The development of SmartTreads™ in the late 29th century greatly accelerated the development of the racing machines used in the Planet Racing series. Prior to SmartTreads™, different tires would have to be mounted on the machines to cope with the varied conditions under which the racers competed -- knobbies for dirt and mud, paddles for sand, slicks for pavement, and so on.

SmartTreads™ changed all that. An outgrowth of the rapid development of microdevices, or nanotech, SmartTreads™ allowed the actual surface of the tire carcass to change shape on the fly, according to the inputs of the riders. In other words, if a race started off dry on pavement and ended up wet in dirt, the rider could command the tires to change shape to fit the racing surface. The default setting of SmartTreads™ is a micro-groove -- to the naked eye, a racing slick. In use, the default state only changes at the tire's footprint, which itself can be modified to a point by the riders.

The advantage of this system, especially in a muddy race, is obvious: as the wheel spins and the tire rotates, the SmartTread™, operating at the blinding speed typical of nanotech, changes the smooth tire surface to a knobby one an instant before that section of the tire rotates into contact with the ground. Then, after that portion of the tire has dug in, transferred its share of the energy required for forward movement, then rotated on, it reverts to the default smooth state -- and the mud doesn't stick. Essentially, it becomes a self-cleaning tire.

Coupled with automatic sensors, SmartTreads™ have become ubiquitous on almost all wheeled ground vehicles. The racers, however, do not depend on their sensors to determine the right tread pattern for their SmartTread™-clad wheels -- they utilize their almost supernatural riding skills to make the proper choices as they are blasting along, choosing the right treads by "seat of the pants" inputs.