(Please visit one of our advertisers)

No donations or subscriptions are required

   OR   
   
Subscription choices:
Board Karma = 40  (3488 positive of 3870 votes is 40 %pts higher than a neutral 50%)
All Things (Safety Oriented) Motorcycle   
Username:
Password:
Save Password
Forgot your Password?

You can the entire collection of Safety Tip articles in a 33 Megabyte PDF Portfolio

 All Forums
 Motorcycle Safety
 Contrary Opinions
  Questions RE: Tip 233: Slow-Speed Countersteering?
 Questions RE: Tip 233: Slow-Speed Countersteering? Yes!
Member Previous Topic Discussion Topic Next Topic  

JanK
Male Junior Member
76 Posts


Ljubljana, Ljubljana
Slovenia

BMW

F650CS
Peer Review: 1

Posted - 08/22/2012 :  6:04 AM                       Like
Continuing discussion from http://www.msgroup.org/forums/mtt/t...PIC_ID=14198 in an associated thread:

I submit that at low speeds the counter steering input is lost in other inputs, but counter steering is still needed to initiate a turn, to transition between turns and to end a turn. The reasoning is slightly long, so please be patient.

Check out the video at https://www.youtube.com/watch?v=HuRlxpC9l-g (and ignore the unnecessarily rude introductory text). The quality of the video is not great, but the section between 1:15 and 1:25 clearly shows what the rider is doing. He is not touching the handlebars at all! Instead he moves his centre of gravity (COG) towards the inside of the desired turn and the bike slowly starts to turn in that direction.

The physics behind it is relatively simple and completely consistent with what was written in post http://www.msgroup.org/forums/mtt/t...PIC_ID=14026. Incidentally, the video essentially replicates the experiment described in the post, in which neutral steering has been shown to be easily achievable. If the rider does not need to hold the handles to keep the bike in a constant radius turn, he is by definition in the region of neutral steering.

Part of the conclusion of the post was:

quote:
So if you move your COG to the right of the symmetry line while riding in a straight line, the motorcycle will lean to the left and the combined COG should remain vertically above the wheels. If the ideas in this discussion apply to your bike, you should have then have to press the left handle to keep the motorcycle going in a straight line.


The post did not go into detail about what causes this effect, but the explanation is straightforward. When the bike leans to the left, two things happen. As a result of the motorcycle geometry, the head wants to turn in the same direction as the bike is leaned, i.e., to the left. The other effect of the left lean is that the contact patch of the front wheel moves to the left of the centreline. The drag from the front wheel is thus offset to the left. Both of these combine to create a steering torque to the left, which needs to be counteracted by pushing on the left handle to keep the bike running straight.

When you let go of the handlebar this steering torque to the left is not counteracted. The handlebar rotates to left, the bike acts as though you have pushed the right handle, thus initiating a counter steering turn to the right. The torque that can generated with this method is not high, so it is only possible to make long turns and the method is useless for "real" riding. But, as demonstrated, under some circumstances it is possible to use only body steering to steer the bike.

Moving on to behaviour at low speeds. Counter steering at low speeds is easily proven by an experiment that I just performed and that anyone can replicate. Since it is hard to overcome conditioned responses and movements by a rider sitting on a bike, one needs to consider the bike on its own.

I took the bike to a flat tarmac surface. Engine was turned off, gear was in neutral, side stand was up. I stood about 30cm to the left of the bike, held the left handle in my left hand and placed my right hand on the handle behind the pillion seat. The right hand was used to propel the bike forward. Apart from that I tried to make sure that the right hand made as little lean corrections as possible, it was mostly there to catch the bike if it started to lean to the right too much. If it leaned to the left, it would rest against my hip. Then I started pushing (pulling) the bike and walking along it until the speed was high enough to stabilise the bike and it was possible to take the left hand off the handlebar for a short time. The speed was slow walking pace, I'd estimate 2-3 km/h, almost an order of magnitude less than speeds where counter steering supposedly starts.

