Cornering

[12DrinkMore]

http://www.superbikeschool.com/machinery/no-bs-machine.php

Dangerous Misconceptions

Now if you want to look a little further into this, what you will see is this; riders who still labor under the misconception that they body-steer are devoting themselves in a system that can do a great deal of actual harm. Firstly, it is seriously misguided to add an additional series of actions to the steering process. When it is quick, critical steering that is needed to avoid something, that lag I have observed so many times in street riders, could cost you your hide.

[dave_boo]

Something I still have to get through my thick skull.

I did way too much bicycle riding in mid/high school and the habits hard to break.....

[nikster]

Would love to try that solution bike... as I was recently wondering about this myself. In my test, I just tried to not move the handlebar and steer only with the body - it didn't work very well. Nevertheless, when doing tight and fast turns there's clearly something about staying on the inside "edge" that makes it work much better. Coming from skiiing and snowboarding, my only other experience with high speed steering.

So why does body shifting work on the bicycle and not on the bike? I guess it must be a combination of the (high) speed and weight of the bike/wheels (gyro effect).... probably mostly the gyro effect actually....

[LivinLOS]

But doesnt this totally disregard the change in the bikes lateral c of g, therefore leaving a lesser angle of lean, for the same amount of mass off center ??

Isnt that the reason for changes in body posture, not that the posture creates the turn, that it shifts the c of g point leaving a greater angle between bike and road, and better contact patch ?? Its this mass off center that the 'turned bar' is creating a force against to use that force as a balance, so the further a rider gets off the bike, there more mass there to use in balancing the turn..

Yes of course its counter steer that initiates a turn.. But body position moves the mass out there for the bike to balance as it rides through the turn ??

Am I miss understanding what they are complaining about.

[HTWoodson]

So why does body shifting work on the bicycle and not on the bike?

It's think it's just because a bicycle is so lightweight. Very small shifts in body positioning can turn a bike, which is why you can ride all over town on a bicycle without touching the handlebars at all, except to brake.

Something I still have to get through my thick skull.

I did way too much bicycle riding in mid/high school and the habits hard to break.....

Me too. My Honda Dream gives me some bad habits as well. I can body steer a bit on the small scooter, and I end up developing bad steering habits that are bad for riding on my big bike. On the Dream it is easy to throw the bike into a lean just by moving my hips left or right, very little steering input needed. Not so on my big bike.

[dave_boo]

But doesnt this totally disregard the change in the bikes lateral c of g, therefore leaving a lesser angle of lean, for the same amount of mass off center ??

Isnt that the reason for changes in body posture, not that the posture creates the turn, that it shifts the c of g point leaving a greater angle between bike and road, and better contact patch ?? Its this mass off center that the 'turned bar' is creating a force against to use that force as a balance, so the further a rider gets off the bike, there more mass there to use in balancing the turn..

Yes of course its counter steer that initiates a turn.. But body position moves the mass out there for the bike to balance as it rides through the turn ??

Am I miss understanding what they are complaining about.

You're correct, but I believe the author was attempting to dissuade people from relying solely on 'lean steering'.

[JonnyF]

Most people counter steer without realising it.

Going into a right turn they'll lean a a bit forward and a bit right. They think the shift in body weight has turned the bike when in fact putting weight on the right bar has pushed it down and caused the bars to turn to the left slighty.

I can remember when I was a teenager the first time I heard of it and I thought - I gotta try this - I tried it and it was immediately obvious that I'd been doing it all along just didn't realise it.

[12DrinkMore]

Most people counter steer without realising it.

I think that is very true. As indeed the "no BS bike" demonstrated. My first few days on a bike and I had zero idea about what was happening, trying to steer into the corner and many a dodgy wobble. Then suddenly it started to work, but I still didn't now why until some while later.

Hanging off the side is basically to keep the bike more upright and more rubber on the ground. And keeping low reduces the centre of gravity to make it easier to lean the bike, especially at high speeds.

Interestingly enough, after the initial counter-steer to lean the bike and you relax the counter-steer, the geometrics result in the front wheel steering into the corner, so the bike stays on track.

