The Bum Steer

[Bass]

However, I'd have to see something more substantial than a vague claim, with no references, that someone has proven gyroscopic forces not to be a major factor in the mechanics of motorcycles before I'm willing to accept it.
Because, as you say, the theory is neat and tidy - not easily understood in a compound 3D environment - but still it is pretty much bullet proof.
..

That's entirely fair and is also the major failing of my side of the discussion so far.
However I'm on dial up in Oz this week and it's just too effing slow for me to do any serious research

[Ixion]

Or perhaps my post in another countersteering thread.

If I was an engineer I'd be heading off to London.

Well, that is VERY interesting.

A comprehensive study of the effects of acceleration and braking on motorcycle stability with the use of the advanced motorcycle model is presented. The results show that the wobble mode of a motorcycle is significantly destabilised when the machine is descending an incline, or braking on a level surface. Conversely, the damping of the wobble mode is substantially increased when the machine is ascending an incline at constant speed, or accelerating on a level surface. Except at very low speeds, inclines, acceleration and deceleration appear to have little effect on the damping or frequency of the weave mode. A theoretical study of the effects of regular road undulations on the dynamics of a cornering motorcycle with the use of the same model is also presented. Frequency response plots are used to study the propagation of road forcing signals to the motorcycle steering system. It is shown that at various critical cornering conditions, regular road undulations of a particular wavelength can cause severe steering oscillations. The results and theory presented here are believed to explain many of the stability related road accidents that have been reported in the popular literature.

So it's NOT just imagination that bikes handle better on uphill corners than downhill ones. 'it's scientific like.

[Ixion]

The thesis the site links to is even mor einteresting (even if does use bloody LISP - lotsa irritating silly parentheses ). 'Twill take me a few days to wade through it, but some of the conclusions are certainly interesting.

[Hitcher]

Does countersteering work the opposite way in the northern hemisphere?

[Ocean1]

Does countersteering work the opposite way in the northern hemisphere?

Well duh!, obvious innit, they ride on the other side of the road!

[Ixion]

Yes, but the beauty of it is that it is cancelled out by the fact that they also ride upside down (being on the arse end side of the world, n all)

[GSVR]

You'd have to use force sensitive pads on the handlebars. Your handlebars don't actually move when you countersteer at speed. It's all about the applied force...

http://www.kiwibiker.co.nz/forums/sh...2&postcount=77

Just picked up on the attachment on this post. Confirms what Ive been on about all along. Please read the whole paper.

[ital916]

here is the vid of the no bs bike keith codes made.

http://www.youtube.com/watch?v=3nRUeEkS644

[Mikkel]

So it's NOT just imagination that bikes handle better on uphill corners than downhill ones. 'it's scientific like.

Well, there is no substitute for emperical evidence is there?

Well duh!, obvious innit, they ride on the other side of the road!

And that leaves England, Japan, etc. where exactly?

here is the vid of the no bs bike keith codes made.

http://www.youtube.com/watch?v=3nRUeEkS644

Yes, that video proves quite readily that you CAN change direction on a bike without steering input to the handlebar (no active countersteer). It also very clearly shows that applying steering input at the handlebar increases the handling characteristics by "a whole lot".

Although I'd have to say he could hang a lot more off that bike when using the dummy bars.

http://www.kiwibiker.co.nz/forums/sh...2&postcount=77

Just picked up on the attachment on this post. Confirms what Ive been on about all along. Please read the whole paper.

Interesting article - I'll read it properly when I find some time later.
However, from what I just read it very much illustrates the complexity of the whole system and how utterly naive it is to say "this or that is not a (major) factor in [insert appropriate bikie term]".

[hayd3n]

Not true, there's another huge difference between a stationary and moving bike when it come to possible control inputs. YOU"RE MOVING, any change in steering input is effective because it's possible to change the contact patch.

also things like g force and momentum aswell etc

[Mystic13]

You'd have to use force sensitive pads on the handlebars. Your handlebars don't actually move when you countersteer at speed. It's all about the applied force...

So you're saying if we weld the bars in place, then get up to speed and push on the bar, the bike will turn. I think the bike wouldn't turn or would barely turn but only based on the moving of body weight.

Just me thoughts.