Steer In Opposite Direction Prior To Turn?

[racer]

ignore

[racer]

I really don't like this new set up on posting.

 

Very confusing.

 

I guess I should post that coment for admin.

 

The BB code is off and emoticons don't work either.

 

 

Edit: Ok if I go back to the board and click last post I can read the posts expanded in order of posting.

 

Edit: Now I can't do that either.

 

grrr

[racer]

QUOTE(harnois @ Jun 5 2007, 04:18 PM)

I just rode my bike to work this morning, so I did the test again and again and again and the result is always the same. I can remove my hands from the handlebars and still adjust the direction of the bike by leaning back and forth. Leaning off the bike in and of itself causes the bike to lean in that direction and turn in that direction.

 

 

 

 

Exactly.

 

LEANING back and forth.

 

That is motion and momentum.

 

Not purely position.

 

To isolate the handlebar pressure required to maintain a straight line while hung off, try your original test at 40 mph.

 

Establish a proper position, let go of the bars, and then observe the result.

 

If you let go of the bars first, the challenge is to see if you can hang off without turning.

 

Smoooooth. ;-)

[harnois]

Making smooth body position transitions is a whole 'nother subject. The subject I am interested in addressing is acknowledging that having the body in a static hang off position will cause the bike to lean and turn in that direction unless counteracted with a steering input. That is what the original post was about.

 

To isolate the handlebar pressure required to maintain a straight line while hung off, try your original test at 40 mph.

 

Establish a proper position, let go of the bars, and then observe the result.

 

Right. I did that. And the result is that the bike will gradually lean and turn in the direction you are hanging off. At 40mph it is very obvious. At 70 it is less obvious, but still definitely there.

 

I would suggest that performing that test at spirited riding speeds is necessary to make a final determination relevant to real riding conditons (unlike the pits, parking lot or the no BS video).

 

I tried it 70mph, and it is still obvious that the bike leans and turns in the direction if you are hung off the bike and does so solely from the static positioninig of the body off center of the bike. Public road riding and many race tracks will involve riding below 70mph.

 

If it happens at 70, it is possibly relevant. But generally I agree with you. It isn't that relevant, not something one really needs to put much thought into while riding. But it is relevant to the original post is all.

 

The bike is designed to be balanced left to right relative to the steering axis and wheels. Once your weight is positioned off center of that, it will lean. Hanging off properly has the same effect as if you were carrying a heavy saddlebag on one side of the bike. It will make the bike lean in that direction (gradually). If you were crusing down a highway with one saddlebag, you'd have to counteract that with a constant steering input, and if you were riding for hours it would get really annoying (don't ask ).

 

In most track riding situations you'll be braking when appraoching a turn. While braking hard, we'll be using the handlebars to hold our weight back to some degree (although I know it is best to try to do this as little as possible) and therefore we'll be pushing forward on both bars, and in this scenario hardly anyone is going to notice that they are pushing slightly more on one grip than the other. Therefore, it is not really relevant.

 

On the other hand, while crusing around the track during a no brakes drill, approaching turns off-throttle and in the hang off position, it is definitely very noticable that I have to push on the bars a bit to counteract the lean if I want keep it upright and going straight. While riding on public roads it could be relevant too since charging the turns and going hard on the brakes is not necessary conducive to keeping your license and staying out of jail. I don't even bother to hang off most of the time on public roads anyway but I know some poeple do.

[racer]

It doesn't seem to happen for me. I don't know what to say. Of course, I'm still on the gas when I move over which would tend to override any unbalancing force from being hung off. And I do stay a bit closer to the bike than you do judging by your photo. At 5' 6" and 130 lbs, all told, I probably present less of a lever for gravity to be sure.

[harnois]

It doesn't seem to happen for me. I don't know what to say. Of course, I'm still on the gas when I move over which would tend to override any unbalancing force from being hung off. And I do stay a bit closer to the bike than you do judging by your photo. At 5' 6" and 130 lbs, all told, I probably present less of a lever for gravity to be sure.

 

I only weight 20 pounds more than you and I also tried it hung off a lot less than normal. I think you have a very magical motorcycle.

 

Whoever "wins" this "argument" is still a retard, since you know what they say about winning arguments on the internet and the special olympics and so forth.

 

I doubt that the original poster or anyone else really care's about our ramblings but I have very much enjoyed our discussion.

 

The most interesting thing to come out of this was the discovery of this thread where Keith Code participates in a Body Steering vs. Counter Steering discussion:

http://www.r1-forum.com/forums/showthread.php?t=21254

I am utterly amazed by humans' ability to come up with the most bizarre explanations as to how they get their bikes to do what they do and why it does what it does. They can't even come to a consesus on something as simple as how to steer a bike. Subjects that are actually complicated, like say Global Warming, are doomed to eternal disagreement for sure.

