Take this out to the extreme and look at the traction on the tires from gravity occurring to a bike when on the vertical walls of a board track racer.
Counter Steering Question
- Thread starter STmark1300
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OP
OP
STmark1300
Ron
It certainly seems to me that the best place for the bike is in the closest to upright position because it will give the rider the best tire traction. However that is not a possible strategy when it requires the rider to hang to far off the bike, at least not for street riders. So then, we take the turns, throwing our weight down with the counter steering. That allows the bike to be in the best traction position possible and not riding on side of the tires. Ideally the weight centers on the pegs. That's what I am getting from this conversation.
ReSTored
Site Supporter
+1
Aside from actually turning the handlebars at slow parking lot speeds 100% of motorcycle turning is done, consciously or subconsciously, by counter steering. Putting weight on a footpeg or hanging off will not cause your bike to turn unless you are counter steering. Leaning into a turn or hanging off changes the bike's center of gravity and reduces relative bike lean angle vs. not. Watch a GP race to see extreme hanging off and how it can maximize cornering speeds and reduce lap times. On the street on an ST type bike leaning your upper body into a turn or hanging off slightly has a very positive effect on cornering capability. You can corner faster or maintain speed and reduce your lean angle if you are more comfortable with this approach.
Bingo! And if you want some technical data I did some extensive research on this 10 years ago. See http://koczarski.com/Motorcycles/MotoGeometry/Info.htm.
You can do two things to carry more speed through a turn.
1. Lowering the riders weight would allow you to either decrease the lean angle for a given speed and turn radius, increase the speed for a constant lean angle and turn radius, or tighten the corner for a given speed and lean angle.
2. Shifting you weight to the inside of the turn also gives you the same options. You will increase you peg clearance if you
remain at the same speed and turn radius. You can either increase your speed or tighten the turn if you keep the same lean
angle.
If you simplify things and make the assumption that the height of the mass of the bike + the riders is constant there is one lean angle for any given turn radius and speed. If you sit straight up on the bike you and the bike will be at that lean angle. If you push the bike down but sit up like the guy in the picture below, an imaginary line through the composite center of mass of the bike and the rider is still the same for the given turn radius and speed.
As other have said, you can ride through the turn sitting straight up, tip the bike down and counter lean or hang off the bike and have the bike more upright.
If you are too hot for a given turn you have several options. You can slow down. You can take the turn wider and hope you don't run off the road You can lean more to the inside sitting straight up relative to the bike and hope you don't run out of clearance. Or if you're hanging off the bike with it tip more to vertical, counter steer a bit more and pull the bike down towards you and tighten your turn radius. My opinion is you are in a far better position just pulling the bike down to you.
The original posters question had to do with not being prepared and caught off guard when the turn comes up. If you're not already hanging and shifting your body it's going to be hard to adjust that situation much once you're into the turn. You can drop the inside elbow and shift your body pretty easily and give yourself a little more margin compared with just leaning the whole system, you plus the bike, in a straight up orientation.
Watch a MotoGP rider approaching a turn. They shift their butt and start hanging before the turn, then they counter steer, fall into the turn and adjust the bikes angle as their knee slides across the tarmac. They are basically in a fixed position and they adjust the angle of the bike for the path they want to take.
We're not on a track or hanging and leaning anywhere near a MotoGP rider but the principle is the same.
The guy on the right is tipped about the same as the guy on the left but he's lowered his mass to the inside. The composite angle of him and his bike is leaned over more. He's either making a sharper turn or going fast than the guy on the left.
My 2 cents worth.....
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That's correct. I think if you were to stand a staff on a scale with a weight on top and hinged at the bottom (to hold it in place) you'd see the indicated weight on the scale decrease as the staff fell to one side from vertical.
As the bike leans the weight on the tire patch would normally lessen. Since the bike is under acceleration the lateral g-force increases with relation to speed and degree of turning. At least that's what I think. I'm sure the proper instrumentation could prove or disprove this easily.
Yes Sir! anything over about 10 MPH everyone steers a single track vehicle (your motorcycle) the same way. Counter Steering. If you realize it or not.
I think we are on the same page, but to clarify... you have to counter steer to keep the bike going straight once the body weight shift happens, which would be opposite of the curve. Without this "opposite" counter steering the bike will start to turn from weight shift, either upper body or whole body.
The Total Control Book has it listed in steps for the whole body shift, as stated already, you shift your weight before the turn which would also require you to continue going straight for a bit (opposite counter steering), changing pressure from the outside handlebar to the inside handlebar as the turn starts.
