Max lean angle

[HornetMaX]

Hi all,

searching for something in the forum I stumbled on an old post in which Piboso said:

The max lean angle is automatically estimated by the "virtual rider" using the lateral grip the tyres can generate at the moment ( compound, temperature, wear, wet, groove, marbles and road banking are used as inputs ).

All is OK in the above, but it made me think: could it be that when the road banking changes quickly, the virtual rider tries a bit too hard to pick up the bike, making things worse and losing the front ?

For example, on Victoria on turn 10 (right hander after Lucky Heights): you're going down before the turn, there's no banking. But as soon as you turn right to go towards the apex, you are "crossing" the track slope, so it's like having some banking (and when you're in the turn the banking changes again, going back to "no banking").
I'm aware there are ways to take this turn to avoid that, but I find it a bit too easy to lose the front there (nothing new, it has always been there as far as I can recall): you're at very low speed, no significant brakes or throttle applied, and still ...

I remember that Piboso once acknowledged that there's a problem in banked turns, it would be nice to have more details.

MaX.

[PiBoSo]

No problem with banked turns.
There is a problem with turns up and downhill.

[HornetMaX]

No problem with banked turns.
There is a problem with turns up and downhill.

OK, the two are tied though, no ? When you have a banked corner and you "cut" it (i.e. you;'re not following the mid-track line), you are going up/downhill. And vice-versa.

Anyway, is the origin of the problem known ? Is a solution possible ?
The issue being fairly visible on the default track, it's a bad for people trying the GPB demo.

MaX.

[Hawk]

This is something I have been aware of during my time with GPB, but although there is a problem with uphill and downhill turns I believe the banked turn problem you are talking about is a bike physics problem that can be solved by good bike physics files... and good bike setup.
I say this because the new Honda RCV(the Noss69 release) copes flawlessly with a banked uphill turn, it's the only bike released that I know can do this. So you've got to ask yourself were the real problem actually lies? Is it with the bike physics files or the core programme physics? I have to say that I now believe this problem lies with the bike physics files and not with the core programme.

The test I did to come to this conclusion was the right hand turn just after going under the bridge on "Silverstone V0.94_NDS"; this turn rises up and is slightly banked; the Honda RCV is the only bike released that you can take that with absolute confidence that the front end will not wash away.

Hawk.

[BOBR6 84]

When we exit the pit garage and turn at low speed the bars shake violently.. Sometimes its enough for the bike to flip over lol. Why does that happen?

Maybe its the same problem on these up/down hill turns..

[BOBR6 84]

Could it be the suspension? How it compresses with lean angle..? Making the tyre work too hard or even not hard enough?

As Hawk said.. The honda is fine! But I think that has very stiff steering damping.. Or thats how it feels to me compared to other bikes..

[HornetMaX]

I'll be back home tomorrow and I plan to spend some time to try to isolate what makes such a big difference on the Noss' RCV compared to the murasama: the 1st never falls in turn 10 at Victoria, no matter the trajectory, while the 2nd falls 95% of the time (and 100% of the time on some trajectories). It's just very very weird.

MaX.

[BOBR6 84]

Maybe there is no problem?

In GPB when we ride around the circuit we control the bike leaning left and right and the lean angle is always the same.. It only goes so far..

So when the bike is leant over and we come to a slight hill the lean angle increases.. So we are off the edge of the tyre?

So.. Maybe the real problem is the control...?

We are unable to sit the bike up without turning.. Or (its the same control as turning)

I hope somebody can make sense of that lol.

[HornetMaX]

@BOB: well, Piboso seems to be aware of at least one issue, so I'd tend to think there is a problem.

What you say makes sense, but even if the issue is in the control part (which could be), well ... there is an issue.

Still, if some bikes do not have the problem (and that's the case), would be nice to know exactly why.

MaX.

[Hawk]

@BOB: well, Piboso seems to be aware of at least one issue, so I'd tend to think there is a problem.

What you say makes sense, but even if the issue is in the control part (which could be), well ... there is an issue.

Still, if some bikes do not have the problem (and that's the case), would be nice to know exactly why.

MaX.

Has anyone thought of asking Noss how he achieved this? Seems the next logical step to me rather than re-inventing the wheel(so to speak) and trying to test to find out for yourself. 

Hawk.

[HornetMaX]

Has anyone thought of asking Noss how he achieved this? Seems the next logical step to me rather than re-inventing the wheel(so to speak) and trying to test to find out for yourself. 

If I recall correctly, we discussed briefly once, without really digging everything up.
Anyway yes, I've posted on the french forum  about all this, of course

MaX.

[HornetMaX]

Is that related ?

http://forum.mx-bikes.com/index.php?topic=740.msg10944#msg10944

MaX.