BTW this is how I also ride my Honda Dream. Works just as well with no weight shifting.

Several explanations on the web, two good ones are

http://en.wikipedia.org/wiki/Countersteering

http://www.motorcyclejazz.com/motorcycle_physics.htm

Edited August 16, 2009 by 12DrinkMore

[LivinLOS]

Also lets not forget, that even with thier no bs bike.. the forks are of course loose.. If the no bs bike had locked forks (near impossible to ride) then they are proving weight shifting isnt have any effect at all.. But I have to think that the weight shift creates slight fork turn, which is all part of it..

Pratting around with my brother on scooters we both were riding no handed on our motorbikes as you would on pushbikes, my brother is very balanced and a freestyle trick rider on pushbikes, he was able to lay back on the seat, and still steer the bike with just weight shifting through his butt, even low down and with his back on the sadlle.. That was more control than I have (also the fear of laying down as if it starts to go wrong you cant get back up fast enough) but without touching the bars we both rode downhill a KM or so negotiating multiple corners all totally without touching the bars. If weight shifting did nothing how would that be possible ??

The weight shift helps make the bar turn, of course actually just using the bars under control is faster and more accurate, but the way they describe it on the 'no bs bike' doesnt take that into account IMO.

[12DrinkMore]

The weight shift helps make the bar turn, of course actually just using the bars under control is faster and more accurate, but the way they describe it on the 'no bs bike' doesnt take that into account IMO.

The article did mention

Dirty Exceptions

Before I go any further I want to address off-road motorcycles. An off-road motorcycle will easily steer by pressing down on the inside peg, and in conjunction with shifting the upper body mass, will go over pretty easily . Still not what I would call good control but it can be done fairly efficiently.

Again, I am not a true tech guy but it occurs to me that the small contact patch on knobbies or dual sport tires and dirt bike steering geometry, which is not intended to provide an enormous amount of stability at speed, contribute to the reasons why steering results from weight shifts to the degree it does on a dirt bike.

But the gist of the article is that if you are attempting to steer a road bike by weight shifting you are not using the most efficient and safe method. There has to be an amount of counter-steering, even if subconscious, to start the turn. As the man said, almost one hundred riders had attempted to turn the bike purely by weight shifting. I have tried by moving my hands to the tank and trying to lean the bike over by shifting weight, standing on one peg, pushing one knee into the tank etc. The bike simply doesn't budge from the straight line, not one tiny bit.

[LivinLOS]

But the gist of the article is that if you are attempting to steer a road bike by weight shifting you are not using the most efficient and safe method. There has to be an amount of counter-steering, even if subconscious, to start the turn. As the man said, almost one hundred riders had attempted to turn the bike purely by weight shifting. I have tried by moving my hands to the tank and trying to lean the bike over by shifting weight, standing on one peg, pushing one knee into the tank etc. The bike simply doesn't budge from the straight line, not one tiny bit.

Do you have a steering damper ??

As I said.. I remember playing where we rode downhill about 1km, through 4 or 5 corners, one of which is nearly a hairpin, using only back brake and no hands on bars fuc_king about on honda wave style scooters.. Low speed so the front wheel gyro effect was of course low.. This wouldnt be possible if there was 'no' effect from weight change.

Think of this.. How do you steer when the front wheel is not on the ground.. weight only..

[LivinLOS]

I was trying to find a stunt vid where the rider was laid out on the bike and zig zagging really tight, turning in circles, etc all without hands on the bars.. Cant find which one of the 100's I must have watched on youtube it was.. Thought it was a king rommel vid but ??

But this is another clearly showing it.

If weight changes did nothing what he is doing wouldnt be possible..

I am not saying its the major force, of course shifting the bars, which creates side force as the bike line moves from under the weight, drops the bike far faster, and with more accuracy.. But you have to admit that saying it does nothing is also not correct, the vid there proves it.

[12DrinkMore]

I was trying to find a stunt vid where the rider was laid out on the bike and zig zagging really tight, turning in circles, etc all without hands on the bars.. Cant find which one of the 100's I must have watched on youtube it was.. Thought it was a king rommel vid but ??

But this is another clearly showing it.