I then pushed the left handle forward with my thumb (not my palm or hand) to prevent any inadvertent lean corrections and to keep the steering torque low. I did three such runs and invariably the sequence of events was exactly as in "proper" counter steering: the front wheel turned to the right, the bike immediately started turning to the right and simultaneously leaning to the left. After around two or three paces the torque on the handlebar induced by the left lean was high enough to overwhelm the steering torque provided by the thumb. The handlebar turned to the left, the bike went into a left turn and eventually leaned against my right hip. At no point in the run have I had to pull the bike towards me, as I would have needed to, had the bike leaned to the right.

To exclude any effects from possible slope of the terrain I did three runs of the mirror experiment along the same path. I stood on the right side of the bike, used left hand to propel it and right thumb to press the right handle forward. The results were, as expected, the mirror version of the results of the previous experiment. Front wheel turned to the left, the bike leaned to the right, the front wheel eventually turned right and the bike ended up resting against my left hip. Again at no point in the run was it necessary to pull the bike towards me to keep if from falling.

There's one more experiment that I've performed, that can be reproduced by anyone and that may shed some light on what happens at low speeds. Imagine a gentle right turn. You can take the turn by keeping your body's vertical axis aligned with the motorcycle vertical axis. You can also take the same turn by keeping the bike completely vertical and only leaning your body, thus leaning the combined COG into the turn. For both methods to work it is necessary to counter steer by pushing the right handle. In the first case until your and bike's lean settles at the appropriate value. In the second case until your lean settles at an appropriate value. In both cases the combined lean angle is exactly the same for the same speed in the same radius turn.

At high speeds you use the first method: lean with the bike or lean slightly towards the inside of the turn. Because counter steering is the only effective way to steer at high speeds and because the steering torque is speed dependent, you have to actively and noticeably push the handle for quick steering. At low speeds the required counter steering torque is so small (remember, I used my thumb in the experiment) that it gets lost in other, relatively large movements of hands that are required to keep the balance at low speeds.

What I suspect happens is that the rider applies counter steering torque and moves his COG inside the turn. Alternately, as we've seen in point A, he can move his COG to the inside of the turn without providing torque on the handlebar, and the motorcycle will by itself provide the counter steering input. In both cases, is is the counter steering that initiates the turn. Because the momentum is relatively low due to low speed, the bike does not self-stabilise, as it would at higher speeds. Instead it starts to fall inside the turn, which is then compensated by increasing the speed or increasing the steering head angle by controlling steering torque. I suspect that the transitional speed between the self-stabilising mode and unstable mode is what corresponds to James' mention of the transitional speed between counter and direct steering, the 6-10 MPH, that depends on the geometry.

Incidentally: I have a very hard time imagining that in a slow speed right turn you need to rotate the handlebar to the left to make the bike stand up and go left, which would be true, if direct steering worked! Is it not true that to stand the bike up at low speeds you need to steer into the turn? If so, how is that different from exiting a corner at high speeds, where you start the transition to a straight path by pushing on outside handle, effectively steering into a turn?

So in conclusion: I understand the need to keep information overload for new riders low. In this context it may be appropriate to make a simplification (with clearly presented caveats) and say that there's a sharp speed boundary above which you use counter steering and below which you use direct steering.

However, as soon as you go into more detail about real motorcycle dynamics, the simplified picture is in my view simply wrong. Based on the results of experiments, I am firmly convinced that counter steering is the only method of initiating a turn at any speed.

It is, of course, quite possible that there's a flaw in the low speed counter steering experiment. If so, I would like to hear about it. Even better, it will take only 5 minutes of your time to repeat the experiment (perhaps with a helper or two to help catch the motorcycle and to push it along). If you do so, I would be very interested in the results.

And finally, for those that still doubt that counter steering works at low speeds, there's an experiment that you may perform, if you're willing to risk the crash of your bike. Get into a stable slow speed right turn. Now give the right handle a hard shove without moving the rest of the body. If the direct-steering-at-low-speeds were true, you would make a quick transition from a right turn to a left turn. However, I predict that you will crash to the right! That is why I will not perform this experiment on my bike.

James R. Davis
Male Administrator
17284 Posts
[Mentor]


Houston, TX
USA

Honda

GoldWing 1500

Posted - 08/22/2012 :  8:09 AM Follow poster on Twitter  Join poster on Facebook as Friend  
quote:
So in conclusion: I understand the need to keep information overload for new riders low. In this context it may be appropriate to make a simplification (with clearly presented caveats) and say that there's a sharp speed boundary above which you use counter steering and below which you use direct steering.


