Pack 421’s Pinewood Derby Rules

Last revision: December 17, 2023

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GENERAL

• The car must be built for the current Pinewood Derby Racing Season. No repeats or repaints.

• Complete cars purchased from a third party are not allowed.

• The car may not be sent to a third party facility for tuning or other performance enhancements.

• Each car must be given a name at check-in. Car names can be multiple words but should not exceed 20 characters including spaces. Longer names will be allowed but could be truncated on race displays.

body

• The car must be freewheeling.

• The main body (chassis) must be made of wood.

• The car design may be enhanced by the addition of other stable materials such as plastic or metal. Any additions must be firmly attached and meet car size specifications.

• The car must meet the following specifications:

  • Width (including wheels): not to exceed 2.75 inches

  • Length (including wheels): not to exceed 7.00 inches

  • Height: not to exceed 3 inches (heights above 3 inches may be allowed as long as the car will fit under the finish gate)

  • Weight: not to exceed 5.0 ounces on a scale accurate to 1/10 ounce

    IMPORTANT: Car length, width, and weight are strictly enforced. Weight is strictly enforced to 1/10th ounce accuracy. It is advantageous to make the total weight as close to 5.0 ounces as possible without going over. If a car exceeds 5.04 ounces at inspection, the scout will be asked to remove excess weight (using a drill or file if necessary) until the weight is at or below the limit.

    Note: Most kitchen scales are not accurate enough to measure a Pinewood derby car properly. Postal scales are more likely to have the required accuracy. At the race, the official weight of all cars will be determined by inspectors upon check-in using a single, high-accuracy scale to ensure consistency. Be prepared to make adjustments if needed.

• Weights: Most cars have metal weights added to bring their total weight up to 5.0 ounces. The use of lead weights is strongly discouraged. Zinc, tungsten, brass, or other safe materials are recommended instead. If lead is used, it should be completely sealed and not exposed where it could be contacted by children or race officials. Drilling, cutting, or filing of lead (to reduce excess weight) will not be permitted at the race venue due to safety reasons.

  If coins or other loose items are used to add weight, make sure they are securely attached (use strong glue, not tape!), and take special care if placing them on the bottom to avoid creating obstructions (see the Clearance and Undercarriage sections below).

• Clearance: Cars roll down the track on a center guiderail that is 1-5/8 inches wide and 1/4 inch tall. The undercarriage of the car should therefore have a clearance of no less than 3/8 inch. However, if the car can rolls on the track without touching the guiderail, the clearance will be considered legal. The wheels are the only part of the car allowed to touch the track. Note: If questions arise about a car’s clearance during check in, race inspectors should place the car on the track to verify that only the wheels touch the track.

• Undercarriage: The bottom of the car’s body should leave a clear path for the guiderail and avoid having protrusions or edges that might catch on the track’s guiderail or braking pads. (When the car reaches the end of the track, it will slide on rubber pads for braking.) If there are deep notches or sharp protrusions on the bottom of the car, they could catch and cause the car to bounce up and off of the track, possibly injuring itself and/or other cars.

• Fenders: Fenders and other body parts may extend below the undercarriage of the car at the sides as long as they do not rub or pinch the track’s guiderail. Fenders may not cause the car to exceed the allowed overall dimensions.

• Wheelbase: Axles may be installed in the precut axle slots that come in the wooden block from the BSA Pinewood Derby kit, or you may drill new axle holes for a longer wheelbase. A longer wheel base promotes a more stable car path and makes the car less prone to breakage.

  IMPORTANT: Make sure no part of the front wheels protrudes ahead of the leading edge of the car body (see Front Edge of Car below).

• Front Edge of Car: At the starting gate of the track, the front edge of the car will rest on a retractable starting pin that protrudes upward from the center of the track. No part of the car (including the front wheels) may extend forward of the starting pin.

  The front edge of the car should be at least 1⁄2 inch wide at the center of the car. This recommendation ensures the car rests securely against the starting pin when placed in the starting position and is wide enough to trigger the electronic timer. A needle nose car will be permitted to race, however its performance will suffer because the nose will not trigger the electronic timer accurately. If you choose to run a needle nose car, the electronic time, even if it is slower than the car’s actual time, will be the official time.

