Originally Posted by ottoman
I am new to 12th scale and I have a question... I had a set of Jaco rear tires on my car. I bought a differnt brand of rear tires and I noticed that on the Jaco rim the mounting flange is flush with the edge of the tire and the new set has the mounting flange set inside the tire .120. This will narrow the rear track width of the car by almost a 1/4 inch. How will this affect the handling of the car? Do you use track width as a major tuning option?
Track definately affects handling dramatically. Before you even start playing with track width, its really important that your wheel spacing is even from the centerline of the car. Uneven wheel spacing can make your car feel as though it is tweaked. Also, when adjusting track width, check your endpoints afterward. The turning radiuses can change unevenly if the spacing of the rear tires changes relative to one another.
A wider track width will transfer less weight laterally at the back of the car. Widening up the car can free it up. Conversley, a narrower track width will transfer more weight laterally and make the car be pushier. Basically, the farther away from the chassis centerline the tire is, the less leverage the chassis has on the outside tire when it is cornering, thus pushing down on it less.
You can also add shims to the front of the car as a tuning option. A wider track at the front will make the car be more stable and pushy, a narrower track will make the car more agressive and steer more.