With that in mind, let's simplify. (Your explanation was masterfully presented, by the way. Bravo!)

In the macro (practical) reality we riders experience, it is certainly possible (and how we normally perform a slow speed turn) to turn our handlebars counterclockwise when we wish to make a left turn, and vice versa. That is, there is no NEED to attempt a clockwise turn before allowing the bars to actually move counterclockwise. It is sufficient at slow speeds we provide a single steering input (counterclockwise torque) and the bike will, as a result, adopt a path of travel to the left.

You said "I submit that at low speeds the counter steering input is lost in other inputs ..." and I agree with that part of your statement.

It has been said that the centripetal force generated at slow speeds is insufficient to offset the affect of gravity as an explanation of why the bike's momentum does not keep the higher portion of the bike in place while the tires roll out "from under the CG". But words like 'insignificant', 'insufficient', 'small' are not the equivalent of 'nonexistent'. There is, of course, some amount of centripetal force existent any time a bike's direction of travel is changed.

But properly characterizing things as 'insignificant' and 'insufficient' means that we can (and normally do) ignore those things as we maneuver in our practical reality, as you illustrate with your comments about body weight shifting to steer. Interestingly, the same example shows that you can ignore relatively large centripetal forces at higher speeds as well if you offset them. However, in the spirit of keeping it simple, at slow speeds you can actually completely disregard them.

If we can ignore the relatively trivial amount of centripetal force at slow speeds, then I am hard pressed to agree that they 'cause' a change of direction.

What I am convinced of is that at slow speeds we can make a left or right turn with a single steering input attempting to turn the handlebars in the direction of the desired turn, and that calling it a direct-steer maneuver is appropriate. At higher speeds, we can make a left or right turn with a single steering input attempting to turn the handlebar in opposition to the desired direction of travel, and call it a counter-steer maneuver.


Go to Top of Page

The Meromorph
Male Moderator
834 Posts
[Mentor]


White House, TN
USA

BMW

R1100RT

Posted - 08/22/2012 :  1:06 PM
Wow, I have always thought that the 'true' situation in low speed steering was similar to JanK's excellent analysis here.
I also agree with the point expressed by both JanK and James that the simple explanation used by James is both effective, and safe for all riders, and much easier to follow for beginning riders. Which is why I've never tried to propound JanK's analysis myself. In fact I think the situation in low speed steering is even more complex than JanK's analysis mentions with multiple effects acting simultaneously, but the characterization that the counter-steering effects are 'overwhelmed' by the other effects is a clear and appropriate simplification.

I have continued privately to consider very slight counter-steering as one of the inputs to my own low speed steering, partly because having that 'mental model' allows me to transition a conventional low speed turn into a 'counter-leaning' low speed turn seamlessly when appropriate. I have found myself to have better control, and a tighter available turning radius at very low speed, on the large and very heavy bikes I seem to ride these days, when I use counter-leaning.
I don't advocate counter-leaning as a general technique for low speed riding, but I believe it to be a useful and effective technique for some riders and machines.
Go to Top of Page

BennyRayRiddle
Starting Member
7 Posts


Beverly Hills, CA
USA

(None)

Posted - 08/30/2012 :  1:36 PM
quote:
I submit that at low speeds the counter steering input is lost in other inputs, but counter steering is still needed to initiate a turn, to transition between turns and to end a turn.
...
So in conclusion: I understand the need to keep information overload for new riders low. In this context it may be appropriate to make a simplification (with clearly presented caveats) and say that there's a sharp speed boundary above which you use counter steering and below which you use direct steering.
I agree with your premise, but disagree with your conclusion.


Imagine a rider slowly traveling a straight forward, but wobbly, path and the rider wishes to make a sharp right hand turn. The rider either "over-corrects" a left hand wobble or "under-corrects" a right hand wobble to initiate the change in lean angle before fully rotating the bars into the turn. A rider who has no or incorrect knowledge of the nature of motorcycle handling can easily miss the initial over-/under-correction and therefore believe that their rotating the bars into the turn is the entire turning process instead of just the second part of the turning process.

