Steering?

[Racing roadkill]

So is the answer to the OP's question: that at all speeds, at the initiation of the turn, your handlebars turn left to go right; and right to go left.

Physics: To turn you have to accelerate the combined mass of the bike and rider towards the inside of the turn.
Hypothesis:
At low speed you lean to the left to go left, that turns the front wheel right slightly before you steer left to go left. And at speed the counter-steer is obviously much quicker and almost part of the lean, and after the turn has been thus initiated and one's into the turn, one steers (ie has the handlebars turned so the front wheel points to the inside of the turn). If the bend tightens the response should be more lean (with the associated countersteer albeit 'instinctive') and resist the inclination to 'just' turn the handlebars a bit more.

Pretty much.

 

[Yellow Saddle]

But when you lean by force (for the pedant, you know I don't literally mean any force, but by brute force, ya know. Not using the nice eloquent controls of a bicycle). If you lean to the right, the front wheel deflects left as your leaning is applied behind the pivot of the steerer, this still counter steers.

The best way to prove this is to lock the handle bars. Or film the stem of the bike with a line painted on it while you ride no handed to watch the deflection.

http://socrates.berkeley.edu/~fajans/pub/pdffiles/SteerBikeAJP.PDF

That is an excellent description of the process, this applies not only to motorcycles, but to bicycles, and push a long scooters. It is applicable to all 2 wheel, tandem layout vehicles.

The reason I asked whether Dirk can ride no hands or not is to demonstrate that counter-steer is a non-issue for cyclists. We don't think about it, we don't consciously do it and we steer our bikes using body English, leaning, pushing down on the inside pedal, flicking the hip, dropping the head etc. The fact that there is a momentary counter force as the steering direction initiates is neither here nor there. In motorcycle "advance training" establishments they introduce it but I'm not sure it contributes anything and it certainly doesn't scale well to bicycles. We don't have to be taught to counter steer. We simply steer.
Children happily ride push scooters with tiny, lightweight wheels without thinking about countersteer. There is an approaching-zero gyro on those scooters. The concept of countersteer also invoke images of bikes steering constant diameter turns with some sort of opposite-lock position of the steering. This is not true. In such a turn the front wheel points in the direction of the bike's trajectory. It is the set-up of the turn where the gyro comes in and then disappears. But you know this.

 

[Cubist]

I actually used to road race motorcycles at International level. For fast direction changes you have to countersteer - leaning has little effect.
Bicycles are no different.
Whether you actually consciously realise you are doing this is an entirely different subject.

The best way to realise doing it is to ride a quad. After years of riding big hairy stinkwheels I had a go on a quad and soon realised just how much I was pushing the left hand bar to turn left.... quite a hard nudge and confused me no end until I got the hang of it all.

 

[Smokin Joe]

[QUOTE 4300959, member: 45"]I'd agree with that, except for the motorbike bit. Countersteering is essential, very noticeable, and taught in basic training not advanced.[/QUOTE]
I was never taught it, passed my IAM test before the phrase came into common usage and earned my living on a bike for a couple of years without even being aware of the phrase.

I didn't need to know what it meant, because every bike I road counter steered without any input from me. It's how a two wheeled vehicle reacts when you bank it over, you don't need any rider input at all. Instructors who "Teach" it are just repeating the latest buzz phrase, in reality they are trying to show you how to do what you have been doing ever since you first got on a motorcycle. If you didn't you would go straight on and crash every time you got to a bend. I liken it to trying to teach an adult that to walk forward one foot has to first go in front of the other one, and treating it like it is some sort of revelation.

 

[Smokin Joe]

[QUOTE 4301468, member: 45"]Nobody is treating it like a revelation. Being conscious that you can tighten into a turn by pushing on a bar is useful. Countersteering as described is not something a motorbike does naturally, it's a positive action of the rider.[/QUOTE]
I have a radio controlled model bike with free turning front forks. When it banks to one side the front wheel counter steers with no help from anywhere, it is just what a two wheeled vehicle does when it leans into a corner.

Only a glorified toy, but the principle is the same. Lean the real thing over with only a light grip on the bars and no pulling or pushing and it does exactly the same.

 

[PhilDawson8270]

I was never taught it, passed my IAM test before the phrase came into common usage and earned my living on a bike for a couple of years without even being aware of the phrase.