If weight changes did nothing what he is doing wouldnt be possible..

I am not saying its the major force, of course shifting the bars, which creates side force as the bike line moves from under the weight, drops the bike far faster, and with more accuracy.. But you have to admit that saying it does nothing is also not correct, the vid there proves it.

Well, I've just been experimenting on my Honda Dream. This bike is easy to steer with just weight changes, in fact alarming easy. Although using counter-steering it flips from side to side much faster. The ability to move the bike with just weight must depend on several factors. I'll try on the kwacker tomorrow if I can find a stretch of concrete with no obstacles.

Wish I could give the "no BS bike" a try too.

[krading]

As part of our riding test in Oz we had to ride straight at the instructor and as we got close enough he would put out a hand indicating which way he wanted us to turn. The idea was to teach us to pull on the opposite bar to get the bike to turn.

Brave man.

edit spelling

Edited August 16, 2009 by krading

[Zzinged]

Don't forget that counter-steering only comes into the equation at speeds of like what... 50km/h and above? 40?

[rodcourt49]

Also lets not forget, that even with thier no bs bike.. the forks are of course loose.. If the no bs bike had locked forks (near impossible to ride) then they are proving weight shifting isnt have any effect at all.. But I have to think that the weight shift creates slight fork turn, which is all part of it..

Pratting around with my brother on scooters we both were riding no handed on our motorbikes as you would on pushbikes, my brother is very balanced and a freestyle trick rider on pushbikes, he was able to lay back on the seat, and still steer the bike with just weight shifting through his butt, even low down and with his back on the sadlle.. That was more control than I have (also the fear of laying down as if it starts to go wrong you cant get back up fast enough) but without touching the bars we both rode downhill a KM or so negotiating multiple corners all totally without touching the bars. If weight shifting did nothing how would that be possible ??

The weight shift helps make the bar turn, of course actually just using the bars under control is faster and more accurate, but the way they describe it on the 'no bs bike' doesnt take that into account IMO.

A little while ago I was in traffic and all of a sudden a lanky Thai guy lay back on his bike and interlocked both hands behind his neck, he then lifted his bare feet up onto the handle bars so as to steer and operate the throttle..he carried on like this weaving in and out of traffic for about a 100m until he returned to 'normal'..disappearing into the plethora of lot-tit-mak. Amazing stupid riding in Thailand.

[HTWoodson]

Good video LivinLOS.

Here's one of my favorites too:

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type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="660" height="525"></embed></object>" type="application/x-shockwave-flash" width="425" height="350"> Edited August 17, 2009 by HTWoodson

[LivinLOS]

Don't forget that counter-steering only comes into the equation at speeds of like what... 50km/h and above? 40?

Maybe we mean different things.. But counter steering should always work.

Your riding, your c of g is above and between the wheel (you hope ) your stable... You counter steer, the wheels go left, your weight stays there, so now you have weight on the right side of the wheels, you then steer into the curve, catch the weight (so you dont fall off to the right) balance the two forces of weight v centrifugal force, turn, and shift the weight back to above and between the wheels.

While it all operates slower at slower speeds, I dont see why the physics changes ??

What we are not including in this discussion in the gyroscopic effect of turning wheels, if you have ever sat in a pivoting office chair and held a spinning bike wheel by its spindle, this force can exert quite amazing pull.. So the faster your going straight ahead, the higher gyro effect there would be, keeping the bike (wheels really) straight and hindering weight movement. At least thats how I think it would work ??

[Fishenough]

As a bicycle racer from years ago, remember many a high level coach spending a day discussing steering, and counter steering, for quick turning and safety. Of course these lessons always felt like a complete waste of time to a bunch of youngens' that spend tremendous amounts of time riding all kinds of bikes; only wanting to be taught something to help us win races. Of course for any young and eager two wheeled rider, you can't win a race if you don't finish do to a steering mistake.

Coming back from morning coffee rode through the Mo abn with arms and legs (feet of the pegs) out. Beside making the D-Tracker feel pretty unstable, when I shifted to the right the handlebars could be seen (pretty darn sure but I was kinda wobbly) twitching to the left. Automatic countersteering? So I grabbed my mountain bike and tried it again, being more comfortable riding no hands on the bicycle at similar speeds. Got the same results: the bike appears to counter steer with no handlebar input.

