Team Dynamics Alloys

[C2K]

There is a number of benefits to reducing weight on a wheel/tyre assembly. Principally that is the reduction in rotating mass, and the need to accelerate/decelerate that mass (think why people fit lightweight flywheels). The rest of the benefits revolve around less force into the suspension from a bump or undulation, and less disturbance/effect on the tyre's contact patch - how quickly the spring can return the tyre's contact patch in the event of a dip, how little it varies is how much you can exploit what's available, which in racing could mean a greater corner speed....

I would advise you go and read about sprung and unsprung weights.