Prototype gp500 physics model

[EdouardB]

Yes I was talking about how controllable (or not ) it is.

Thanks for the graph, pretty awesome stuff.

[EdouardB]

I also would like to add that I am NOT pretending to be some GP rider or anything. I'm just an amateur who is fortunate enough to have ridden some unusual bikes on the track and I'm not crazy fast. And I don't want to sound like a "know-it-all", because I simply don't know it all.
I'm just trying to give my feedback to try to improve the game

[girlracerTracey]

I also would like to add that I am NOT pretending to be some GP rider or anything. I'm just an amateur who is fortunate enough to have ridden some unusual bikes on the track and I'm not crazy fast. And I don't want to sound like a "know-it-all", because I simply don't know it all.
I'm just trying to give my feedback to try to improve the game

I think your contribution to this discussion is a very worthy EdouardB particularly bearing in mind your experience in riding so many assorted racing motorcycles.

In defence of the gp500 pc game I wouldn't personally call the ability to power-slide and rear wheel steer in the game "ridiculous" but I would describe it as exaggerated from real life. I think if you wish to experience the "ridiculous" look no further that Milestone's motogp13/13 games..

As BOBR6 rightly says I am new to the gpbikes simulation and I have a lot to learn. I fully accept that.

I am going to take a back-seat on this discussion and listen to those who are more qualified to comment than I am. Both from the perspective of real life racing and from more advanced experience of gpbikes. However I do think this is a very interesting discussion.

grT

[EdouardB]

I think if you wish to experience the "ridiculous" look no further that Milestone's motogp13/13 games..

I tried the demo. The powersliding was so ridiculeous that I actually had a good laugh playing the game

[HornetMaX]

Thanks for the graph, pretty awesome stuff.

I think I have now found the proper reference to understand the parameters of Piboso's tire model.
I can draw the equivalent graph for GPB tires (graphs actually, as the above is only for longitudinal slip).

I also would like to add that I am NOT pretending to be some GP rider or anything. I'm just an amateur who is fortunate enough to have ridden some unusual bikes on the track and I'm not crazy fast. And I don't want to sound like a "know-it-all", because I simply don't know it all.
I'm just trying to give my feedback to try to improve the game

I personally have zero track experience, so I'll always listen to whoever has done even a single lap on a track.

I am going to take a back-seat on this discussion and listen to those who are more qualified to comment than I am. Both from the perspective of real life racing and from more advanced experience of gpbikes.

Don't  ! I think it's useful to have the point of view of people who just discovered GPB: most here have followed GPB development for years, so our point of view may be a bit biased.
And from the comments I've read, I think you're more qualified than a fair share of old timers here. I won't name names though

But try not too focus too much on the 500cc: it's surely the hardest bike to ride in GPB and it has some problems that need to be fixed.

MaX.

[Allen]

EdouardB , highly simplified, two strokes tend to have a smaller, peakier power band to play with that probably makes it harder to hold a controlled slide... having said that, it does depend an enormous amount on what the tyres are designed to do whilst sliding, a radial should be worse in that regard and usually a little bias ply helps. In tyre terms I'll take a tyre with a good feel and a forgiving nature over a tyre with slightly better peak grip and fall off a cliff slide, any day.. Take the TZ350, depending on how the one you've ridden was set up (what pipes, carbs and barrels etc) it could be anything from reasonably docile to extremely peaky (the one I rode had Lectron flat slides, F Barrels, and F2 pipes that gave it a nice easy power delivery, when we ran it as a 250 it was on original pipes (G Barrels and a smaller set of lectrons) and was really quite peaky. My Armstrong on the other hand I always ran with the peakiest power delivery it gave (wider opening disc valves and a set of pipes with a narrower power band for more top end), but it was always easier to control slides with the Rotax engine, possibly due to the fact it fires both cylinders at the same time (effectively like a 250 single)
I never raced 4 strokes (the only 4 stroke I ever took on track was a classic 250 K2 Honda with around 25-30bhp.. still outran a YVPS 350 Yamaha around Snetterton.. actually I tell a lie, I did intend to race a CBX550, but gave it up as a bad job after testing it once... and the thought of the cost of rebuilding if I bent it put me off)... but the majority of my road bikes have been 4 strokes and I have been known to get the back end moving about whilst riding on the road (I'm not really a nutter, I just like riding fast)

