Car Specifications
An adult derby can either be a formal affair regulated by the same rules as the Cub Scout Pinewood Derby, or it can be comedic and open to interpretation. One Scout pack held an adult Derby in which there were size rules but few others, with the cars even able to knock other cars off the track. Others are more specific and employee standard Boy Scouts of America rules. These rules include a total height of 4.5 inches, a width of 2.75 inches, a length of 7.0 inches and a clearance from the bottom of the wheel to the bottom of the car of 0.375 inches.
Car Weight
An informal Derby for adults might increase the weight limit above 5 oz., perhaps to 10 oz. or 16 oz. A more formal Derby would stick to the standard Derby weight of 5 oz. The most informal adult Derby might have no official limit on the weight, just to make sure that the car does not damage the track in any way.
Alterations
One of the rules of a standard Pinewood Derby is that wheels cannot be rounded, shaved, pointed or modified in any other way. The tire contact area of the wheels can have rough spots smoothed with sand paper. Nails can be polished and stamped to remove imperfections but the size and the shape of the head cannot be changed. These standards can be applied to an adult derby, but as in car specifications and car weight, a more informal derby may only require that the cars do not damage the track in any way.
General Rules
Adults may not have their sons make their cars for them. No messy or hazardous materials like liquids and gels can be used (dry lubricants like graphite only). Only the wheels can touch the track and no other method of propulsion other than gravity should be used on the cars. Cars must typically display their entry numbers somewhere on the car. Adults should exercise sportsmanship at all times.