Forget the pencil or ruler; use our Center Of Gravity (COG) Stand to accurately measure and adjust the balance point of your pinewood derby car. The built in ruler simplifies the process of finding the exact balance point of your car.
With the wheels and axles on the car, balance the car with the rear wheels positioned over the built in ruler. Once the car is balanced on the balance beam read the measurement directly below the rear axles. This measurement is the COG of the car.
Our recommendation for the COG is as follows:
- Wood Track, no alignment consideration: 1-1/4 inches
- Wood Track, Rail-Riding: 1 inch
- Aluminum track, no alignment consideration: 7/8 inch
- Aluminum track, Rail-Riding: 3/4 inch – Better performance may be attained with a COG closer to the rear axle (5/8 inch or so). However, this reduces front wheel tracking which can result in poor performance near the finish line. So, generally a more aggressive balance point is used when a test track is available to make sure the car will perform properly.
To achieve the desired COG, ballast weight must be added behind, and in front of the rear axle. A good starting point for weight placement is 1/3 of the added weight behind the rear axle, and 2/3 of the added weight in front of the rear axle. If needed, weight can also be placed above the rear axle or across the rear axle (using an underbody weight plate).
The COG stand comes disassembled. Use a small amount of glue (super glue or epoxy) to attach the balance beam and support members.
“If you have ever tried the tedious task of using a ruler to find the COG of a car, then you will greatly appreciate the simplicity and ease of use of the COG Stand.”