Hello,
Is there any chance to have, in futur beta of gpbikes, a more realistic thing, sorry i search my terms in french to:):
When i hear new gp motorcycle( i don't know if it was so much with old 500cc), more the bike takes angle more the rpm rise, because the point of contact between the tyres an the asphalt becomes a smaller circle than when the bike is straight.
ie it changes the transmission ratio.
Have you an idea if it will be possible to have this upgrading later?
I think it can help for braking, acceleration, and if no it can be more realistic.
Thank you.
I'm not 100% sure but I think this is already taken into account.
Not sure it's that visible though: I haven't done the math but first sight seems strange you can hear/see the difference.
MaX.
Quote from: janaucarre on June 12, 2014, 06:22:55 PM
Hello,
Is there any chance to have, in futur beta of gpbikes, a more realistic thing, sorry i search my terms in french to:):
When i hear new gp motorcycle( i don't know if it was so much with old 500cc), more the bike takes angle more the rpm rise, because the point of contact between the tyres an the asphalt becomes a smaller circle than when the bike is straight.
ie it changes the transmission ratio.
Have you an idea if it will be possible to have this upgrading later?
I think it can help for braking, acceleration, and if no it can be more realistic.
Thank you.
Thank you for the report.
Radius calculation will be fixed in Beta5.
That will be an incredible addition.. 8)
On circuits like the ulster gp and TT mini especially!
Good good good !
MaX.
what does this changes, in poor words? :)
Thank you Mr PIBOSO:) Great news, i think about that from many months.
When you lean the bike, the part of the tire you ride on has a smaller radius (compared t the radius in the middle of the tire).
I'm not sure it makes some sort of difference to the feeling. It's something that in real life can be used for example to estimate in an indirect manner the bike lean angle.
MaX.
understood, an update of the radius calculation really makes sense to me :)
Wow maximum realism :o
Good to read Piboso answers 8)
This would only effect modern bikes
Needs to be added in a way that works less for older bike tyres
Quote from: Ian on June 13, 2014, 12:53:39 PM
This would only effect modern bikes
Needs to be added in a way that works less for older bike tyres
Why it would only affect modern bikes ? It affects any bike.
MaX.
I confirm in real life it does on every bike (modern or old). It does change a little bit from bike to bike (depending on tyre profile), but barely noticeable.
The change of RPM however is very noticeable, and does change shifting points and stuff like that (on some tracks you upshift before the turn because otherwise you hit the rev limiter when you lean the bike and it's very uncomfortable). It's especially noticeable sound wise on 600s because of how high the RPM is.
Really happy for this to be in GP Bikes soon :)
Quote from: EdouardB on June 13, 2014, 03:27:54 PM
I confirm in real life it does on every bike (modern or old). It does change a little bit from bike to bike (depending on tyre profile), but barely noticeable.
The change of RPM however is very noticeable, and does change shifting points and stuff like that (on some tracks you upshift before the turn because otherwise you hit the rev limiter when you lean the bike and it's very uncomfortable). It's especially noticeable sound wise on 600s because of how high the RPM is.
I know it's a long shot, but do you have any numbers you recall exactly ? How many more RPMs a given bike was taking when leaning, stuff like that.
MaX.
It's very complicated because you're almost never at a constant speed on racetracks (always accelerating or braking)... The closest I can think of is the uphill left hander at Folembray, but the lean angle is not very big. About +1k RPM on a 600 maybe (if you watch MotoGP, it's extremely noticeable at high lean angles). I would not be surprised if it reached +2k RPM (or more) on a 600 when it's a really high lean angle. It's very noticeable on track. Even some beginners with low lean angles notice it.
It's very easy to calculate if you measure a tyre however.
Another effect of it is that when you pick the bike up at the exit of a turn, the RPM doesn't rise as fast!
Look at this video with this in mind, it's so noticeable when he changes direction left/right. Also, I want to add that the fact that their RPM drop so much at the entry of the turn despite leaning the bike over means they are really, REALLY braking hard.
https://www.youtube.com/watch?v=WELoKmv0DCo
I was asking because the calculated value for for GPB tires (990 bike) is huge: 20% smaller tire radius @ 60 degrees lean ! That's a lot of extra RPMs ...
