2014 SX Tracks

[haggqvist]

What's the rationale for the .7 static friction? It should be higher than the sliding friction for most (probably all) surfaces.

Since I'm a structural engineer I've been thinking about traction not as a matter of simple coulomb friction between homogeneous surfaces but from a soil-mechanics perspective.
My initial low friction values are based on internal friction values for different soils which typically vary between 0.5 and 0.7 and as these values are proportional to the amount of shear stress the soil can withstand before the initial failure I think it describes the problem fairly well under the circumstances.
As for the higher values for higher slip rates; they are just based on the idea of the soil being compressed and therefor being able to withstand more shear stress before further failure.
I'm well aware of the flaws in the mechanics but imo it works great and gives a realistic feeling for loose soils like sand.
Having an initial low friction makes rougher tracks a lot more forgiving as well because the tires slide a bit before re-gaining grip when thing's go pear-shaped.

While we're on the subject; any chance you could separate the lateral and longitudinal friction values in the tileinfo?
Imo that would make it a lot easier to simulate sand and other loose soils.

[jlv]

I still think you want static friction to be the first peak, then drop off as it starts to slip and then ramp up again as the tire would have to move lots of soil to achieve that slip speed. I see a lot of tracks where if you park on a hill the bike will slowly slide down because the static friction is too low. There's no way that's realistic.

I could definitely make the lateral friction separate. I'm not completely sold on the idea that it should be different though. I'm going to have to make some kind of gauge to measure some real tires.

[Burkeen820]

The tracks are prime as it is lol just run it

[AWood]

The tracks are prime as it is lol just run it

[haggqvist]

I was mainly talking about the interaction between soft, uncompressed soil and a rolling tire at an angle, mostly the front wheel when turning, I guess I should have made that a bit more obvious.
The current system is fine for the rear wheel longitudinal traction imo and the only reason I would like the values separated is to avoid having to make compromises between lateral and longitudinal friction.

[alexsss9]

I agree Yamahaman's jump look way smoother and as big as JLV's one.
Maybe we should give it a try and do one supercross this year with those rounded top jumps???