I didn't need to know what it meant, because every bike I road counter steered without any input from me. It's how a two wheeled vehicle reacts when you bank it over, you don't need any rider input at all. Instructors who "Teach" it are just repeating the latest buzz phrase, in reality they are trying to show you how to do what you have been doing ever since you first got on a motorcycle. If you didn't you would go straight on and crash every time you got to a bend. I liken it to trying to teach an adult that to walk forward one foot has to first go in front of the other one, and treating it like it is some sort of revelation.

I may be being picky but......

"very bike I road counter steered without any input from me" - Without conscious input, you certainly do give an input to counter steer.

"It's how a two wheeled vehicle reacts when you bank it over, you don't need any rider input at all." - This is backwards, the bike banks BECAUSE of counter steering, there is no other way to steer a bike.

People just aren't aware of it, as when we learn to ride bikes at 3 or 4 years old or whatever age, we learn to do this subconsciously. We are not aware of this action until it's pointed out, and then it's denied massively as it's counter-intuitive. But, it is the only way to steer a bike, our brains figure it out through experience.

In fact, if you watch a young child learning without stabilisers and go wobble violently before falling, you can see what happens before the brain has clicked that turning the bars left initially lean the bike right.

I posted a pdf above about the physics.

View: https://www.youtube.com/watch?v=C848R9xWrjc



View: https://www.youtube.com/watch?v=4PbmXxwKbmA



View: https://www.youtube.com/watch?v=MFzDaBzBlL0


People talk about it as an "option", but it is not, it really is the only way to steer a bike above walking speeds, the heavier the bike, the lower the speed in which the steering changes.

You're right, it's not a revelation, but the concept is difficult to grasp, and many do get the points backwards.

 

[PhilDawson8270]

[QUOTE 4301468, member: 45"]Nobody is treating it like a revelation. Being conscious that you can tighten into a turn by pushing on a bar is useful. Countersteering as described is not something a motorbike does naturally, it's a positive action of the rider.[/QUOTE]

It is something that people do naturally, there is NO OTHER WAY to steer a 2 wheel tandem layout vehicle. 5 year old kids do it on push bikes.

 

[PhilDawson8270]

[QUOTE 4301495, member: 45"]It's the banking that's the issue. Sometimes on a motorbike your weight won't lean it enough and you have to countersteering to get it to lean more and tighten the turn.[/QUOTE]

Even on a pushbike, the countersteering is what initiates the lean. No-handed turning works by having enough weight to pivot the front wheel the opposite direction. This method is obviously far less effective on something as heavy as a motorcycle. But it is the front wheel deflecting away from the desired path that initiates the lean.

 

[Yellow Saddle]

I posted a pdf above about the physics.

From the PDF you posted:

The point I'm trying to make is that we can live without it and there's no use introducing it in training other than perhaps advanced motorcycle speed training which I'm unfamiliar with. I have to take Mr Paul's point about it tightening the turn when leaning no longer doing it simply because I have no experience in that regard. I never rode my motorcycle (I believe) to a point where I had to positively counter steer to make it turn steeper.

I disagree with the author of this PDF on one point, that being where he says countersteering is the reason why you cannot escape from falling when riding next to a curb because there is no space to countersteer. I believe the reason you fall when riding next to a curb is because you cannot ride towards the curb to balance. The tiny, tiny little bit of space you need to "coutersteer" away from the curb will always be available.

Back to the second post in the thread, countersteer is not about countering the gyro effect of the wheel, it is about invoking it to set up the lean that makes the turn. By the time you are in the lean the front wheel is already pointing towards your trajectory and the gryo (front wheel) is again spinning in that plane with no gyro forces exerted on the axle anymore.

 

[PhilDawson8270]

From the PDF you posted:

The point I'm trying to make is that we can live without it and there's no use introducing it in training other than perhaps advanced motorcycle speed training which I'm unfamiliar with. I have to take Mr Paul's point about it tightening the turn when leaning no longer doing it simply because I have no experience in that regard. I never rode my motorcycle (I believe) to a point where I had to positively counter steer to make it turn steeper.

I disagree with the author of this PDF on one point, that being where he says countersteering is the reason why you cannot escape from falling when riding next to a curb because there is no space to countersteer. I believe the reason you fall when riding next to a curb is because you cannot ride towards the curb to balance. The tiny, tiny little bit of space you need to "coutersteer" away from the curb will always be available.

