Pinewood Derby

Pinewood Derby Details

General Rules

1. All cars must be built from the official BSA Pinewood Derby Car kit.

2. Cars from previous years may NOT be used. You must build a new car for this year’s race.

3. Only one car per person may be entered.

Car Specs

1. The maximum total weight of a car cannot exceed five (5) ounces.

2. The car dimensions are: No longer than 7 inches // No wider than 2-3/4 inches // No taller than 4 inches // Minimum underbody clearance of 3/8 inch // Minimum inside wheel separation of at least 1-3/4 inches.

3. The entire car must stage behind the starting pin.

4. Weight and decorative accessories may be added to the car, but will be included as part of the car for all measurements.

5. All weight and accessories must be securely fastened to the car, and fixed in place. Wheels are the only allowable moving part on the car.

6. The car must be powered by gravity alone. Thus, weights and accessories may not actively contribute to the movement of the car.

Wheels and Axles

1. The axles must be placed in the original axle slots on the car body. The axle slots must retain the original wheel base measurement of 4-3/8 inches.

2. Only official BSA wheels and axles may be used as follows:

   • The wheels must turn about the axles and support the weight of the car

   • The axles must be directly attached to the wooden car body

   • Washers, sleeves, bushings, bearings, etc. may not be used. Nothing can be placed between the wheel and axle, and between the wheel and the car body (wheel hubs must rub against wood or painted wood).

3. No straight axles or non-BSA wheels will be allowed. Only the four “nails” and BSA lettered wheels will be allowed for these categories.  

4. Wheels may be lightly sanded and polished, but must retain the original shape (diameter, width, profile, and geometry).

5. Axle flaws may be removed and the axle shaft may be polished.

6. All four wheels must contact the ground and run flat. Raised or canted wheels are not allowed.    

7. Only dry (powdered) lubricants are permitted. All excess lubrication must be removed before inspection. Please apply lubricants outside of the building.

Pinewood Derby Tips and Tricks

A LOT has been said and written over the years on how to build the “perfect” Pinewood Derby Car. In general, the following improvements frequently come into play:

1. Shape. The car comes as a block of wood. Use a band saw, jig saw, or other parent-supervised method to shape your block of wood down. This improves aerodynamics and removes weight, which can be added back on by using …

2. Weights. All cars must weigh 5oz or less, but how you distribute that weight is up to you. The farther back you concentrate the weight, the faster your car will be at the bottom of the slope. You can purchase weights, or use your own items (pennies, etc).

3. Aerodynamics. Other than shaping your car, you can also improve its aerodynamics by sanding and painting the body. Plus, this is your Scout’s chance to really go wild!

4. Wheel resistance. There are a variety of things you can do to reduce wheel resistance, but the easiest method is simply lubricating the wheel-axle connection with dry lubricant. This can be purchased at hobby shops or home improvement store.

The most important things are to BE SAFE and HAVE FUN. And remember, it’s Cub Scouts, not Parent Scouts, so be sure your Scout is the one in the “driver’s seat” !

If you’re interested in more details, watch this video below, which describes how a NASA engineer builds his perfect car. (Remember: 3-wheels, canted axles, and lightweight wheels are not allowed)