It could be because GPB assumes a circular tire profile while in reality the profile could be flatter (flatter than a perfect circle I mean).
MaX.
First of all, while the profile of a slick tyre (or even a supersport DOT race tyre) is a lot pointier than a street tyre, it s not completely round. It's very round at the top, and the tyre goes flatter at the edges, to provide a lot of contact patch, like this (asymmetrical compounds FTW lol):
http://media.crash.net/original/340268.jpg
Second of all, they reach the edge of the tyre through tyre deformation and not through pure lean angle. What I mean is that the circumference you should consider is about 2 cm away from the absolute edge of the tyre. The tyre will be deformed and the edge will be on the ground as well in real life. See what I mean? Besides, on some tyre profiles, I've seen national level racers with a 2/3 mm chicken strip on the front tyre (the rear deforms more so usually no strip). The profiles are that extreme. With no tyre deformation we would probably have chicken strips.
You could say "OK Ed, but since the tyre compresses it reduces the radius right?" And you would be right, but it also happens in a straight line so I m ignoring that since we're looking for a ratio here.
You could also say "OK ed, but the edge of the tyre is still on the ground, it inflicts rotation on the wheel, so why are we taking the circumference 2cm away from the edge?" Well, you can have the same reasoning for the beginning of the contact patch towards the center of the tyre, so you take the middle of the contact patch. About 2cm way from the edge. Yay
Having said all that, after these corrections, I would not be surprised if the ratio is still 12 to 15% on a motogp bike, it sounds pretty normal, it's really noticeable and is part of riding on racetrack (in magny cours for example some riders change their lines to lean less so that they don't reach the limiter in 6th!)
You should see what I mean on this picture more easily
http://images.motorcycle-usa.com/PhotoGallerys/valentino-rossi-motogp-assen-20.jpg
You can really see it on the front tyre, and it's the same in the rear.
Is piboso reading this by the way? This is important stuff haha. :D
Thanks EdB :)
If I just measure the 1st picture, the ratio between the outer diameter and the central one is roughly 0.76, so even more than what I have in GPB.
Tire deformation is taken care of somewhere else but I see what you mean, it has an impact on the loaded radius, hence enters the computations we're discussing here.
As Piboso already has the notion of loaded radius (also dependent on the tire rotation speed), it should be possible for him to consider this (if it's impact is significant on the radius change).
MaX.
Instead of doing the ratio between the middle and the absolute edge, try using the middle of the flat side on the right part of the tyre (his tyre has worn out in a flat surface on the right). You'll get more than 0,76, that's what I meant!
I'm guessing (I haven't measured, I'm not on my computer) that you will obtain about 10 to 15%, which is what we observe at the track ( Iit can be 2k rpm on a 600 easily)
I just measured on an onboard video I did with the 600: my speed on the dashboard goes from 195 to 218 when leaning over (so about 12%) and that's just at about 40° (it's not a big corner). We can expect more than 15% at 60° lean easily! Probably around 18
OK, all seems to indicate that 20% at 60deg is not out of the ballpark.
I just realized that I can modify my plugin to show side by side the speedo speed and the real bike speed (as if it was measured by a GPS).
Can't work on it right now (and tonight the silly italian team plays against the even sillier english team), but that should show what GPB is doing right now and, probably more interestingly, what GPB will do in beta5 after Piboso has fixed this.
Will show what I find.
MaX.
Well, at the moment I see no change at all: the speedo speed and the "GPS" speed (speed of the COG) are identical.
So I'd say there's no radius change due to lean at the moment in GPB (which in fact was already pretty clear as there's no RPM increase).
MaX.
Not many people seem to be excited by this..
I cant wait for this to be applied!!
I think it will have a big effect on the bike handling.. But even if it doesnt it will still make the gpbikes experience more emersive..
Flicking the bike right to left vice versa will be awesome with the suround sound pumped up :)
me too :D