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Counter Steering


senfo
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I'm sure that most of us here are aware of countersteering and that it's the only reliable and controlled way to turn a motorcycle at speed. What I am personally not sure of is what the front wheel of a motorcycle [at speed] is doing after countersteering and the bike is in a lean. We all know the concept. Push right, go right. Push left, go left. But does the wheel eventually turn back into the direction of the turn? In other words, pushing right will --obviously-- cause the wheel to turn left. Once into the turn, however, does the wheel turn back to the right?

 

At slower speeds while weaving in and out of cones, I know for certain that if I push right, the wheel will eventually turn right once the bike has started to lean (don't believe me, take a cruiser through some cones at slower speeds). What I am not certain of is what is happening at higher speeds. Is my observation simply based on the fact that while weaving through the cones, I'm not going fast enough for countersteering to be necessary?

 

Thank you in advance...

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At any speed you only counter steer to initiate or change the rate of turn. I.E. so many degrees/sec of compass heading. After the lean angle is set (synonimous with the rate of turn) then the handle bars are streight again. In other words, in a constant turn the handle bars will be streight. The bars are only moved again to change the rate/lean angle.

 

First post here. Really enjoy the forum.

 

Dan

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The initial counter steer "rips" the wheels out from under you as you know.

 

When you stop adding lean angle (pushing on the inside bar), the steering head will return to equalibrium. Equalibrium will dictate that the steering head be pointed to the inside of the turn. Not straight.

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OK, anybody have a fork? :rolleyes: Time for crow pie. Being a hard headed individual, I decided to try what everyone should do and experiment to see for myself who was right. I rigged a pointer mounted to the tripple tree that pointed to a scale made of styrofoam wedged between the windscreen and speedo. Marked where center was and went riding. I only had time to do one sweeping turn and a couple of times around the cloverleaf of a hiway entrance/exit. I did not have the room or inclination to do hang off fast around the corners. I stopped doing that stuff on the street as I got old...er. I save that for the track. Sure enouph you were right. The tip of my pointer was about 1/8 in. wide and around the cloverleaf the pointer was inside by one needle width. I never would have noticed had I not seen it with a scale.

One thing I DO know is that it's not this way with an airplane. Once you roll in the bank the ailerons are returned to neutral untill you decide to change the rate of turn again. I guess the difference is that on a cycle the inside of the front tire is against the pavement? Otherwise the forces acting on anything in a banking turn are the same. (accept when you hit gravel......)

 

So, I'm usually the first to admit when I'm wrong, and this is one of those times.

 

P.S. I've been riding ever since age 8 and I'm 45 now... so it's not like I'm new to this. Just learn something new every day.

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Aircrftr, my uncle is a pilot so I've been fortunate enough to have gotten some air time in and what you said is true of an airplane.

 

Also, thank you for the information. I was actually just going to see if I could come up with some way to test this for myself. And I have to give you credit for your idea. That was actually pretty cool :D.

 

Thank you much for the information.

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  • 3 weeks later...

Hey M1, can I call you M1?

 

What is equilibrium as it relates to front wheel/steering head and why is it toward the inside of the turn? My intuitive gut feeling is that it has something to do with the width of the front tire being smaller than the rear and perhaps the offset of the steering head angle ie. rake/trail...but you seem to know...

 

Cheers.

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  • 4 weeks later...

Hey all....First post here....Great forum.

 

OK, I read this thread a couple times and need a little clarity. I know and understand the concept of countersteering. Once at the desided lean angle I relax and let my handlebars pretty much do what they need to do on their own unless I need to make an andjustment in the turn.

 

I do notice that quite often the handlebars tend to want to turn towards the inside of the turn rather then stay straight. If I am reading everyone's post here this is normal, right? When I am hanging off the bike I notice this sensation of the handlebars turning towards the inside of the turn as being more magnified. Do I fight this and try to keep the bars straight and on the verge of countersteering or do I let the bars do their own thing.

 

I highsided a little over a month ago and unfortunately I have no idea how it happend as I was not going very fast and the next thing I knew I was up in the air. Now I have all these demons in my head and second guessing everything.

 

Thanx,

 

Buggy

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As already stated, you countersteer to basically throw your balance off on purpose. This sets your lean angle. Next, whether you realize your doing it or not, you turn the front wheel INTO the turn. You turning the wheel into the turn is what actually makes the bike turn. If you did not do this you would keep leaning the bike until it fell over. Turning the wheel into the turn serves 2 functions. First, it enables you to hold the bike at whichever lean angle you desire by turning sharper(righting yourself) or by turning less(more lean). Second, a byproduct of holding your lean angle is change of direction.

