Alignment

The guide strip on a pinewood derby track will keep the cars on the track and prevent them from hitting each other. This strip is necessary but each time your car's wheels hit it the car slows down a little. This is where wheel installation become important. If the car runs straight it will less often hit the guide strip.

There are a number of little tricks to consider in this stage of the car building. First, while you must run all 4 wheels they all don't necessarily have to touch the track surface. If each wheel has rolling resistance don't roll all of them. Simple. Usually, the best one to elevate off the track is one of the front wheels. Second, to prevent additional rolling resistance install the axles at an angle to the body so that wheels ride the end of the axle not against the car body. Install your wheels so that there is clearance between the body and wheel and ensure that the car body surface has a hard finish (No washers though) next where the wheel hub might touch the body.

Test roll the car so that you are satisfied that the car rolls in a perfect line. Put the car on a flat board or other smooth surface that has a straight line scribed for reference. Lift the board so that the car begins to roll. It should roll very close to the line. If it does’t, then a front end alignment is required. Slightly bend the wheel axle(s) to correct the drift.

Checking Alignment

Another test using a long smooth surface is to check for tracking or wheel alignment. Draw a straight reference line on your surface and place the car on the surface with the wheels on top of that line. Now elevate the surface to the rear of the car to start the car rolling. Your car should roll along the that line is its tracking straight.