Reinforcing the delusion of direct steering at low speed is both dangerous as JanK's proposed experiment clearly demonstrates ("Get into a stable slow speed right turn. Now give the right handle a hard shove...") and counterproductive to slow speed skill development as The Meromorph's post also demonstrates. The correct thing is to help the student recognize the deviation from normal balancing inputs that precedes the turn-in.

Edited by - BennyRayRiddle on 08/30/2012 3:30 PM
Go to Top of Page

JanK
Male Junior Member
76 Posts


Ljubljana, Ljubljana
Slovenia

BMW

F650CS

Posted - 05/09/2013 :  5:38 PM
I believe I have further proof that slow speed countersteering not only exists. It is as essential for bike control at low, as it is at high speeds.

I have spent a lot of time at the proving ground doing PLP. The course includes a figure-8 in a standard motorcycle size 7m x 14m rectangle with cones set 7m apart. Once I could do the figure-8 well enough, including setting the cones to 6m apart, the distance for mopeds, I started making a circle and three quarters around each cone, testing bike's behaviour and isolating effects of inputs: throttle, clutch, steering,...

Once the turns got tight enough to start running into the steering lock, the bike sometimes wouldn't come out of the turn... I would look in the correct direction, do all the right things with the body and hands. Instead of the bike following the focus and my commands, it stayed in a tight circle.

The only way I could get out of it was to accelerate. If I didn't, and kept the body and everything else stable, it would keep going in a turn and I would only press harder against the lock. By the time I had realised what was going on and had accelerated out of the situation, I was already out of the course, approximately perpendicularly to the longer side at approximately midway of it.

As I investigated further, I found out that if I backed off a bit from the steering lock, by an amount depending on the speed, body position,... everything would function normally. As long as I was able to turn the handlebar by a certain amount into the turn I was in, I was able to initiate the change of direction. I usually ran into the lock for parts of a second during that initiation.

If I was at full lock and turned the handlebar towards the outside, the motorbike dove into the turn, not get out of it. It became necessary to add throttle to keep from falling.

I assure you, I was not trying to perform a dip, merely trying to get out of a turn.

How is this behaviour compatible with the direct-turn at low speeds theory?

This should be an easy experiment to replicate. Please do so and report, I would be really interested in the results.

[Added:]

After the transition was initiated, I did have to turn the handlebars towards the other turn to complete the transition. And this ties in beautifully with the "if it were countersteering, it would mean two inputs".

The second input at low speeds is indeed direct steering. But if there is no first countersteering input, the effect of a "direct steer" (as a first input) is actually a counterstering input that drives the bike into the turn, not out of it.

Yes, there is a difference between behaviour at low and high speeds. At high speeds the geometry, inertia,... put the bike in a mode where you need to maintain the initial countersteering input throughout the turn. An extreme example of this is a transition in a fast chicane.

At lower speeds the same physics puts the bike in a state, where the bars simply do not move quickly enough on their own. Thus they need a second input to speed up the steering head angle change to set the new course/roll angle.

Edited by - JanK on 05/09/2013 6:09 PM
Go to Top of Page

JanK
Male Junior Member
76 Posts


Ljubljana, Ljubljana
Slovenia

BMW

F650CS

Posted - 06/17/2014 :  6:53 AM
Lately I've been doing a lot of PLP. I've also acquired a camera. And it dawned on me that I could combine the two to finally put to rest the debate over whether countersteering exists at low speeds.

So I invite you to watch two short videos on YouTube, https://www.youtube.com/watch?v=GAHvbZtwyr8 and https://www.youtube.com/watch?v=clL28VDyaeg.

The videos provide unequivocal PROOF that not only does countersteering exist at low speeds, but also that direct steering is NOT necessary to make slow speed turns.

The location was our official proving ground, which you can find on https://www.google.com/maps/@46.025...ata=!3m1!1e3.

The motorcycle was in the first gear and the throttle in idle. The speedometer needle didn't move throughout the whole exercise, meaning that speed was around 6km/h, a fastish walking pace. The radius of the turns was around 3 metres.

