Build the World’s Fastest Pinewood Derby Car

How to Dominate Cub Scouts with a Rules-Legal Pinewood Derby Car, Using Science!

Anyone who’s ever met a Cub Scout knows about the pinewood derby, it’s arguably the coolest thing they do. Well it’s the coolest indoor activity they do at least. The idea is, kids all get an identical block of wood to build a car, with their Mom or Dad as a helper / mentor. Usually Dad gets carried away, takes over the build, and our Cub Scout is left with the extremely important (cough…Bu!!$#it) task of “sanding” the final product.

I personally was a Cub Scout from age of 6 and I had both a Grandfather and an Uncle who jumped at the opportunity to help build cars with me. Yes, I did a heck of a lot of sanding. Unfortunately, we were 100% aesthetically focused. Our cars were total duds on race-day. I believe they call these “trailer queens,” they were all show and no-go!

What we never understood was the physics to maximize speed of the wooden car on our sloped track. Each Cub gets the same block of pine, wheels and axles and nails. The rules dictate maximum dimensions of the car body, as well as maximum wheel base and weight. So the trick is maximizing all of the dimensions to get the fastest car. Without even watching the video I can tell you I got my butt-kicked by the kid with the wedge “doorstop” on wheels every year!

Mark Rober does an awesome job of breaking down all the variables that generate the most speed. He even consults with an actual physicist to determine the prefect recipe fir pinewood success! It’s all about correctly converting potential energy into kinetic energy. Just like real-world auto-racing, that’s all about center of gravity and weight-transfer. By correctly placing weight in the vehicle, a smart builder will GAIN potential energy and thusly kinetic energy! Dang! Why didn’t 8-year-old me know this science!

7 Key Steps to Pinewood Derby Success:

1. Max weight ~1″ in front of rear axle
2. Reasonably aerodynamic
3. Ride on 3 wheels
4. Lightweight wheels
5. Bent polished axles
6. Railride/alignment
7. Lots o’ graphite

Check the full video for the details and watch him build a car in 45 minutes – applying all of these tricks, and whipping up on the competition!