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-   -   Pub Argument: Can you change the direction of bike without using the bars. (http://forums.pelicanparts.com/bmw-r1100s-r1200s-tech-forum/425356-pub-argument-can-you-change-direction-bike-without-using-bars.html)

adrianw 08-15-2008 10:21 AM

Pub Argument: Can you change the direction of bike without using the bars.
 
Hi,

During a recent drunken discussion with a good friend he suggested that it was not possible to make a useful change in direction of a M/C without resort to the bars.

He used physics to suggest that changing the vector of a 200 Kg M/C doing 100 mph without resort to the bars was not a viable proposition, as the energy input was above the level that my own weight could affect.

However my own experience makes me think that a lot of steering input comes from my own weight positioning on the bike, without resort to pressure on the bars.

Anyone have any thoughts on this?

Can you steer a bike with a fixed front wheel by shifting weight alone?

I reckoned something on the reduced radius of the tire contact patch when you shifted your weight, but then I was drunk.

Tests on my way home suggested I might be right, but I'm not brave enough to try it with no hands.

Anyone got an evidenced based argument either way?

Thanks,

Adrian

ibppjr 08-15-2008 10:40 AM

No.

See California Superbike School's No BS bike.

adrianw 08-15-2008 10:48 AM

Ah yes he mentioned that.

How come?

Adrian

adrianw 08-15-2008 10:52 AM

Hi,

Does telelever make a difference?

No springs in the forks no Resistance etc?

I'm not arguing, I just want to understand.

Thanks

Adrian

hjr1100s 08-15-2008 11:28 AM

Yes.

Use your hips. Never tried this in a bar though... but I did on the road.

HJ

Chris Canning 08-15-2008 11:43 AM

I know of at least one well known rider who's ridden in the British Superbike Championship,who'd wear a pair of boots out with holes in soles of his boots because of the amount pressure he put on the pegs,getting the bike to steer how he wanted too.

ergomoto 08-15-2008 12:00 PM

+1 On the K Code "No BS Bike", I've tryed it...
 
It was my impression that this subject was long closed -on the road if not the bar. You need to initiate any turn on any motorcycle with counter steering (from the bars), in conjunction with appropriate body position to then maintain what ever intended course adjustment. See Keith Code's now notorious Super Bike School training bike with secondary fixed handle bars and students attempting to affect the direction of this bike with anything but steering. Hysterical -and the last word on the subject. :D

http://www.superbikeschool.com

BMW's innovative Telelever moto suspension is no different in regard to initiating steering -just more forgiving, all be it at an over all weight cost. Telelever steering may not be as visceral in regards to feedback experienced with conventional fork systems, but it is benevolent and can inversely considerably isolate spastic breaking and even heavy handed vise paws from the suspension equation as well. My '04 R11S has been happly doin' it for me for 4 years now!:p

Oh man, just got a K Code eMail update on "Levels of Throttle Control" -Code Scares me sometimes.:eek:

roger albert 08-15-2008 12:03 PM

Your friend is right. I didn't think it was even worth intelligent debate any more. It's a case closed scenario. Sure, weight plays a role, but it's relatively minor. I can, on a fairly straight road, ride miles at a time without touching the bars, but it requires a LOT of body english. A significant magnitude or quickness of direction change requires bar input, period. Both the physics and all objective tests back that up.

Worn boots mean squat. I wear out the bottom of boots moving myself around on a 150# race machine (that requires relatively little input) It has nothing to do with how much I am or aren't weighting pegs (which I only moderately do in any event) It's the result of me moving my own 150# back and forth continually.

Code has a bike that demos it quite well.

Now, there are some fast guys that feel otherwise, but their being fast, and understanding how and why they're fast (assuming any understanding exists) are two separate things.

1100s nut 08-15-2008 12:48 PM

I have another good bar question that alot of average riders will get wrong. If you are making a right turn....do you push the bar to the right or do you push it to the left? When you say push to the left you will get some strange looks. It does seem strange that is that way though.

Lane

ergomoto 08-15-2008 01:17 PM

Counter Steering
 
Counter Steering is often confused with drinking at one and talking about riding.:p

Chris Canning 08-16-2008 03:18 AM

Quote:

Originally Posted by roger albert (Post 4122350)
Your friend is right. I didn't think it was even worth intelligent debate any more. It's a case closed scenario. Sure, weight plays a role, but it's relatively minor. I can, on a fairly straight road, ride miles at a time without touching the bars, but it requires a LOT of body english. A significant magnitude or quickness of direction change requires bar input, period. Both the physics and all objective tests back that up.

Worn boots mean squat. I wear out the bottom of boots moving myself around on a 150# race machine (that requires relatively little input) It has nothing to do with how much I am or aren't weighting pegs (which I only moderately do in any event) It's the result of me moving my own 150# back and forth continually.

Code has a bike that demos it quite well.

Now, there are some fast guys that feel otherwise, but their being fast, and understanding how and why they're fast (assuming any understanding exists) are two separate things.

I should have said per race!!!

JimMoore 08-16-2008 03:43 AM

Quote:

Originally Posted by roger albert (Post 4122350)
Now, there are some fast guys that feel otherwise, but their being fast, and understanding how and why they're fast (assuming any understanding exists) are two separate things.

I think all the racers do pretty much the same things, but people tend to remember and emphasize the one or two things that really clicked for them.