Max, the graphs, yep wonderful, but it's extremely hard to measure anything other than longitudinal grip/slip for obvious reasons, that doesn't mean that same slip/grip doesn't apply in any other direction. Simply put, if your tyre is spinning (so it has any longitudinal slip) and the bike is leaned over, it's pretty much a given that the tyre must be moving sideways as well (would be lovely if it didn't as you would never be able to get high sided!). It is possible that the grip fall off needs to change (again you can exchange peak for fall off and get a better, more forgiving tyre that is just as fast but easier to cope with (so more sliding but less falling off).
At the end of the day you can do as much maths as you like, it doesn't really help to get to a point of being able to "ride" better in a sim with no haptic feedback.. and riding a bike really is all about feel (dumb as it may sound, I'd really like to see some feedback, and the removal of the limit on lean angle... if I want to ride off the edge of the tyres, I should be able to.. but I should get enough feedback to tell me I'm about to, so I don't... )

[EdouardB]

Allen, thanks for the reply. The TZ350 I ride is completely original (including carbs) and very very peaky (it's perfectly tuned though), much more than the 1992 TZ 250 (V2) I also ride. The 250 though has reed valves and exhaust valves (stock), which help tremendously with making the engine have more mid range and somewhat easier despite having much more power than the 350.
Having said that, even on the 250 I don't make the rear slide much at all. It's way harder to slide than my R6.

I agree about the haptic feedback but I don't know how Piboso could recreate the feeling of being on the max lean angle (that mix of high grip and slight sliding at the same time is complicated to do on a PC controller)

[HornetMaX]

Max, the graphs, yep wonderful, but it's extremely hard to measure anything other than longitudinal grip/slip for obvious reasons

Well actually these quantities get measured a lot. It's thanks to these measures that you can end up with a Pacejka tire model (like the one used by Piboso games).
Tire makers and researchers have facilities to carry out this kind of measures (pure longitudinal slip, pure lateral slip, combined long/lat slip, at different normal loads, at different camber angles, etc).

that doesn't mean that same slip/grip doesn't apply in any other direction

Never said that, of course.

Simply put, if your tyre is spinning (so it has any longitudinal slip) and the bike is leaned over, it's pretty much a given that the tyre must be moving sideways as well.

Sure, but it is also true that your tire could be slipping laterally with little longitudinal slip. But yeah, usually you have lateral and longitudinal slip together.
The only thing I was saying is that saying "I want to slip 5%" is a coarse simplification.

It is possible that the grip fall off needs to change (again you can exchange peak for fall off and get a better, more forgiving tyre that is just as fast but easier to cope with (so more sliding but less falling off).

That is exactly what I intended to try (if and when, cause it sounds damn hard): a more forgiving tire could help sliding in a more controllable fashion. But I also said that I'm really not sure if that would be enough.

At the end of the day you can do as much maths as you like, it doesn't really help to get to a point of being able to "ride" better in a sim with no haptic feedback.. and riding a bike really is all about feel

I guess we agree on the fact that the lack of feedback is the main responsible of why it's hard to slide controllably in GPB (I said it in my very 1st post on the subject).
That said, I can't rule out the possibility of providing more slide control than what we have now, despite the fact I'm not sure I'd like to have it.

(dumb as it may sound, I'd really like to see some feedback, and the removal of the limit on lean angle... if I want to ride off the edge of the tyres, I should be able to.. but I should get enough feedback to tell me I'm about to, so I don't... )

I'm not against some additional feedback at all (maybe for knee down, maybe for rear sliding, don't know), but that's entirely up to Piboso.
The removal of the lean limit could be interesting too, but again it's something only Piboso can do.

MaX.