To quote that link Wiki:

This is how countersteering works when riding no-hands. In order to turn left, a rider applies a momentary torque, either at the seat via the legs or in the torso that causes the bike itself to lean to the right, called counter lean by some authors.^[3] The combined center of mass of the bike and rider is only lowered, of course. However, if the front of the bike is free to swivel about its steering axis, the lean to the right will cause it to steer to the right by some combination of gyroscopic precession (as mentioned above), ground reaction forces, gravitational force on an off-axis center of mass, or simply the inertia of an off-axis center of mass, depending on the exact geometry and mass distribution of the particular bike, and the amount of torque and the speed at which it is applied.^[1][9]

This countersteering to the right causes the ground contact to move to the right of the center of mass, as the bike moves forward, thus generating a leftward lean. Finally the front end steers to the left and the bike enters the left turn. The amount of leftward steering necessary to balance the leftward lean appropriate for the forward speed and radius of the turn is controlled by the torque generated by the rider, again either at the seat or in the torso.

To straighten back out of the turn, the rider simply reverses the procedure for entering it: cause the bike to lean farther to the left; this causes it to steer farther to the left which moves the wheel contact patches farther to the left, eventually reducing the leftward lean and exiting the turn.

The reason this no-hands steering is less effective on heavy bikes, such as motorcycles, is that the rider weighs so much less than the bike that leaning the torso with respect to the bike does not cause the bike to lean far enough to generate anything but the shallowest turns. No-hands riders may be able to keep a heavy bike centered in a lane and negotiate shallow highway turns, but not much else.

Eloguent way of discribing a wobble........

Interesting article - gets ya thinking.

[12DrinkMore]

Well, I didn't feel terribly comfortable with the exercise, but chugging along at various speeds, took hands off the bar and lent over the side. The Kwacker will deviate from the straight straight line, but it's very slow "turn". Works better at slower speeds.No doubt with more practice and more extreme weight shifting it would be possible to do a long slow slalom, as that guy in the video demonstrated.

Although an interesting excercise, I think the conclusion is that knowingly using counter-steering provides far greater control and precision, and that in an emergency, the extra delay incurred by "bum shifting" could be fatal.

I also checked with the Dream and Kwacker at what speeds the counter-steering comes into play. At speeds above around 15 kms/hr I notice that I am still giving a very quick counter-steer to lean the bike and then turn into the corner. Above 30 kms/hr or so I just use counter-steering. Below around 15 kms/hr I am turning the bike into the corner.

[Zzinged]

In terms of motorcycling, countersteer is the process in which the rider turns the handlebars in the opposite direction he wishes to go. This is also used by car drivers when they're oversteering; they countersteer to prevent the car from spinning around completely. This is most evident in drifting.

If you're going too slow for the bike's momentum and the wheel's centrifugal force to affect you, you have to turn the handle bars in the direction you want to go to make the bike turn that way. This is how most people ride bicycles. Since they usually operate at low speeds, they have to turn the handlebars to change direction.

Leave shifting body weight out of the equation for a moment. As 12DM demonstrated, there's a certain cut-off speed at which turning the bike's handlebars in the direction you want to do results in you going the opposite way. Assuming all other factors are static (including the shifting of bodyweight in any direction) here's what happens at different speeds (I'm just pulling speeds out of a hat here because I don't know if it's the same for all motorcycles):

Walking the bike: you need to turn the handlebars in the direction you want to go.

10-15km/h: say you're doing a u-turn. you're still going slow enough for you to need to turn the handlebars in the direction you want to go.

60+km/h: you would certainly need to use countersteering to turn the bike now.

