It's fairly simple, though hard to explain without the use of graphics.
simplest way of doing it.
1: Weight Transfer from side-side is bad, as the tyres give most grip when they are evenly loaded. if (for example) a tyre has 120% of it's normal load on it, it won;t give 120% of it's normal friction. this is called Load Sensitivity.
2: Weight transfer in cornering happens because the C of G is above where the tyres contact the road, causing it to roll. (imagine pushing on one end of a pencil)
3: the amount of weight transfer is proportional to the angle between the C of G and the bottom of the tyre. Imagine a lever, going through the contact patch of the tyre and the C of G. The closer the lever is to being flat, the more you're pushing along the lever and the less you're trying to rotate it. so we want to push along the lever (and move the C of G round the corner) as much as mpossible, and not waste force pushing down (for an outside tyre), making the car roll.
4: 2 ways to this- Move the tyres out, or move the C of G closer to the road. from a dynamics point of view, these are the same thing. (actually, there's a third way, If you're only interested in turning left, move the C of G left)
The load sensitivity part probably doesn't really apply to solid slot car tyres- but it's still a noticable effect- try varying axle lengths in an otherwise unchanged car (unmagneted for the most noticable effect) , the wider the axle, the quicker it'll go round bends.