[Allen]

Max, I meant measuring slip whilst actually riding, I realise tyre manufacturers have all manner of slip measurements they can make.. I'd hate to think anyone tried to develop a tyre on just guess work and seat of the pants feel

[HornetMaX]

Max, I meant measuring slip whilst actually riding

Oh that ... well yes, no direct measure. But I'm sure the sophisticated ECUs do have a mean to estimate that, so even this info is potentially available on-board.

MaX.

[BOBR6 84]

I also would like to add that I am NOT pretending to be some GP rider or anything. I'm just an amateur who is fortunate enough to have ridden some unusual bikes on the track and I'm not crazy fast. And I don't want to sound like a "know-it-all", because I simply don't know it all.
I'm just trying to give my feedback to try to improve the game

I think your contribution to this discussion is a very worthy EdouardB particularly bearing in mind your experience in riding so many assorted racing motorcycles.

In defence of the gp500 pc game I wouldn't personally call the ability to power-slide and rear wheel steer in the game "ridiculous" but I would describe it as exaggerated from real life. I think if you wish to experience the "ridiculous" look no further that Milestone's motogp13/13 games..

As BOBR6 rightly says I am new to the gpbikes simulation and I have a lot to learn. I fully accept that.

I am going to take a back-seat on this discussion and listen to those who are more qualified to comment than I am. Both from the perspective of real life racing and from more advanced experience of gpbikes. However I do think this is a very interesting discussion.

grT

Didnt mean to diss-hearten anyone!
I was litterally speaking for myself!

+1 what max said!

Besides, I suck at gpbikes.. Also I only race a 2001 yamaha R6 (carb model) no tcs, no electronics at all. Throttle response is hit or miss lol. 1 thing that is for sure.. On my bike anyway.. Tyres make a HUGE difference!! Its certainly not moto gp.. or a gp bike but when I used bridgestones my bike was sliding everywhere.. Into and out of corners! I use pirelli diablo supercorsa or dunlops now and I feel planted.. Still get slips and slides but that comes with the territory..

Been playing gpbikes the last couple of days and getting really frustrated with it..
For me personally I think gpbikes has more ''front end'' and track surface/elevation issues to sort out first..

[girlracerTracey]

Oh bless you Bob  Don't worry I'm not disheartened. I just try to realise in myself when I have given everything that I can give on any given subject..and then shut-up! lol. To give everyone else a rest from my opinions.. You're a fast guy in real life and in m/c racing sim.s. I respect your opinion. 

You guys have played gpbikes much longer than I have and you guys also race /do track days in real life. I have raced but only as an amateur and only a couple of times.. I am a complete novice in that respect. Plus Max is really knowledgeable on engineering and motorcycle science and I'm not..

So I am not disheartened. I am listening intently to what you guys have to say..

Been playing gpbikes the last couple of days and getting really frustrated with it..
For me personally I think gpbikes has more ''front end'' and track surface/elevation issues to sort out first..

If you don't mind doing so can you elaborate a bit on your front end and the track surface/elevation issues? I am intrigued by what the problem(s) might be.

grT 

[BOBR6 84]

Yeah sure..
Before I say anything il just point out this could be down to my bike setup, lines, and things like having rider weight l/r auto/manual.

Some tracks when I turn into the corner the front wheel just washes out.. Especially on uphill turns! When you have some lean angle and start going uphill, it just washes out unless you take a wide entry to square it off.. Which is slow and boring.. I want to attack the corner!

Some tracks you can get away with it but it also feels like there is some ''other force'' pulling the bike up and around the turn? Cadwell park for eg, strange things happen there..
Again some people say (myself too) the front end issue isnt as bad with manual rider l/r lean!

So f+#k knows whats going on? Lol

[HornetMaX]

Search no more, it's a known issue. Very visible on corners with slope and/or bank.

Using manual rider lean L/R seems to reduce the impact.

MaX.

[BOBR6 84]

Search no more, it's a known issue. Very visible on corners with slope and/or bank.

Using manual rider lean L/R seems to reduce the impact.

MaX.

So is it a track problem or physics/rider movement problem? Or combo of both?