 

If you want to see it for yourself, walk alongside your bike with the front wheel straight, then lean the bike over. It will continue to go straight even though it is leaning. Next, go to a parking lot or somewhere else safe and do some slow controlled circles(riding the bike). The slower your speed, the more the wheel will be turned and the least amount of lean you will have. This is because there are hardly any g-forces to through you off balance into a high side. The faster you try to go around that circle, the less you will have to turn bars to the inside, but you will have to lean more. This is because the g-forces are higher to make you highside so you need to lean farther inside. The reason you dont have to turn the bars to far off center at speed is because you have a greater lean angle at higher speeds than when you went around that slow circle. When your bike leans and you turn the bars, the clock position of the tire where it contacts the ground changes. Example: Think of your front wheel as a clock looking at it from the left side. Top is 12, front is 9, rear is 3, and where it contacts the ground is 6. When in a lean going around a corner the point at which the tire contacts the ground has moved to about 7 o clock. Now, since a tire is round, and its contact patch is more forward as your leaning, your bike wants to follow the curve of the tire. Im sorry I know this is hard to understand from reading this. Its better demonstrated. To see for your self, stand your bike straight up. Mark the tire where it touches the ground. Then have someone lean the bike over as far as safely possibble with the bars slight turned inside. Now mark again where the tire touches the ground. You will notice it is farther forward even though the bike has not rolled(becasue your buddy was holding the brake the whole time). Now if you take a good look at the contact patch on your hands and knees at this new spot with the bike still leaning and bars turned, you will see that part of the tire is actually facing farther into the turn than the 6 oclock position due to the roundness of the tire.

 

 

To answer the last post, the reason your bars want to turn inside is due to the caster angle of your forks(alignment). The closer this angle is to 0 (forks straight up and down), the harder the bars will want to turn inside. The greater the angle(like a chopper), the more the bars will want to stay straight. Higher caster angles are good for high speed stability, but hurt turning(why choppers cant turn). Lower angles turn better, but sacrifice high speed stability. This is why racers adjust how far the forks come through the trippleclamp for different tracks, it adjusts the casterangle. You should not let your bike due whatever it wants. YOU are the one in control of it. Most sportbikes will drive themselves around a corner after you set the lean due to their alignment setup and the gyro affect of the wheels spinning which i wont get into right now unless asked. If you have a bike that is more for cruising than the track, the bars will want to turn more than they should. My roomate has a Buell Lightning and his does this. When I ride it around a corner, I have to actually keep pressure on the inside bar all the way through the turn to keep the bars from cutting to the inside and highsiding(this might be what happened to you). When I ride my gixxer, I can go around a corner without any hands whatsoever. All I do is lean and the bike drives itself through the corner. Just boils down to alignment.

 

Bottom line, all bikes are different. You know how far you should be turning the bars to stay at a certain lean angle. If the bike wants to go past it, dont let it. What I did to practice countersteering was finding a barron road with passing lane stripes painted in the middle, and weave in and out of each one. In notime you will notice you can go faster and faster and not touch the lines. I am at a point where I can go about 60 and not touch the stripes. Of course my bike probably looks like a paint shaker from behind flicking back and forth so fast. For safety's sake do this with no cars around. Desert road or dead end. Once you get comfortable doing this you shouldn't even have to think about countersteering when going around a corner. It might be better that you dont anyway. I know it messes me up. Make it a natural thing, then when you going around a corner, do whats natural and your wont even have to think about it.

 

Sorry so long guys.

Happy riding!

Ken

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Ken, thanks for the reply. It was insighful and got me to thinking. As I read it I was vividly able to recall my accident and I distinctly remember the front end feeling light and the bars wanting to turn towards the inside of the turn. I remembered some front wheel chatter then a heavy bump from the seat into my right butt cheek. The next thing I recall is being over my instrument cluster looking down at the bike and the road and thinking that this is going to hurt.

 

My bike is a Honda 954RR so the fork alignment should not be as condusive to this sort of behavior. On Friday night I adjusted my suspension to those found on www.sportrider.com and found that the bike handles so much better then in stock form. With the new settings I was able to go into corners feeling much more solid and much less feedback from the bars (wanting to turn towards the inside of the turn) I also weighted the outside foot peg and countersteered as mentioned in the TOTW II book. This also made a huge difference.

 

This thread has helped a lot!

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Ken... I have a Buell Firebolt. I also need to keep a VERY minimal ammount of pressure on the inside bar to maintain lean angle... Unless I hang off properly. Also... The original D207's that come with the Buells (except for the "CityCross" model) cause this as well due to the fact that they are not a sharply profiled tire. The rear especially is very flat compared to most other sport bike tires. I switched to the Metzeler Sportec M1 and as long as I hang off a little, they work wonderfully. No tendency to stand at all unless I use the front brake mid-turn.

