Originally Posted by Char1ie

Unsprung weight is important. In the most basic terms a lighter wheel/hub/brake combination can have a big impact on handling. My experienced racing mate puts it simply - times the weightloss by three if you are removing mass from the wheels. So I am taking 6kgs out of the weight of my wheels, and 3.6kg from the brakes (see below), for a total of 9.6kg which is effectively nearly 30kgs handling improvement.