Pit bikes are small motorbikes that participants in powersports events use to ride around the pits, which are the staging areas where team support vehicles are located. More recently, they have been used in races held on either supercross or motocross tracks. Numerous performance and aesthetic upgrades are often applied to pit bikes.

Originally, there was only one way to acquire a pit bike. A rider would buy a child's minibike, usually a Honda CRF 50 or Kawasaki KLX110, and apply all the necessary upgrades and modifications to build a competitive pit bike. Of course, a rider could also buy a used bike. Since 2004, manufacturers have begun designing, manufacturing, importing, and selling already complete pit bikes. These bikes are less expensive, and require less time to complete.

Pit bikes are powered by 4-stroke, horizontal, single cylinder engines ranging anywhere in displacement from 49 cc to 195 cc. A typical pit bike is usually a small dirt bike, but it has become common to be able to buy pit bikes with street-style wheels and tires. Pit bikes with street tires, as opposed to knobby tires, are used in Mini Supermoto Racing.

Pit bikes are frequently heavily customized with decorative add-ons and performance-enhancing parts. Many riders and mechanics bore-out or replace engines in order to increase displacement and therefore power output. Heavy duty suspension systems, are often a necessary addition, since the stock mini-bike suspension was designed for a small child. Wheel, brake, and tire upgrades are sometimes performed to improve handling.

Pit bikes also have their own separate competitions held with classes generally corresponding to wheel size. This is a notable difference from Motocross and Supercross competition, where classes are separated by engine displacement. Pit bike racing is a relatively new niche of motocross, and as such, there is no official governing body similar to the AMA.