Originally Posted by jonestr

At a macroscopic level friction is independent of surface area. Although this sounds counterintuitive, it can be viewed in the following way: if you take some surface area and apply some weight to it then you get a certain pressure. If you take the same material and extend it over a wider area with the same weight then you have lowered the pressure so even though you have more area, which you might equate to more friction, you are simultaneously lowering the pressure so that the effect of larger surface area is cancelled by the lowered pressure.

What may make a wider tire harder to skid is that it is heavier which will increase the flywheel effect of rear wheel, i.e. increased rotational inertia, and for the same speed you will have to counter a larger rotational inertia which will cause you to have to apply more torque than you normally would. You might quantify this by conserving angular momentum.