In both videos you can first see a left turn, accomplished by exclusively pushing the left handlebar, then a right turn, accomplished by exclusively pushing the right handlebar. At no point in any of the turns was the handlebar manually turned into the direction of the turn, instead a countersteering torque was exclusively applied throughout the turn to control the turn.
Go to Top of Page

James R. Davis
Male Administrator
17284 Posts
[Mentor]


Houston, TX
USA

Honda

GoldWing 1500

Posted - 06/17/2014 :  7:40 AM Follow poster on Twitter  Join poster on Facebook as Friend  
Below is the test pattern painted on the ground as part of the MSF's training range layout.



I suggest that you cannot make that turn on a two-wheeled motorcycle using counter-steering.

It is obvious, as your videos demonstrate, that counter-steering CAN be used at very low speeds to make a lazy (WIDE) turn as there is a modicum of centripetal force that exists with any deviation from a straight line path of travel.

But to suggest, as you have, that counter-steering input is essential at slow speeds simply ignores the fact that most of the time, regardless of your speed, you need the motorcycle to take a path of travel that *you* want it to take as opposed to the path that it will take on its own based on a balance of steering input, centripetal force, gravity, and steering geometry.

Impressive camera work, by the way, used to prove your point.
Go to Top of Page

JanK
Male Junior Member
76 Posts


Ljubljana, Ljubljana
Slovenia

BMW

F650CS

Posted - 06/17/2014 :  9:31 AM
Just after finishing the videos I rode the motorcycle for regular maintenance, so I cannot try the turn you described until one week from now, when I'll set up the cones with the dimensions you mentioned.

But I predict that it will be possible to do the turn.

If you check out page 27 of http://www.mzp.gov.si/fileadmin/mzp...m_izpitu.pdf, you'll see dimensions of the figure 8 that we need to complete to pass the riders' exam.

Today I also tried (for the first time and without using the camera) navigating the figure 8 using only countersteering. I was able initiate the turn and complete one 270 degree turn around one cone, but could not make the transition between one turn and the next. Note that this was without any practice at all! If I practiced, I'm almost sure I could complete the whole exercise using only countersteering. We'll see in a week.
Go to Top of Page

johncrosby
Male Senior Member
256 Posts


Sevenoaks, Kent
United Kingdom

BMW

GSA 90 Anniversary

Posted - 06/25/2014 :  6:24 AM
Really enjoyed the very clear write-up. One of the hardest things for me to master was the transition from counter-steering speed to direct steering speed and vice versa.

After a long ride I still have a tendency to feel that low speed turns are awkward, with my brain screaming at me that I'm doing something odd. I have to consciously tell myself the next slow turn, U-turn, junction turn is slow enough to merit direct steering. It's frankly annoying as everything else regarding bike steering is beautifully intuitive and smooth when you have understood counter-steering. Am I the only fool who finds low speed steering annoying after hours happily counter-steering?
Go to Top of Page

scottrnelson
Advanced Member
6887 Posts
[Mentor]


Pleasanton, CA
USA

KTM

990 Adv, XR650L

Posted - 06/25/2014 :  10:02 AM
quote:
Originally posted by johncrosby

Really enjoyed the very clear write-up. One of the hardest things for me to master was the transition from counter-steering speed to direct steering speed and vice versa.

After a long ride I still have a tendency to feel that low speed turns are awkward, with my brain screaming at me that I'm doing something odd. I have to consciously tell myself the next slow turn, U-turn, junction turn is slow enough to merit direct steering. It's frankly annoying as everything else regarding bike steering is beautifully intuitive and smooth when you have understood counter-steering. Am I the only fool who finds low speed steering annoying after hours happily counter-steering?

You might be the only one.

I generally try to avoid countersteering discussions because we all seem to understand it differently and I've already proven that I can't sway very many people to my point of view.

To me, steering at all speeds is consistent. But I've been on two wheels since I was about five years old. At low speeds, the front wheel still needs to out-track a bit to get the bike to lean, and I push the bar the same direction to get it to out-track at low speeds that I do for countersteering at higher speeds. The only difference that I, personally, see is that at higher speeds the bar pushes back and at low speeds it doesn't.

My opinion, and obviously not the opinion of very many other riders.
Go to Top of Page
  Previous Topic Discussion Topic Next Topic  
Jump To:
All Things (Safety Oriented) Motorcycle © Master Strategy Group Go To Top Of Page
  This page was generated in 0.59 seconds. Powered By: Snitz Forums 2000 Version 3.4.05