To add to the Total Control book (Lee Parks) reference which mainly discusses whole body shift, Sport Riding Techniques by Nick Ienatsch teaches upper body shift more geared to street riding.
Yes! I was getting confused. It seemed like counter steering was being considered as being optional or only effective at speed.
Same here. Lots of experience screwing around on bicycles as a kid.
It's sometimes hard to describe the process to people as it's just a natural thing.....
As to counter steering. Whether you think about it or not, you do it to start tipping the bike into a turn. Shifting your body weight to the left does not initiate a left turn, it's you pulling on the right grip that does that. It <might> feel like shifting your weight is doing it, but it's not. Next time you're riding in a straight line try gently tugging on the bars and see what happens. Or let go of the bars and try and steer the bike by shifting your weight.
OP
OP
STmark1300
Ron
I NEVER doubted that I was counter steering. My concern was in emergency situations I ended on the high side. Thanks for the help.
OP
OP
STmark1300
Ron
https://youtu.be/rlMbFlPzS24 Though this is not the same thing this is what I am afraid of, though it seems he is accelerating in the turn. Also I see that he is looking off to his left.
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ST1100Y
Site Supporter
Exactly, decreased contact patch of the rear tire due leaning angle, a tad too much engine power, plus some irregularity on the road surface... it could either be that the tire lost traction, could also be that touching the ground with pegs/frame simply lifts the rear off the ground...
Only functioning countermeasure would be depressing the clutch, let the bike coast through (and hope that tire and suspension cope with the situation...)
Any startled reaction, like snapping the throttle shut, applying brakes or jerking on the handlebar, make things only worse... he did steer into the slide, but leaning angle and direction were already beyond...
ReSTored
Site Supporter
I'd say excessive throttle, realization rear wheel is sliding out, panic, snapping the throttle off would be my guess.
This section of Mulholland Drive is infamous for crashes, people set up off the road on the inside of the curve with cameras and just wait for some unlucky soul to come by. Most run wide and off the road or the front end washes out or the rear slides out and then a lowside. A highsiding is fairly rare.
Not sure I agree with this. The force of gravity is always perpendicular to the ground. Since the mass of the bike is constant the force exerted by gravity is constant regardless of the lean angle. The tire has a constant internal pressure, and that pressure times the contact area is what supports the bike. Therefore a vehicle always has the same area of contact * the internal tire pressure which is equal and opposite to the force of gravity if you do a free body diagram of the vehicle, (see pic below). As the bike leans around a turn you get horizontal component of force due to centrifugal/centripetal forces. The horizontal component of force is offset by the red force vector times the coefficient of friction between the tire and the ground. If you lean enough and go fast enough the blue force will get big enough to overcome the frictional forces and you slide.
These two components of force make up the green vector shown below. I've attached a 2nd free body diagram which shows the forces acting on the bike and the resultants at the contact point. The vertical weight is equal to the bike and the rider at all times, neglecting bumps in the road, etc.
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Push the inside grip, don't pull, at least that is what I learned from a Total Control class and an instructed track day. Using both arms to countersteer is less accurate and reduces feedback from the front contact patch. Pulling the outside grip works as well I guess, same one-arm technique, just pulling instead of pushing.
I know certainly of times that " oh fudge, push, push, push, push" the inside grip allowed me to instantly increase lean angle and speed up rate of turn and make a corner I thought I was not going to make because I was too fast, misjudged the radius at entry, or otherwise surprised due to my misjudgement. While countersteering a bike is somewhat intuitive and done without conscious thought it does take conscious thought to push HARD and push NOW and know what the bike is going to do. I think this is why MSF and others use it in teaching curriculum.
A very good drill is to find a long stretch of road with a dotted line separating travel lanes and no traffic like a commercial or industrial area on a weekend morning. Starting at about 35 mph set up a weave between painted dots and note the effects of just "riding the bike steering" then adding and honing finesse techniques of pressing legs against the tank and feet down on foot pegs. There are all sorts of practice opportunities in what is just a straight piece of road. Holding the same speed, say 45 mph, the flip, flip, flip of quick repetitive left & right transitions to clear dots is markedly different from drawing out the radius of turns into a series of longer radius esses at the same 45. Quick repetitive transitions use a lot of arm and upper body and the longer esses bring the hips and legs into it.
