Suspension set-up, ride height setting and checking tweak using standard rubber tires typically gives non-precise and non-repeatable measurements. Rubber tires with foam inserts are never perfectly round, so when checking and setting up suspension geometry, ride height or tweak it is important to have all four sides of the car to be exactly the same size and perfectly round. The aluminum set-up wheels are one of the most important and basic set-up tools when performing a professional car adjustment.