Top Speeds and Engineering Feats in Soap Box Derbies

Soap box derby racing, while gravity-powered, has pushed the boundaries of speed and engineering through innovative designs and materials.

The top 3

Guinness World Record for Fastest Soapbox Speed: The fastest speed achieved in a soapbox is 137.78 km/h (85.61 mph), set by Guy Martin (UK) at Mont Ventoux, France, on October 16, 2014, over a 2 km stretch of road.
Engineering Innovations for Maximizing Gravity-Powered Speed: Competitive soap box cars utilize aerodynamic designs, precise weight distribution (often in the rear for speed), low driver positions, and optimized wheel materials and profiles to minimize drag and rolling resistance.
Portland's Adult Derby Speed Records: On the Mt. Tabor course, homemade racers in the Portland Adult Soapbox Derby can reach speeds of around 50 mph, with the current track record set at 71.10 seconds by Justin James of Team Rusty Rocket in 2015.