If you're going fast enough, the centrifugal force of the bike turning in one direction needs to be countered by leaning aginst that said force. Therefore, although the bike handlebar is turned to the left, the action of doing so results in the bike leaning over to the right which counters against the centrifugal force of the bike performing the right hand turn (which would make the bike lean to the left of upright if you were't already leaning right)

So basically, if you were traveling at speed and you turned the handlebars to make the bike go in the direction you wanted to go, the bike would fling you off on the opposite side. Instead you turn the handlebars in the opposite direction (only a little bit) to make the bike lean into the turn. At this point the bike is 'falling' but is kept from falling over completely by the tires and the bike's centrifugal force. To right the bike you simply turn the handle bars in the opposite direction of your turn and the same forces 'right' the bike.

Was that clear or did I cause more confusion?

Edit: Another example of how cornering forces affect you. If you're going fast enough and turn in one direction, your body leans in the opposite direction. Now imagine you're on a bike and in the same situation. You're gonna fall off the bike. The only way to avoid this is to lean into the turn. Now bring shifting of body weight back into the equation. Once the bike is already leant over and in the middle of a turn the rider's body position affects things such as rider stability and bike stability; those 2 being the most important reason to have correct body positioning while turning.

Edited August 17, 2009 by Zzinged

[12DrinkMore]

And while we're on the topic, here's a good tip for the pillion rider.

Every (non-biker) pillion rider I have had on the back tries to keep the bike upright by leaning out from the curve. With the average weight of Thai girls at 45 kgs (well, I prefer the smaller ones) I can generally compensate by not going so fast and more leaning. But this tip I read on the internet recently and it works and is very simple to explain!!!

Just tell her that if you're turning left she should look over your left shoulder and if you're turning right to look over your right shoulder.

[Kf6vci]

Try this at very low speeds: steer like with a bicycle - and you will find out that the bike behaves the opposite. Instead of turning left, it drops to the right.

Henceforth, rely on your subconscious mind to do the steering.

Is this what the OP is alluding to? If not, apologies.

Chris

[Sojourner]

It took me until I had graduated up to my Honda VTX 1800 before I realized body lean doesn't work. With my Africa Twin just shifting weight was all I usually needed, but did find myself in the wrong lane a few times. With my CB750 the need for more than body weight shifting was becoming more apparent but I was too ignorant to figure it out by myself. After viewing the video "Ride Like a Pro" I saw the light brother. Now riding the VTX (750+ pounds) is predictable and a lot more fun. Ride a heavy bike once and you'll see the difference between body lean and countersteering. In a parking lot use the bars in the conventional manner while riding the rear brake, slipping the clutch and modulating the throttle, but on the highway use countersteer and front brake with a little trailing rear brake. Safe ride everyone.

[elkangorito]

Steering in bicycles and motorcycles (very good explanation).

http://socrates.berkeley.edu/~fajans/pub/p...teerBikeAJP.PDF

Steering the motorcycle without turning the handlebars.

http://docs.google.com/gview?a=v&q=cac...hl=en&gl=au

Bicycle Wheel.

http://hyperphysics.phy-astr.gsu.edu/Hbase...bicycle.html#c3

[Zzinged]

lol Elkangorito, I think physics dissertations are a bit over the top for this thread Probably didn't help that I didn't understand most of the technical terms

[katabeachbum]

It took me until I had graduated up to my Honda VTX 1800 before I realized body lean doesn't work. With my Africa Twin just shifting weight was all I usually needed, but did find myself in the wrong lane a few times. With my CB750 the need for more than body weight shifting was becoming more apparent but I was too ignorant to figure it out by myself. After viewing the video "Ride Like a Pro" I saw the light brother. Now riding the VTX (750+ pounds) is predictable and a lot more fun. Ride a heavy bike once and you'll see the difference between body lean and countersteering. In a parking lot use the bars in the conventional manner while riding the rear brake, slipping the clutch and modulating the throttle, but on the highway use countersteer and front brake with a little trailing rear brake. Safe ride everyone.

Second that.

My (awfully heavy) VTX 1800 v-twin tought me whatever ridingposition I or my passanger had, it would not steer unless countersteering. A combination of weight of bike, weight of front suspension and wheel, and wheelbase i guess.

On a bicycle the slightest move of bodyweight is enough to steer, but actually countersteering without touching the bar I guess.

Countersteering doesnt mean you need to ride like a stiff, body weight can still be moved, espesially to reduce height of weight.