I know certainly of times that " oh fudge, push, push, push, push" the inside grip allowed me to instantly increase lean angle and speed up rate of turn and make a corner I thought I was not going to make because I was too fast, misjudged the radius at entry, or otherwise surprised due to my misjudgement. While countersteering a bike is somewhat intuitive and done without conscious thought it does take conscious thought to push HARD and push NOW and know what the bike is going to do. I think this is why MSF and others use it in teaching curriculum.
A very good drill is to find a long stretch of road with a dotted line separating travel lanes and no traffic like a commercial or industrial area on a weekend morning. Starting at about 35 mph set up a weave between painted dots and note the effects of just "riding the bike steering" then adding and honing finesse techniques of pressing legs against the tank and feet down on foot pegs. There are all sorts of practice opportunities in what is just a straight piece of road. Holding the same speed, say 45 mph, the flip, flip, flip of quick repetitive left & right transitions to clear dots is markedly different from drawing out the radius of turns into a series of longer radius esses at the same 45. Quick repetitive transitions use a lot of arm and upper body and the longer esses bring the hips and legs into it.
Centrifugal???? Can we please put that imaginary force to rest.
I took high school physics as well and while it may not be a force when applying the laws of motion it seems to be when on a carnival ride, and if in reality it is just your body wanting to continue in a straight line what difference does it make?
Gerhard
Ya, ya. Yin and yang.....
You mean you applied both front and rear brakes to scrub off a little speed.....linked braking system, remember?Ever since buying my first ST1300, I have found that they get me out of trouble a lot better than I get into it!
There have been a number of times that I find myself coming too hot into a curve, and every time the ST1300 delivers me out of it. Most of the time it just takes a little more lean by counter steering! A few times I have dragged the rear brake just a little to scrub off some speed, and then add the counter steering to it, it goes through just fine, my heart is pumping a little faster, but the bike did it's job!
I love this bike because of this.
I very seldom find that, other than scraping the front on my boot, I'm scraping pegs!
The mantra I learned way back was 'push right go right/push left go left'. It instilled one arm steering and was easier to remember than 'pull right go left...'dduelin said:
Just to help clarify for some I had to add this to the common physics argument hi-jack here. (and for good measure to further hi-jack: a high side is usually a chopped throttle after effect when trying to save a low side-discuss).
In any case, I like this paragraph to better explain the meaning of centripetal versus centrifugal "forces".
Taken from http://www.physicsclassroom.com/class/circles/Lesson-1/The-Forbidden-F-Word
When the subject of circular motion is discussed, it is not uncommon to hear mention of the word centrifugal. Centrifugal, not to be confused with centripetal, means away from the center or outward. The use of or at least the familiarity with this word centrifugal, combined with the common sensation of an outward lean when experiencing circular motion, often creates or reinforces a common student misconception. The common misconception, believed by many physics students, is the notion that objects in circular motion are experiencing an outward force. "After all," a well-meaning student may think, "I can recall vividly the sensation of being thrown outward away from the center of the circle on that roller coaster ride. Therefore, circular motion must be characterized by an outward force." This misconception is often fervently adhered to despite the clear presentation by a textbook or teacher of an inward force requirement. As discussed previously in Lesson 1, the motion of an object in a circle requires that there be an inward net force - the centripetal force requirement. There is an inward-directed acceleration that demands an inward force. Without this inward force, an object would maintain a straight-line motion tangent to the perimeter of the circle. Without this inward or centripetal force, circular motion would be impossible.
Have a great Saturday.
In any case, I like this paragraph to better explain the meaning of centripetal versus centrifugal "forces".
Taken from http://www.physicsclassroom.com/class/circles/Lesson-1/The-Forbidden-F-Word
When the subject of circular motion is discussed, it is not uncommon to hear mention of the word centrifugal. Centrifugal, not to be confused with centripetal, means away from the center or outward. The use of or at least the familiarity with this word centrifugal, combined with the common sensation of an outward lean when experiencing circular motion, often creates or reinforces a common student misconception. The common misconception, believed by many physics students, is the notion that objects in circular motion are experiencing an outward force. "After all," a well-meaning student may think, "I can recall vividly the sensation of being thrown outward away from the center of the circle on that roller coaster ride. Therefore, circular motion must be characterized by an outward force." This misconception is often fervently adhered to despite the clear presentation by a textbook or teacher of an inward force requirement. As discussed previously in Lesson 1, the motion of an object in a circle requires that there be an inward net force - the centripetal force requirement. There is an inward-directed acceleration that demands an inward force. Without this inward force, an object would maintain a straight-line motion tangent to the perimeter of the circle. Without this inward or centripetal force, circular motion would be impossible.
Have a great Saturday.