Back to the second post in the thread, countersteer is not about countering the gyro effect of the wheel, it is about invoking it to set up the lean that makes the turn. By the time you are in the lean the front wheel is already pointing towards your trajectory and the gryo (front wheel) is again spinning in that plane with no gyro forces exerted on the axle anymore.

I certainly agree we can live without it. There's no point introducing it, as it makes people very confused about something they do anyway!

On a race track, changing directions at high speed does require considerable effort.

There's no doubt that countersteering happens both on motorcycles, and push bikes. Regardless of the method it creates a pivot at the steerer. I do entirely agree that bringing it up in any form of "training" isn't necessary.

Though the space "away" from the kerb isn't there as if you turn the bars left (kerb on the left), the front of the wheel will hit the kerb, if right, then the rear of the wheel will hit it.

It's certainly interesting from an engineering/physics perspective. But totally unnecessary for rider training.

 

[PhilDawson8270]

[QUOTE 4301758, member: 45"]I disagree. When I learned I'd spent a year on a piddly scooter. They put me on a Bandit for my training. On the first day out on it I was having trouble taking 90 degree left-hander off main roads, and the bike was wandering towards the wrong side of the road. The instructor's advice if in that situation was to push down with my left hand. And it worked. Not complicated nor confusing. Useful and simple.[/QUOTE]

The exception that proves the rule. Look at the reaction on this thread in general about, "turning left to go right"

 

[PhilDawson8270]

[QUOTE 4301766, member: 45"]I'd be interested as well to know why it's easier to balance a big bike on higher revs at walking pace.[/QUOTE]

I have a feeling that's not necessarily easier to "balance", but the engine response is much more linear at higher revs on most bikes, and thus easier to control smoothly at slow speeds. But I am just hypothesising, my brain is currently tied up on other stuff atm, so I do retain the right to be talking bollocks with this

 

[Ajax Bay]

it is the front wheel deflecting away from the desired path that initiates the lean.

Surely it is the lean that initiates the front wheel deflecting away from the desired path; or are these activities concurrent? Is it the gyroscopic effect of the rider's lean (roll) on the front wheel causing it to yaw (

It's countering the gyro effect of the spinning wheel.

) which causes it to 'counter-steer' (the rider is not actually steering is he/she)?

So the rider wishes to turn right and leans right the front wheel turns (very) slightly left (what causes this - it's not the rider 'steering' is it) and then the front wheel turns right steered by the rider, to keep the force from the tyres (both tyres' contact points) offering a combination of normal (ie countering gravity) and centripetal (ie accelerating the bike and rider sideways, so that a turn is fulfilled) and therefore the rider (and bike) upright(ish). How does the rider slow or cease turning right? By turning the handlebars more right without realising it?

 

[PhilDawson8270]

Surely it is the lean that initiates the front wheel deflecting away from the desired path; or are these activities concurrent? Is it the gyroscopic effect of the rider's lean (roll) on the front wheel causing it to yaw ( ) which causes it to 'counter-steer' (the rider is not actually steering is he/she)?

So the rider wishes to turn right and leans right the front wheel turns (very) slightly left (what causes this - it's not the rider 'steering' is it) and then the front wheel turns right steered by the rider, to keep the force from the tyres (both tyres' contact points) offering a combination of normal (ie countering gravity) and centripetal (ie accelerating the bike and rider sideways, so that a turn is fulfilled) and therefore the rider (and bike) upright(ish). How does the rider slow or cease turning right? By turning the handlebars more right without realising it?

Imagine you're in a car, or anything with 4 wheels. If you drive along a road at 30mph, then turn left at that speed. The weight is forced to the outside of the turn, you lean right, and the car leans right also.

If you now imagine doing this on a bike, the weight still MUST be forced to the outside, so turning left the bike will fall over right. So what the RIDER actually DOES, is turn the bars right, this causes the bike to fall left, then turns the bars back into the turn to "catch it", and keeping the forces balanced then to make the turn. To stand the bike up, the bars are then turned further into the turn.

These movements are only small, but it is the only way to steer a bike. Ride at a decentish pace down the road, and CAREFULLY push the right bar forwards with a little pressure, and feel which way the bike turns. There's no other way to turn, everybody does it subconsciously, even children do it. The brain is a wonderful thing, proven by this, the ability to master a very complex skill without actually having to understand what is going on.

 

[Ajax Bay]

Link to 'Speed Wobble' thread.