How much lean angle have I got?

[Ocean1]

By hanging off your bike you move your COM off the centerline without leaning the bike. This allows you to corner faster at a lower lean angle.

Yes, explain what effect it has on lateral G given the same speed.

[Macstar]

one of the many wonders of motorcycling.
I too own a hornet.
I have reached the edge of my rear tyre plenty of times.
I ain't no slow poke.... but I'm no casey stoner either, there are much faster riders I ride with.
and the wonder bit .... I've had stuff touch down , maybe 3 times in 2 years

maybe I hang off more than your something

Yeah, my riding mates tell me I should hang off the bike more but I can't really be shagged. My developed style (good or bad), is shifting my weight to the pegs and maybe scootling my ass a little to the side that I am leaning, but I don't hang off the side of the bike, hence the peg scraping.

I read in "the Pace thread" that riding this way gives the appearance that you are going slower than you really are - cause you're not dragging a knee along the ground etc. and therefore good for calming/tricking other motorists and cops.

Good suspension set up will also of course avoid a lot of peg scraping action too - which you may have BTW!!

[xwhatsit]

Yes, explain what effect it has on lateral G given the same speed.

None, of course, but I think what people are trying to say is that with a shallow lean angle your bike has a higher limit for lateral G.

[Mikkel]

Yes, explain what effect it has on lateral G given the same speed.

If you're cornering with a given acceleration the lateral forces are identical. For the same acceleration (think circular motion) you will corner with a tighter radius if you are going slower.

What changes by hanging off your bike is vectors describing the forces acting on the bike.

See the attached image. Notice the difference in displacement between contact patch and center of mass for the guy sitting upright and the guy hanging off the bike - lean angle is identical. (I apologise for my lacking drawing skills...)

[avgas]

In a perfect world the bike goes down and lightly scrapes the pegs like a dish cloth on a fry pan and we all ride away like nothing really happened (only done it once on ZX4).
But sad reality is peg grabs NZ chunky tarseal and the see-saw happens lifting the weight off the wheels.

[Mental Trousers]

Yeah, my riding mates tell me I should hang off the bike more but I can't really be shagged. My developed style (good or bad), is shifting my weight to the pegs and maybe scootling my ass a little to the side that I am leaning, but I don't hang off the side of the bike, hence the peg scraping.

I read in "the Pace thread" that riding this way gives the appearance that you are going slower than you really are - cause you're not dragging a knee along the ground etc. and therefore good for calming/tricking other motorists and cops.

Good suspension set up will also of course avoid a lot of peg scraping action too - which you may have BTW!!

That sort of style is much better suited to road riding because you don't jump around as much. On the road it's only extreme cases where you need to climb way off the bike and stick a knee out, and that's only cos you screwed up or something unexpected has happened.

As for finding the edge of the tyres, my old girl would often start to feel vague in the front end (much like Death_Inc says) and she'd start to get get a small shake through the bars. On the Michelins it was very obvious when I'd ridden off the edge of the tyres as the whole bike would gently slide sideways the further I leant over. That was 1 of the reasons why I always use matched tyres - you get to the edge of them both at the same time. The Metzelers and Super Corsa Pro's I never found the edges.

[Ocean1]

If you're cornering with a given acceleration the lateral forces are identical. For the same acceleration (think circular motion) you will corner with a tighter radius if you are going slower.

What changes by hanging off your bike is vectors describing the forces acting on the bike.

See the attached image. Notice the difference in displacement between contact patch and center of mass for the guy sitting upright and the guy hanging off the bike - lean angle is identical. (I apologise for my lacking drawing skills...)

So, in spite of the separation of body and bike mass centrelines available lateral traction is unaffected, up to the point where leaning in will prevent the tyres exceeding their design limits.

If manufacturers develop tyre profiles and compounds which optimise traction at extreme angles are you not reducing available traction by keeping the bike more vertical? Doesn’t it make more sense to attempt to keep the bike on an angle where the tyres perform best?

[Mikkel]

So, in spite of the separation of body and bike mass centrelines available lateral traction is unaffected, up to the point where leaning in will prevent the tyres exceeding their design limits.

If manufacturers develop tyre profiles and compounds which optimise traction at extreme angles are you not reducing available traction by keeping the bike more vertical? Doesn’t it make more sense to attempt to keep the bike on an angle where the tyres perform best?

I'd say no to that.

I believe some road tyres use a harder compound in very narrow lean angles and have a softer compound for wider angles. And I guess this would make sense.

However, if you look at Stoner leaning in at 70° - that is pretty extreme to me. I doubt that racing slicks will have anything but soft compound rubber on them.

The way to look at it is this: The tyre grip (compound, design) does not dictate how fast you corner - it dictates how fast you CAN corner - i.e. how much lateral force you can apply to the road for a certain normal force. As you lean over further your normal force decreases since the weight is not sitting "on top" the contact patch. There fore, the more upright you can keep your bike for a given cornering speed the less risk you have of loosing grip.

[xwhatsit]

So, in spite of the separation of body and bike mass centrelines available lateral traction is unaffected, up to the point where leaning in will prevent the tyres exceeding their design limits.

I would guess that's not quite right. Your suspension would surely be working better with a shallow lean angle -- when you're leaned over, bumps are trying to shift the suspension up and down at a different angle to what it works at. So if you're more upright, your suspension can keep the wheels in better contact with the road, right?

[Mikkel]

I would guess that's not quite right. Your suspension would surely be working better with a shallow lean angle -- when you're leaned over, bumps are trying to shift the suspension up and down at a different angle to what it works at. So if you're more upright, your suspension can keep the wheels in better contact with the road, right?

There is that as well. Hitting a significant bump while on a lean upsets the bike much more than when upright.

We're talking riding on a theoretical flat surface here I assumed...

[Badjelly]

As you lean over further your normal force decreases since the weight is not sitting "on top" the contact patch. There fore, the more upright you can keep your bike for a given cornering speed the less risk you have of loosing grip.

That sounds dodgy to me, Mikkel. What do you mean by normal force? Normal to road? For a horizontal road, that's just the weight of the bike + rider.

[ipod1098]

skidmark will know. he scrapes his fairings..

[FROSTY:Me]

One thing not mentioned (I think) is that every tyre brand and within reason model has its own way of "announcing" its about to start to slide.
For example Michellen tends to go vague fairly early and slide progressively whereas Metzlers grip longer but let go with more of a bang.
--The tyre "experts" dont knot knickers these are examples only

[AllanB]

Did exactly that.

Got a cargo strap around the garage rafter and leaned it over to 45deg, scary. Then leaned it to the 55deg Mr Buell says is max. Is a good way to scare the crap outa oneself.

The thing here is that when riding you have your weight etc on the bike - looks cool in the garage but differs on the road. I presume the tyre guys lean angles are actual riding ones, otherwise they are pointless.

[Mikkel]

That sounds dodgy to me, Mikkel. What do you mean by normal force? Normal to road? For a horizontal road, that's just the weight of the bike + rider.

For a vertical bike on a horizontal road... yes.

Trouble is what happens at the contact patch when you are on a lean?

Not all of your weight is pushing directly down on the tyre - some is being balanced by gyroscopic forces as well.