 

On page 27 post number 24, post by Winders:

"Example that is easy to see: Hang off a bike that is going straight, the bike will turn the direction you are hanging off if you do not countersteer to keep the bike going straight."

 

Post number 529 by Keith:

"Ya, that is my expereince as well."

[racer]

harnois,

 

 

All due respect, I don't characterize the discussion as an argument. And I'm not actually trying to win anything.

 

My only thought is to the benefit of those who read this website in the hopes of learning something to help them ride with more control and confidence.

 

After twenty years benefiting from the wisdom and support of my sponsors, mentors, friends and competitors in the sport, many of whom are no longer with us while I have managed to survive, my only purpose is to help others by passing on what I have learned and sharing my experience in the hope that they stay with us a while longer.

 

To that end, trying different things, thinking it through and sharing the insights of others is, in my opinion, the point of this forum and the best way to sort things out.

 

So, at the risk of repeating myself, I do not dispute that it is possible to force a bike to change direction by shifting one's body. However, after further thought, I no longer think it is due to orthogonal torque at the front axle causing a precessional effect, but, rather, it is still counter-steering as the essential effect is re-directing momentum off-axis from the direction of travel.

 

At the end of the day, I think a picture speaks a thousand words and the No BS video pretty much speaks for itself. I think anyone can clearly see what is happening. And what isn't.

 

I hope everyone will continue to think about it and experiment. The more we learn the more there is to learn I always say.

 

 

Have you tried hanging off with full throttle at 40, 70...or 140 mph, yet?

 

(I use my thumb and forefinger on the throttle in lieu of a throttle lock to minimize any handlebar input.)

 

Let us know what happens.

 

 

For the record, if one wishes to build consensus, they will find a way.

 

I urge everyone to actually click the link in the preceeding post and read Keith's entire conversation in context.

 

 

Cheers,

racer

 

 

PS I've always thought of my motorcycle as magical!

[harnois]

All due respect, I don't characterize the discussion as an argument. And I'm not actually trying to win anything.

I agree. I was just mak'n jokes. Aparently, they weren't very good jokes.

 

My only thought is to the benefit of those who read this website in the hopes of learning something to help them ride with more control and confidence.

Completely agree. And to help ourselves.

 

Have you tried hanging off with full throttle at 40, 70...or 140 mph, yet?

At FULL throttle? No, haven't tried that. I don't see how it relates to the original post, since that is about approaching turns. But anyway it doesn't have to relate to the original post. I find hanging off at 140 is rather uncomfortable and unstable due to the wind hitting me. But I'll try it at 40 or 70. My hypothesis is that it will still gradually change lean angle toward the direction I'm hanging off but it will not change lean angle as quickly. Having the throttle on is going to slow down the process and going faster is going to slow down the process, and at some point it would get to be insignificant and very difficult to detect.

 

So, at the risk of repeating myself, I do not dispute that it is possible to force a bike to change direction by shifting one's body. However, after further thought, I no longer think it is due to orthogonal torque at the front axle causing a precessional effect, but, rather, it is still counter-steering as the essential effect is re-directing momentum off-axis from the direction of travel.

Holding oneself in a position off center with the bike will make the bike gradually change lean angle in that direction. If you want to discuss WHY it happens, here's how I see it:

 

Let's assume first of all that the rider makes his position change very smoothly and without affecting the bike as a result of his weight being tossed violently around on the bike. As you move off to the left side, the bike leans somewhat to the right, and your body goes to the left, and the combined bike-rider Center of Gravity doesn't change much (or maybe practically not at all). So you might at first think that nothing would change. But, since the bike is leaned to the right, the steering head tube is leaned to the right, thus due the trail of the front wheel (and possibly other less important things) the front tire will turn itself to the right of it's NEUTRAL POSITION* and continually hold itself to the right of the neutral point as long as you are hanging off. That then continually drives the tire out from under the bike towards the right, hense the bike gradually leans more and more towards the left. The bike is being rotated around its center of gravity by using traction with the ground as the levering force. It is no different than what happens when we countersteer, except that the handlebar turned due to the lean of the bike in that direction rather than due to our direct handlebar input.

 

*by NEUTRAL POSITION, I mean the steering angle of the front tire/forks that would make the bike maintain a steady lean angle. Which when going in a straight line is straight ahead, and when going around a turn it is slightly turned towards the inside of the turn. When the wieght of bike and rider are centered relative to the steering head, this will be the position that the tire and forks will keep itself in when there is no presure on the bars.