• Glitter and Powders: Glitter and powders of any kind (other than axle lubrication) may be used only if securely adhered to the body of the car and must not shed. Such substances if deposited on the track can be pulled into wheels of other cars and affect performance.

• Electronic Components: Decorative lights and electronic components are permitted if they do not interfere with race electronics and do not provide any propulsion or performance advantage. You will not have an opportunity to turn electronics on or off after car check-in; therefore, make sure the battery is on prior to check-in and can last through the end of the race. Electronic devices that make sound should be silent during the race.

• The following items are prohibited:

  • Springs

  • Magnets

  • Starting devices or propellants

  • Bearings, bushings, or washers on wheels or axles

  • Wet paint, liquids, oil, or sticky substances

  • Glass or excessively fragile parts

  • Loose objects

Wheels

• Only “OFFICIAL BSA” wheels are allowed. The wheels included in the official BSA Pinewood Derby kit are black, but official BSA wheels in other colors are available for purchase from the Scout Shop and may be used instead.

  IMPORTANT: Legal wheels have the lettering “OFFICIAL BSA” embossed in the plastic. Wheels sold at Hobby Lobby and other hobby shops under brand names such as PineCar, Pine Pro, and Revell claim to be authorized by the BSA and/or compatible with BSA rules, but they are not official BSA wheels and will not be permitted to race due to differences in performance characteristics.

• All lettering and numbering on the outside and inside of the wheel must remain complete, unaltered, and visible for inspection.

• Each car must have at least 3 active, free-spinning wheels in contact with the track and attached to the sides of the car body using a legal axle. In the place of a typical 4th active wheel, the car can have a slightly raised (inactive) wheel, guide fin, or similar contrivance. The wheels (and fin if present) should be positioned with sufficiently distributed wheelbase to ensure the car engages properly with the guiderail on the track to prevent the car from leaving its lane during racing. If there is any doubt about this during check-in, the race officials should test the car on the track and, if necessary, require modifications.

• The tread surface (flat part of the wheel that touches the track) may be sanded, shaved, or polished to remove imperfections and to true roundness, but the tread surface must remain flat and parallel to the wheel bore. Rounding, grooving, H-cutting, or V-cutting of the tread surface is prohibited. Do not remove too much tread material; the decorative spokes and fluting (small dots on the sidewall of the wheel) must remain visible and complete around the entire circumference of the wheel.

• The edge of the wheel tread facing the car body may be lightly worked so that it is made smooth and straight, but the width of the tread surface must not be reduced to less than 6.5mm. This rule is in place to prevent extreme narrowing of the tread in an attempt to reduce weight. Tread width will not be measured unless a wheel appears to be noticeably and significantly narrowed.

• Lathing, sanding, or removing material from the inside of the wheel is strictly prohibited. Wheels will be checked for this during check-in. Violations can easily be detected due to having thinner than normal plastic thickness, missing lettering, or non-standard machine marks (grooves) on the inner surfaces. Cars with illegally modified wheels will not be allowed to race in the Pack Championship Series or Open division, but may be entered in the Outlaw division.

• Drilling of holes or making cavities in the wheel (tread, sidewall, or bore) is prohibited.

• Truing or coning the tip of the inner hub of the wheel (which touches the car body) is permitted. Removing the step on the outer hub of the wheel (under the axle nail head) is also permitted.

• Wheel bore treatments, including polishing, waxing, sanding, and/or tapping are allowed. However, filling and re-drilling the wheel bore—or narrowing the wheel bore in any other way (e.g., bushings, bearings, etc.)—is prohibited.

• The inside cavity of the wheel may not be filled with any material except small amounts of fingernail polish for rotational balancing.

• Washers, air shields, and air dams between the wheel and car body or between the wheel and axle nail head are prohibited.

• Accent paint, stickers, and decals on wheels is not recommended but may be permitted if the race officials determine that it provides no performance advantage and is not likely to shed or fall off during the race.

• There will not be an opportunity to adjust wheel alignment during the race. Make sure all wheels are properly aligned and adjusted prior to check-in.

Pack Championship Series 🏁

The Pack Championship Series shall be organized in two rounds: a Qualifying Round with all Scouts in divisions by den, followed by a Grand Final.