How to Get the Wheels Straight on a Pinewood Derby Car
- 1). Check your Pinewood Derby wheel clearance first before making any other wheel adjustments. Wheel clearance is simply the spacing between the inside edge of the wheel and the outside edge of the wooden car body. Insert a credit card flat between the wheel and the wooden body of the car. Push the axle-wheel assembly firmly towards the center of the car until the credit card is lightly "pinched" between the wheel and the body of the car. Too much spacing, and the wheels will "protrude" from the car like elephant ears. This will cause the car to wobble from left to right on the axles. Not enough spacing and the wheels may rub occasionally against the body of the car. Adjust all four wheels using the credit-card method.
- 2). Align the front and rear axles of your derby car so that the axles are completely parallel and square with each other. With all four axles inserted into the wooden car body, and the wheels properly spaced (See step 1) place the car upside down (on its roof). Lay a ruler against each side of the car against the axle heads (part that sticks out from the center of each wheel). The ruler should have the same amount of space between its edge and the edges of the wheels (both the front and rear edge of each wheel). If you see more space between the ruler and any wheel edge, then the axles are not square with each other and should be adjusted. Do this by pressing on the side of the wheel with the biggest gap, until all gaps are exactly the same size. If your axles are not aligned properly, the car will constantly veer left or right, which forces it to contact the track center rail as it races down the track. This extra friction causes drag which slows down your car and increases your finish time.
- 3). Set the "camber" of all four wheels to zero (0) degrees. Camber is defined as the inward or outward tilt or slant of the very top of the wheel from a true vertical reference. It sounds more complex than it is---if the top of the wheel tilts towards the car body---it has negative camber. If it tilts away from the body it has positive camber. Since we want zero camber, the wheel must be completely vertical with no tilt. If camber is not zero, there is an increase in friction on the axles, causing drag (slowing you down). Adjust the camber until it is zero by placing a ruler against the side of the wheel as you look at it from the front. The gaps between the ruler and the top and bottom of the ruler should be identical in size. If not, press the side of the wheel gently that has the smallest gap with the ruler, then remeasure.
- 4). Set the "toe-in" of all four wheels to zero degrees. Toe-in is similar to camber (different axis of measurement though) and is defined as the inward or outward tilt of the front edge of the wheel from a true horizontal reference. As with camber, it sounds more complex than it is---if the front of the wheel tilts towards the car body---it has positive "toe-in." If it tilts away from the body it has negative "toe-in." Since we want zero "toe-in" the wheel must be completely parallel with the body of the car. If it's not zero, there is an increase in friction on the wheels with the track, which causes drag (slowing you down). Adjust the "toe-in" by looking at each wheel from the front of the car. You should not see any of the side of the wheel when looking at it from the front. If you do, press the side of the wheel that you see back into alignment with the rest of the wheel, so that it cannot be seen from the front of the car.