Pinewood Derby

Sponsored by Moore Lumber & Hardware

Pinewood Derby will be held on Sunday March 9 at 2pm with Pre-check in being held on Saturday March 8 from 1-3 at the Ayer Shirley Regional Middle School

How It Works

1. Build - Each Scout starts with an official BSA Pinewood Derby Kit (supplied by the Pack). Under the supervision of an adult, the Scout will then carve, assemble, and decorate the car according to the rules and specifications outlined in the Pack 31 Pinewood Derby Rules listed below.

2. Inspect - Each race car must pass an inspection performed by members of the Pinewood Derby Committee to qualify to race. The inspection is to ensure that all rules were followed. If a car fails inspection, the racer is allowed to fix the infractions. Because of this, we recommend racers choose to have their cars inspected at the early registration event before the day of the race.

3. Race - Pinewood derby cars are "gravity-powered" vehicles. They start the race on a sloped track held back by starting pins. When the pins drop, the cars roll down the sloped track which transitions into a long flat section ending at the finish line. Each race car has 4 turns down the track. The total racing time for each racer is added up to determine the winners!

Scouts should build their race cars with speed, aerodynamics, and weight distribution in mind to ensure cars are able to gain optimal speed down the slope and keep that momentum through the flat section of the track to reach the finish line. Check out the links at the bottom of the page for more building tips!

Pack 31 Pinewood Derby Rules

OVERVIEW

Race cars must be built by the racer (with help from a supervising adult) in accordance to all rules outlined below. In addition, each car must be built for the current racing season. Purchase of pre-built cars and/or car parts as well as repeats or repaints of cars from previous years is strictly forbidden.

MATERIALS

Race Cars must be built using official BSA Pinewood Derby wheels, axles and body. One official BSA Pinewood Derby Car Kit will be provided to each scout by the Pack. Scouts may purchase additional kits or materials at the Scout Shop.

The main body of the race car must be shaped from an official BSA Pinewood Derby Wooden Block or Pinewood Derby Pre-Cut Wedge. Additional materials may be used for the use of design or weight redistribution.  All additions must be firmly attached and conform to size and weight specifications.

No part of the car’s body, wheels, or attachments can extend beyond the starting peg on the track what so ever. Additionally, the wheels may not extend beyond the rear of the car or past the front of the car.

It is recommended to add weights to the race cars to help cars go fast and make it over the finish line. 

The following items are PROHIBITED: 

• Springs

• Starting devices or propellants

• Electronic or lighting devices that interfere with the race electronics

• Liquids, wet paint, wet glue, oil, sticky substance or powders of any kind (other than the dry axle lubrication)

• Glass or excessively fragile parts

• Sharp parts that could hurt sharp objects or materials (e.g., glass) that could harm handlers or damage other cars or the track.

• Lead (Pb) or Mercury (Hg) shall not be used for adding weight, as it is a health hazard. 

• Bearings, bushings, washers, sleeves, hubcaps or inserts attached to or in contact with the axle, body or wheels

• Loose objects or objects that could become loose on the car; the car will be shaken and turned upside down during inspection

• Magnets 

SPECIFICATIONS

Weight - Race cars cannot weigh more than 5 ounces in total

Overall Width - Not to exceed 2¾ inches (including wheels and axles) 

Width Between Wheels - At least 1¾ inch clearance between the wheels to clear the center rail

Bottom Clearance Between Car and Track - No less than 3/8 inches underneath the body the entire length of the race car to clear the center rail

Length - Not to exceed 7 inches

Wheelbase (distance between front and rear axles) - Must be 4⅜ inches. It is recommended to use the precut axle grooves on the Pinewood Derby body. If new axle grooves are cut, they MUST be 4⅜ inches apart.

Front End - The front end of the car must be at least 1/2 inch wide at the center and no higher than 1 inch above the track so that the race car will rest against a short starting pin. No part of the car body, wheels or attachments may protrude in front of the starting peg.

WHEELS

Only official BSA Pinewood Derby wheels may be used.

All lettering, numbering, fluting and other BSA markings, both inside and outside of the wheels, must remain intact and visible.

The outer wheel surface may be lightly sanded, shaved or polished to remove surface imperfections, mold casting burrs and off center wheel bores. However, outer wheel surface cannot be reshaped in any way in an attempt to lighten the wheel, minimize tread contact or alter aerodynamics. Tread surface must be flat and parallel to the wheel bore.

Coning the hubs and truing the inside tread edge is allowed. Tread width may not be less than 7.5 mm. You may add material such as glue, fingernail polish or tape to the inside of the wheel, but no material may be removed from the inside surface. Wheel bore treatment is allowed including polishing and/or tapping. Wheel bores may not be filled and re-drilled to alter the bore diameter or to achieve better fit with the axle. 

The following wheel modifications are PROHIBITED: 

• Rounding of tread surface/wheel edges

• Grooving, H-cutting or V-cutting

• Narrowing the tread surface, other than truing the inside tread edge

• Drilling sidewalls

• Hollowing, sanding or otherwise removing or modifying from inside the wheel

• Filling of any wheel surface with any type of material 

• Wheels cannot be painted, no hub caps. Axles must be visible 

There must be four wheels on the car, however, it is not required that all four wheels make contact with the track surface. 

Each wheel must be mounted on an axle, on the outside of the car, in the vertical position. Each wheel must be attached directly to the wood body of the car by an approved BSA axle and spin freely. No part of the wheel may overlap the center guide rail by more than 1/8 inch. The two rear wheels and the two front wheels must be positioned directly across the body from each other. Staggered wheelbases are not allowed. 

AXLES 

BSA Nail Type axles are required with an overall diameter of no less than .084 inches for each wheel. Some polishing and/or modification (bending) is allowed as long as the overall diameter is not reduced below the .084 requirement. Grooving of the axles is prohibited. Axles must not be connected to any device that mechanically alters rotation or spin. Wheel bearings, washers, or bushings are prohibited. Axles must be mounted in the wood sections of the car using the pre-cut axle grooves or grooves that keep the wheel base the original distance of 4⅜ inches apart. Solid axles across the car are not allowed.

LUBRICANTS

Only dry powdered lubricants, such as graphite, may be used. Wet or oil lubricants of any kind are not permitted. Race cars must be lubricated before inspection (during preregistration or race day registration). After passing inspection, only members of the Pinewood Derby Committee can handle the race car until after the race is completed.

INSPECTION

To qualify for the Pinewood Derby Race, each race car must be registered and pass an inspection in accordance to the Pack 31 Pinewood Derby Rules. If a car does not pass inspection, the racer can make adjustments to fix the infraction(s). After passing inspection, only members of the Pinewood Derby Committee can handle the race car until after the race is completed.

Building Tips

Check out these links for helpful tips for building a Pinewood Derby Car! WARNING: these pages may suggest modifications that are against our rules (e.g. reshaping wheels, extending the wheelbase, grooving axles)! Be sure to check the pack rules before making any modifications to your race car!

• Use Science to Build the Fastest Pinewood Derby Car- https://boyslife.org/hobbies-projects/projects/138909/use-science-to-make-a-fast-pinewood-derby-car/

• How to Make a Fast Pinewood Derby Car - https://boyslife.org/hobbies-projects/projects/2952/speed-secrets/

• Frequently Asked Questions About the Pinewood Derby - https://boyslife.org/hobbies-projects/pinewood-derby/162603/pinewood-derby-questions/

2023 Quinapoxet District Pinewood Derby Rules: https://hnebsa.org/wp-content/uploads/2023/01/2023-Quinapoxet-Derby_Rules.pdf