I did some trials on tyres to see what was the best operating range and came up with 65 Celsius (149 F)
F1 tyres operate around 100C
The problem is getting the tyres to 80-90 C in normal UK conditions
If the initial tyre temp is 15C (288K) and your initial pressure is 1 bar then a rise to 90C (363K) is a rise of 26%
This means that when you come in your tyres will be at a pressure of 1.26 bar (18ps1)
This is above the optimum pressure for the contact patch (which seems to be 16psi with the driver on board)
Best grip is a balance between mechanical grip (the size of the contact patch * the friction strength of the tyre) and the chemical grip (stickiness of the tyres), stickiness increases with heat.
What I found was that above 65C the stickiness increased but the tyre strength decreased, so you lost more mechanical grip than you gained chemical grip.
But, just to make life more interesting, if you drive smoothly so you don't exert maximum mechanical stress, then you would get more grip as you got hotter.
One cause of hopping is thought to be the fact that as you load one tyre, it gets hot enough for the rubber to 'melt' and the loss of mechanical strength is what caused the tyre to jump sideways until the stress eases enough for the tyre to hold again.
Seat stays are supposed to work by exerting pressure on the inside of the tyre, limiting the lift and enlarging he contact area, thus increasing the total mechanical grip and preventing the rubber from giving way.
So you only have to find the right operating temperature for your rubber, the right pressure for your best contact patch given your style of driving and then adjust the kart set-up so you
get optimum combined mechanical and chemical grip for that track under immediate track temperatures.
Can't be that difficult! (20 years and still searching)
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Bridgestone YDS Slicks Temp Range by 'SmoothAsSilk' (04 Apr 2015 @ 15:30)