 

Anyway, I just wanted to mention that if your friend still uses the D207's, it's worth it to swap to Pilots, Sportecs or Diablos.

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You pilot guys: I spent a lot of years wringing out some good aerobatic airplanes and one thing I learned: in reality the airplanes ailerons are not exactly turned completely back to neutral nor are the rudders and obviously not the elevator. Adverse yaw causes the airplane to behave very similarly to a motorcycle. After the banking you return the alieron and rudders to ALMOST to neutral, but the outside wing is still taking a slightly faster path than the inside, especially above 30 degrees of bank. Get em up about 75 degrees of bank and some other interesting things start to happen as well, again similar to what a motorcycle could be expected to do from what I have read.

 

Try some "blind" hood work a with partial panel - block off your Turn Coordinator and Artificial Horizon and you will find out the truth about airplanes as well.

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  • 1 month later...

A clear definition of caster angle or rather rake and trail as it is referred to on a motorcycle...(as you can change caster angle on a car without altering ride height, more specifically the length of the fork, and hence trail) would be helpful in understanding exactly what is going on here and why. Or at least the next step in my mind. I'm too tired to get into it now, but, I'll give it a go tomorrow or next day.

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This is why we have inserts for steering head now.

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HI Ken and everyone else

 

I read this thread and saw a little thing missed. The trail effect is what is pointing the front wheel. It will point it into the turn to ballance the bike at the lean angle asked for by the rider. Yes some bikes will respond slightly different but caster effect will always point the front wheel and ballance the bike, in a lean or going straight no matter.

 

The rider must CS the bike into a lean but you don't need to "steer" it again to find the ballance once leaned. I will conceed to having to have bar pressure once turned on some bikes to maintain a line but not until you need to, the majority of the steering into the turn after CS is done by trail.

Also the biggest cause of needing to hold the bars is a low front tire.

 

CS is also required to get the bike back out of the turn, turning into the corner to get the bike to stand up again.

 

Any CS thread will get to body steering eventually so yes you can throw the bikes ballance off and effect a lean with your body. Done in time with CS is the mose effective way, the heavier the bike the less effective it is.

 

The walking demonstration is a great way to show that a single track vehicle will CS if a lean is enduced.

 

As for the tire width, a rode bicycle handle just like a motorcycle with the same size tires on the front and rear. When I was riding 250 ninjas we would put 130 rear tires on and 120 in front in place of the 110 in front because it would turn easier with the tires closer in size.

 

Will

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Thanks Willy.

 

Would it be accurate to say that 'trail' is the distance by which the front axle trails an imaginary line drawn thru the steering head toward the ground?

 

And that the difference in angle between that line and the forks is the angle of 'rake'?

 

And that, like the wheel of a shopping cart or a 'caster' on your bed frame turned 'backwards', the wheel tends to stabilize itself by flopping around to follow or trail the steering pivot.

 

And that a chopper's front wheel is unstable because the trail is negative? That the front axle actually 'leads' the caster angle creating a tendency for the front wheel to want to stabilize itself by flopping around to a trailing position? Like the wheel of a shopping cart turned around backwards?

 

I always liked the shopping cart analogy because we've all had a cart with a wheel that is turned around backwards and flops back and forth trying to stabilize itself.

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Oh, and a great big 'Howdy" to ya Willy Ballistic! Great pic..you haven't aged a day. :P

 

And congrats on your racing...you inspire me to believe I have more riding/racing to do, yet. ;)

 

Peace

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  • 3 weeks later...

Thanks Willy.

 

Would it be accurate to say that 'trail' is the distance by which the front axle trails an imaginary line drawn thru the steering head toward the ground?

 

And that the difference in angle between that line and the forks is the angle of 'rake'?

 

And that, like the wheel of a shopping cart or a 'caster' on your bed frame turned 'backwards', the wheel tends to stabilize itself by flopping around to follow or trail the steering pivot.

 

And that a chopper's front wheel is unstable because the trail is negative? That the front axle actually 'leads' the caster angle creating a tendency for the front wheel to want to stabilize itself by flopping around to a trailing position? Like the wheel of a shopping cart turned around backwards?

 

I always liked the shopping cart analogy because we've all had a cart with a wheel that is turned around backwards and flops back and forth trying to stabilize itself.

 

Hi Racer

The line drawn through the steering head hitting the ground and a verticle line from the axle hitting the ground is the trail (if the axle line hits behind the head line). You can have the forks at a different angle to the head but whatever the head angle is is the "RAKE". You can see some of the chopper guys using a head angle in the thirties and a fork angle in the fourties trying to get some trail back into them.

 

The shopping cart caster is a good demo but you must keep in mind that it has no rake, a verticle line drawn from the pivit to the ground and one from the axle to the ground would be the trail on a caster wheel.

 

Will

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