It's like flying airplanes. You hear something ten times, and it makes no sense. Someone else says the same thing using slightly different words, and the whole idea clicks into place.

bikerfish1100 08-16-2008 03:53 AM

Quote:

Originally Posted by Chris Canning (Post 4123159)
I should have said per race!!!

maybe if your friend gets some panties that fit, he won't be squirming around on the bike quite so much.

invariably, the "countersteering" question comes up in the BRCs i teach, with students not "understanding" it. i just tell them it's magic, and that there is no point in trying to understand it. unlike Tinkerbell and clapping, you don't have to believe to make it happen!
so then they go out and do what i tell them to. they do, it works remarkably well, but some still don't believe me, even after doing it!

go ahead, try it yourself. try to steer your bike down a twisty road without touching the bars. yeah, you'll make it move, but not nearly enough to stay between the painted lines, unless you're going thru more gyrations than a dancing hippo in Fantasia. it's about efficiency of effort. oh yeah, don't send me the repair bill.

Peter Parts 08-16-2008 04:16 AM

Obviously a trick question.

Anybody with a throttle counter-force spring or, even better, a ThrottleMeister, can tell you you can steer just fine while waving with two hands at oncoming Vespa scooters. With the condition that on a BMW boxer, you need to either be above maybe 45 mph or have 22 lbs extra weight on the left side (or be good at sitting way off to the left).

But the question asked about not "using" the bars. While you can steer just fine (within broad limits), I suspect your bars are swiveling like they ought'a. So you ARE using them. Now, when I am waving with two hands, I am not able to pay any kind of close attention to the bars, so just guessing they are moving a minuscule amount.

BTW, one of the cardinal rules of bike posture (violated by Harley riders) is the need to be sitting so you can put pressure down on your feet. In turn, that doesn't compute well without tank knee pads... like on /2s and Brit bikes in days of yore.

DeltaNu1142 08-16-2008 05:05 AM

Quote:

Originally Posted by Peter Parts (Post 4123190)
Obviously a trick question.
Anybody with a throttle counter-force spring or, even better, a ThrottleMeister, can tell you you can steer just fine while waving with two hands at oncoming Vespa scooters. With the condition that on a BMW boxer, you need to either be above maybe 45 mph or have 22 lbs extra weight on the left side (or be good at sitting way off to the left).

Maybe I'm missing something... or oversimplifying, which is often the case.

I have a Throttlemeister, and a really pleasing last-3-miles-of-my-commute home which is a curvy, 35-mph road through a preserve with trees & fountains & the occasional deer or heron. Lately I've been in the habit of setting my throttle & just leaning through the last three miles hands-free, provided there's no traffic--and yes, a bias to the left is a requisite for staying on the road!

As speeds increase, as you'd imagine, responsiveness decreases, but I've gotten pretty comfortable with attaining respectable lean angles from left to right & back with no manual input to the bars. The bars do turn, but only as a result of the lean. (Leaning the bike shifts the position of the contact patch? How would one say that?) I don't have any practical experience on a bike with a fixed front wheel & I guess that's what I'm missing.

signit98 08-16-2008 06:05 AM

Quote:

Originally Posted by 1100s nut (Post 4122441)
I have another good bar question that alot of average riders will get wrong. If you are making a right turn....do you push the bar to the right or do you push it to the left? When you say push to the left you will get some strange looks. It does seem strange that is that way though.

Lane

...depends on the speed you are moving at... at slow speeds the bike follows direct steering input, wen you are going fast enough for the gyroscopic forces to take controll, it turns into counter steering...

This is one of those "We both are right" questions...

Peter Parts 08-16-2008 06:09 AM

Quote:

Originally Posted by DeltaNu1142 (Post 4123227)
Maybe I'm missing something... or oversimplifying, which is often the case.

I have a Throttlemeister, and a really pleasing last-3-miles-of-my-commute home which is a curvy, 35-mph road through a preserve with trees & fountains & the occasional deer or heron. Lately I've been in the habit of setting my throttle & just leaning through the last three miles hands-free, provided there's no traffic--and yes, a bias to the left is a requisite for staying on the road!

As speeds increase, as you'd imagine, responsiveness decreases, but I've gotten pretty comfortable with attaining respectable lean angles from left to right & back with no manual input to the bars. The bars do turn, but only as a result of the lean. (Leaning the bike shifts the position of the contact patch? How would one say that?) I don't have any practical experience on a bike with a fixed front wheel & I guess that's what I'm missing.

Right. We agree completely. I sometimes try to see how far I can ride hands free on the R1100S, like we used to do with /2s that were balanced. Sometimes a mile is possible on a dul road, but then I am old and unbalanced.

My sense is that the trick bike has an extra fixed handlebar that you hold for training purposes but that the wheel has to pivot normally. Anybody know?

ckcarr 08-16-2008 06:25 AM

The key is the word "Meaningful."

I suggest opening up your copy (which I know all of you have) of Nick Ieanatsch's "Sport Riding Techniques" to page 35 and studying what is discussed in this chapter.

Yes, you can make casual corrections using only body english and/or your legs grasping the tank tightly while loping down a sweeping country road. But you cannot make useful, aggressive or defensive, rapid cornering adjustments or turns without the handlebars. Period.

Fenring 08-16-2008 06:48 AM

Your friend is correct. While handles steering is possible at low speeds (as proved by stunt riders), at higher speeds it becomes very difficult and at some point impossible, limited by your own weight.

The common misconception arises from the fact that many riders countersteer without being aware of it, while at the same time shifting weight to make a turn. This can lead to a preconception that steering with hands is much less effective than it really is, especially because of the fact that bike steering is counterintuitively flipped resulting in "counter"-steering.

KMoore 08-16-2008 08:18 AM

Well its after 2am here and after reading this, I can't sleep, wondering why I turn the bars when cornering whilst wheel-standing a trials bike.... :confused:


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