37 AM   #941
DAKEZ
Beastly Adventurer
 
DAKEZ's Avatar
 
Joined: Mar 2007
Location: OR
Oddometer: 19,439
Quote:
Originally Posted by Sprig View Post

I don't really think I am a fool.
It was not my intent to ridicule you. I was only trying to help you understand that 1 MPH or 50 MPH if you turn a motorcycle you counter steer 100% of the time. It matters not how you made it happen… The FACT is it DID happen. If not you would have
1. Continued going straight or
2. Fell over.
If you are going to teach your Son (or anyone else) Why not teach him (them) the truth?

Quote:
Originally Posted by Sprig View Post
I've seen video of guys standing upon the seat and navigating to maintain center of lane. How is that counter steer thing working then?

Ask yourself: How did they change directions while standing on the seat?

Right answer: They initiated a counter steer.
__________________
“Watch out for everything bigger than you, they have the "right of weight"
Bib

DAKEZ screwed with this post 08-31-2013 at 07:46 AM
DAKEZ is offline   Reply With Quote
Old 08-31-2013, 07:39 AM   #942
DAKEZ
Beastly Adventurer
 
DAKEZ's Avatar
 
Joined: Mar 2007
Location: OR
Oddometer: 19,439
Quote:
Originally Posted by hippiebrian View Post
Countersteering is a "nice to know" for those who have been riding for a while just to learn the physics, but unnecessary for a new rider.

This is exactly WRONG and a good way to get people hurt or killed.
__________________
“Watch out for everything bigger than you, they have the "right of weight"
Bib
DAKEZ is offline   Reply With Quote
Old 08-31-2013, 07:59 AM   #943
Valker
Gnarly Adventurer
 
Valker's Avatar
 
Joined: Dec 2003
Location: Pampa, Texas
Oddometer: 288
Once again: counter steering is the ONLY way to turn any single track vehicle at any speed. There ARE
multiple ways to cause the bars to move other than with hand pressure. If you are passionate enough in your beliefs opposed to what I said, very carefully tack weld the steering head into the perfectly straight ahead position (I recommend a really junky old bicycle that only goes slow and full protective gear) and try to ride.
CAUTION: injury and/or death may suddenly occur, but a ride will not.
__________________
"Though no one can go back and make a brand new start, anyone can start from now and make a brand new ending." -Carl Bard
Valker is offline   Reply With Quote
Old 08-31-2013, 08:34 AM   #944
hippiebrian
Beastly Adventurer
 
Joined: Jun 2012
Location: Long Beach, Ca.
Oddometer: 2,892
Quote:
Originally Posted by DAKEZ View Post
This is exactly WRONG and a good way to get people hurt or killed.

How?
hippiebrian is offline   Reply With Quote
Old 08-31-2013, 09:10 AM   #945
Sniperx
Gnarly Adventurer
 
Joined: Jul 2013
Location: Socal
Oddometer: 254
http://www.youtube.com/watch?v=PgUOOwnZcDU

Thanks for putting that up. The above video actually put the whole thing solidly in my mind. Now that I know HOW it works and WHY you need to do...I can focus on really practicing it.

Just to make sure I have it.

There are three ways to turn a motorcycle. Crank the bars, reserved for parking lots and extreme low speed. Lean with little input on the bars (intuitive counter-steering) producing a long sweeping curve. And a true counter-steer...pushing the bar with the hand you want to turn towards....this initiates a lean faster and deeper, giving you the needed counter weight (I forgot how the vid refers to it) to overcome the bikes nature to bring itself upright again. This allows you to throttle through the turn and get around whatever problem may be occurring (curve, swerve, or etc). The video goes into more detail, but I think I've got the mechanics of the thing understood.... Right?
__________________
Motorcycles are like chlorine for the gene pool. 8/31/2013

Sniperx screwed with this post 08-31-2013 at 09:22 AM
Sniperx is online now   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 06:40 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014