 

Going back to the original subject of hanging off while appraoching turns off throttle, when we counteract that gradual lean angle change with a slight push on the bar, what we are actually doing is just holding the bar straight, in it's neutral position* preventing the front wheel from being driven out from under the bike. But, it doesn't do any good to think about it this way when riding, because when riding except for parking lot speeds the handlebar is always so close to it's straight on position that we can not detect it's actual position or which way it is turned, we can only feel how much presure is required on the bar to get the bike to do what we want.

 

We can do certain experiments to demonstrate what the bike will do in certain circumstances. But to be sure WHY it does what it does would require much more elaborate experiments or testing that we are not likely to do with our bikes and our own time. That we leave to people like Keith Code and Tony Foale.

 

PS I've always thought of my motorcycle as magical!

We humans find leaning through turns be a fairly natural concept since we do it while running. So to me riding a motorcycle is like running except I can go a lot faster and don't have to work nearly as hard. It's like being a superhero with phenominal running abilities. Which, yeah, sometimes it does seem kinda magical.

[racer]

Hi harnois,

 

I approach most turns at full throttle.

 

I think that when the center of gravity moves left on a machine in motion that the axis of momentum will diverge from the direction of travel and countersteer the bike without needing to push the handlebar.

 

I don't think the bike leans to the right first.

 

I prefer not to leave anything to anyone else.

 

I find riding my motorcycle reminds me of flying my plane. Yaw, pitch and roll. But any object in motion in a 3D inertial frame of reference will exhibit those three basic degrees of freedom.

 

 

racer

[Cobie Fair]

Just got to this one too---you guys had a nice little discussion going on here

 

Here is another way to look at it, and experiment if you care to try it: if you hang off the bike in a straight line, lets say on the right-hand side, what happens to the lean angle of the bike? Stay the same, or do you have to counterlean the bike to the left to keep it going straight?

 

CF

[Keith Code]

Yes when we let go of the handlebars that means letting go of the throttle. The original post is about appraoching turns. So it is OK to be off throttle during our test.

 

The example of a bicycle is an extreme one because the bicycle is light. The motorcycle and it's wheels are much heavier yes, therefore, we can not effect is AS MUCH, but if it can be done on a bicycle, it can be done on a motorcycle, just to a lesser extent. And remember, I'm only arguing that there is a slight affect of hanging off, not a major effect.

 

The 500-pound weight is another extreme example, but if having that much weight that far off the side of the bike has such a major impact, then having less weight less far off the side of the bike will have a slight impact.

 

I just rode my bike to work this morning, so I did the test again and again and again and the result is always the same. I can remove my hands from the handlebars and still adjust the direction of the bike by leaning back and forth. Leaning off the bike in and of itself causes the bike to lean in that direction and turn in that direction. Just go out and do it yourself. At 40 mph the effect is not really all that subtle at all. I could be going straight down the road in the hang off position with my hands on the handlebars, then let go, and in seconds I'd be almost in the ditch. At 70mph is was much more subtle but still quite obvious.

 

If you are appraoching a turn off throttle, already in the hang off position, the bike will gradually change its lean towards the direction you are hanging off, unless you counteract that with a steering input on the handlebars. That is what the original post was saying and it is correct. If you have never noticed this before it's because you either do not hang off prior to turns, or you are subconsciously counteracting it. And since you are doing it subconsciously, you will of course argue that you aren't doing it at all.

 

The first time Keith told me in a classroom that I could turn my handlebars to the left and it would lean the bike to the right, I thought he was a nutcase, until I went out and tried it, and then it was obvious that he was right. Then he told me that I could release all presure on the handlebars in the middle of a turn and the bike would just maintain its lean angle. No, I said, for sure it will sit up and go straight. Then I tried it, and obviuosly he was right again. So we can debate this all day long or you can go out and ride your darn bikes and take your hands off the bars and lean back and forth and then you'll see.

 

I think it is very very important for people to understand countersteering and understand that it is like a 1000 times more effecting than "body steering." What we can do with our bodies alone I would hardly call "steering." But there is some effect.

 

Once you change the bike and rider combined center of mass the bike is necessarily out of balance and will tend to go in the direction of the imbalance which does require a very slight pressure to correct for when going straight and hanging off. It's barley noticeable but you do have to do it. Once you transition to braking there is still some pressure needed to maintain a straight line trajectory as you enter the corner. The bike should turn easier as you apply pressure to the bar to counter steer it. It's a small percentage but you could say it does help and it does. Is it body steering, well, we don't have to beat a dead horse on that subject, we all know we would never get through the esses or miss a car with only so called body steering so leave it at that.

 

The main point is that it is a very fine point and not critical to good control of the bike, it is just something that happens. Subtle imputs happen all the time on the bars. The great thing about the No BS bike is that you become aware of them immediately once you to the top bars.

 

Keith