Position in seat?

[The Stranger:Me]

No such thing as "over thinking".

I see you haven't met pdath yet.

[R-Soul]

I see you haven't met pdath yet.

I am probably as bad or worse to be honest...

[Crisis management]

I tried answering this but it has got a long way from where the OP was asking about how weight affects handling (I think that was the question??) so I'm stopping now.

See if you can find some info on how Kenny Roberts teaches riding skills, that may be an easier way to explain it.

[p.dath]

I see you haven't met pdath yet.

Since you tempted me; I can't gree with most of post #75 that has been stated as "fact".
http://www.kiwibiker.co.nz/forums/sh...post1129712458

If he was drifting into the outside lane at 200km/h then it is just as likely it was because of the speed and not a loss of traction.

Leaning out when the bike leans in is completely pointless. This is just balancing the centre of mass (COM) again. If you want to turn you need to lean in the same direction as the bike so that the COM moves from being in line with the bike over to the side of the bike - in the direction you are turning.

Road bike tyres are curved (you'll notice the outside has a larger circumference than the middle). Just because you are leaned over doesn't mean your contact patch (aka traction) will be reduced, or that you are at more risk of going for a slide.

That's the short version of my thoughts.

[p.dath]

And while you have me going, I substantially disagree with this statement:

Leaning the bike over more allows it to make sharper turns at slow speed (when not counter steering)

Just to make it clear; counter-steering is the brief input you provide into the steering to commence a turn. Once the bike is leaned over you don't need to provide further input into the steering in the opposite direction unless you want the bike to lean over more/turn harder.

The lean angle required = arctan(v^2 / gr), where g=gravity and r=radius of turn.


As you can see from the formula above, if your speed is low, then the lean angle has to be almost 90% if you have a small "r"adius of turn. If you exceed the lean angle then the bike will simply fall over.

[Katman]

As you can see from the formula above,

[The Stranger:Me]

Since you tempted me; I can't gree with most of post #75 that has been stated as "fact".
http://www.kiwibiker.co.nz/forums/sh...post1129712458

If he was drifting into the outside lane at 200km/h then it is just as likely it was because of the speed and not a loss of traction.

Leaning out when the bike leans in is completely pointless. This is just balancing the centre of mass (COM) again. If you want to turn you need to lean in the same direction as the bike so that the COM moves from being in line with the bike over to the side of the bike - in the direction you are turning.

Road bike tyres are curved (you'll notice the outside has a larger circumference than the middle). Just because you are leaned over doesn't mean your contact patch (aka traction) will be reduced, or that you are at more risk of going for a slide.

That's the short version of my thoughts.

And while you have me going, I substantially disagree with this statement:


Just to make it clear; counter-steering is the brief input you provide into the steering to commence a turn. Once the bike is leaned over you don't need to provide further input into the steering in the opposite direction unless you want the bike to lean over more/turn harder.

The lean angle required = arctan(v^2 / gr), where g=gravity and r=radius of turn.


As you can see from the formula above, if your speed is low, then the lean angle has to be almost 90% if you have a small "r"adius of turn. If you exceed the lean angle then the bike will simply fall over.

I am probably as bad or worse to be honest...

Ya think you're worse? Honestly?

[R-Soul]

Since you tempted me; I can't gree with most of post #75 that has been stated as "fact".
http://www.kiwibiker.co.nz/forums/sh...post1129712458

I only stated four points as (what I think are) fact - which one is wrong? I have gone back ad numvbered them for convenience.

If he was drifting into the outside lane at 200km/h then it is just as likely it was because of the speed and not a loss of traction.

Very possibly- and because he was at an uncomfortable (MX style) position in which to execute counter steering.

Leaning out when the bike leans in is completely pointless. This is just balancing the centre of mass (COM) again. If you want to turn you need to lean in the same direction as the bike so that the COM moves from being in line with the bike over to the side of the bike - in the direction you are turning.

Actually for a given speed when the bike is equilibrium in a corner (i.e. not falling over more or less), the COM is fixed and does not move (remember the compnent . BUT, where the relative COM of each of the rider and bike is does make a difference (since you want the bike more upright for better suspension operation and therefore better traction). The further inward teh rider is, the more upright the bike is. But the COm of both the bike and rider stays the same.

Road bike tyres are curved (you'll notice the outside has a larger circumference than the middle). Just because you are leaned over doesn't mean your contact patch (aka traction) will be reduced, or that you are at more risk of going for a slide.

It is not the contact patch size that makes the difference. Its the operation of the suspension to keep that patch on the ground. There can be no traction when the wheel is in the air.

[aprilia_RS250]

And while you have me going, I substantially disagree with this statement:


The lean angle required = arctan(v^2 / gr), where g=gravity and r=radius of turn.

.

I think that function spits out g force not lean angle...

[aprilia_RS250]

And while you have me going, I substantially disagree with this statement:
The lean angle required = arctan(v^2 / gr), where g=gravity and r=radius of turn.
.

I may be wrong but I think that function spits out g force, not the leaning angle required...

[p.dath]

I think that function spits out g force not lean angle...

Nope, lean angle.
http://en.wikipedia.org/wiki/Counter...o_lean_to_turn

[Katman]

Fuck it - I'm selling the bikes and taking up stamp collecting.

[R-Soul]

And while you have me going, I substantially disagree with this statement:


Just to make it clear; counter-steering is the brief input you provide into the steering to commence a turn. Once the bike is leaned over you don't need to provide further input into the steering in the opposite direction unless you want the bike to lean over more/turn harder.

The lean angle required = arctan(v^2 / gr), where g=gravity and r=radius of turn.


As you can see from the formula above, if your speed is low, then the lean angle has to be almost 90% if you have a small "r"adius of turn. If you exceed the lean angle then the bike will simply fall over.

No you misread my post - I meant when NOT counterstering, and at low speed. For example when making a tight circle in a car park at close to walking speed. When you are doing this, the correct technique is to turn the bike steering in the direction of the corner, and then lean the bike over in the direction of the turn. Since its low speed, the functioning of the suspension is not an issue, and when the bike is leaned over, a smaller turn radius is possible.

Similarly, when dirt biking on small radius slow corners (eg hairpin), you can either do it that way, or break traction at the back wheel and align the back wheel to face slightly inwardly, so that the forward scrabbling traction of the back wheel has both a forward and inward component.

[sinfull]

Must be time for me to give up riding, You have to be a mathematician to know how much to lean into a corner now !

[R-Soul]

If he was drifting into the outside lane at 200km/h then it is just as likely it was because of the speed and not a loss of traction.

I thought about this some more. There may not be catastrophic loss of traction, but when teh suspension is not working correctly, it "skips" into the air with miniscule jumps every time it hits a small bump. The combined effect of many small skips while the bike is being pushed outwardly in a corner, will cause the bike to run wide, necessitating a harder countersteering input and a therfore a harder lean angle (which means the suspension performs even worse, creating a bit of a downward spiral).