This year’s Pinewood Derby will take place at Park School.
The “Parents’ Night” set-up event will occur on Friday early evening, March 3rd, and includes parents from all three Mill Valley Cub Scout Packs (1, 33, and 34). Impounding of cars will be facilitated late that week as well.
The actual race is on Saturday, March 4th. Our Pack’s time slot is 2:00PM.
More information will be provided via email so stay tuned…
The Pinewood Derby is a long-time traditional Cub Scout activity. Cars should be designed and built by the Scouts as much as possible. It is expected parents will participate handling power tools where necessary, etc., but it is the spirit of the event that the cars are inspired by and built by the Scouts. The parent involvement will be greatest with the Tigers and should progressively decline as the Scouts move into Bears and Webelos.
The Derby events are divided into 2 days. Cars will be checked for rules compliance, once they qualify, will be impounded until the racing is completed. Scouts should lubricate (dry lubricant only) and completely prepare the car for racing before submitting it for inspection. Cars that fail initial inspection can be repaired to conform, but cars MUST be qualified before race day – there is NO Race Day inspection or qualifying.
These rules may seem overly specific, but are meant to ensure that the cars will all run on the unique Pinewood track, that the competition is fair for all participants and that winning Pack 34 cars will conform to the rules of the Marin Council Meet at the County Fair. There are many books and websites out there on derby car design and many of the tips in those books do NOT conform to these rules.
If you simply use the kit, shape the block, add weight, paint, and push in the provided axles and wheels there is little to worry about in terms of construction rules. Here are the high points:
- NO CAR RECYCLING: The car must have been made for this year’s race.
- NO PREBUILT CARS: The whole point it to build it. You can buy prebuilt cas on the internet. Please do not.
- WEIGHT: Must not exceed 5.0 ounces on a scale accurate to 1/10th of an ounce.
- Width – Width between the wheels not to exceed 2 ¾ inches
- Length – Not to exceed 7 inches
- Height – Not to exceed 4 inches
- Center Rail Width: Must clear center guide rails, typically no less than 1-3/4 inches minimum.
- Bottom: No less than 3/8 inches from track surface between center rails.
- BODY DESIGN: Front of car must be a minimum of ½” wide, centered, and no more that 1” off the track because the start system of the track consists of the cars resting on a slope against a pin. No part of the car can extend past the starting pin.
If you choose to push the boundaries, and try to get “creative” please be aware of the following:
- MATERIALS: Only the official BSA kit blocks, wheels, and axles may be used. One complete kit will be provided at a pack meeting in February. Replacement kits and wheels can be purchased at the Trading Post in San Rafael. Again, only official BSA kits / parts may be used. Please, do not purchase prebuilt or pre-cut cars or “after market” parts such as wheels or axles.
- AXLES: Pre-cut axle slots MUST be used and not modified in any way. Only official BSA Nail type axles may be used.
- Use only Official BSA wheels. All lettering/numbering, both inside and outside, must remain complete and be visible. The fluting and other BSA markings on the outside wheel area must remain visible. Outer wheel surface may be lightly sanded, shaved, or polished to remove surface imperfections and mold casting burrs, but must not 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.
- No bearings of any kind may be used
- Wheels cannot be painted, lacquered or modified in any way
- Wheels cannot extend beyond either the front or back of the car body
- All four wheels must be in contact with the flat surface when rolled on a flat surface
- The following wheel modifications are PROHIBITED:
- Rounding of tread surface/wheel edges
- Grooving, H-cutting or V-cutting
- Altering of wheel profile
- Narrowing the tread surface, other than truing inside tread edge
- Drilling sidewalls
- Hollowing, sanding, or otherwise removing or modifying material from inside the wheel
- Filling of any wheel surface with any type of material
- “After Market” wheels are usually lightened in a way that violates these rules.
- PROHIBITED ITEMS:
- Starting devices or propellants
- Electronic or lighting devices that interfere with the race electronics.
- Liquids, wet paint, oil, sticky substance, or powders of any kind (other than axle lubrication)
- Glass or excessively fragile parts
- Bearings, bushings, washers, sleeves, hubcaps or inserts attached to or in contact with the axle, body or wheels.
- Loose objects on car
Racing is done by Den in the following order: Tigers, Wolves, Bears, Webelos 1, Webelos 2, with one winner out of each age group. This will be followed by an open race targeted primarily at siblings (think little baby brothers, big kids, and Gummy Bears). Open race cars must still conform to all of the above rules and be checked in accordingly. Each car races four heats – one on each of the four lanes of the track. Of the four heats, the worst time is dropped and the winner is the car with the fastest average time for its three best heats, measured in elapsed seconds. The five Den winners qualify to race in the Marin Council Meet, which annually is held on the first day of the Marin County Fair. The five Den Winners will be impounded at the close of our races, in accordance with Marin Council rules, in order to qualify to run at the Council Meet.
Funny, unique designs are encouraged. There will be special design prizes awarded irrespective of car performance. Cars can be accessorized with almost any kind of item provided the completed car meets all the rules, which are listed above.
- The more the scout does on the car themselves the more they will love it. Let them do the work, guide them, and keep them from cutting off their fingers. Other than that, hands off!
- The car can be 5oz and no more. Generally the closer to 5oz that a car is the better it will perform. 4.9 is great. 3 may not make it to the end of the track. If you do not have a scale you can hop over to the post office. Coins make great weights in a pinch.
- There are hundreds of PWD secrets out there. Many of them go against the rues and will result in your scout’s car being disqualified. If your scout wants to push the boundaries please review the full rules on the PWD page. For example, three wheeled cars, extended wheel bases, shaved wheels, will all cause a car to be DQ’d.
- Lubricare the axles with graphite.
- The best cars will weight 5oz, have lubricated/polished axels, and go straight. When in doubt, keep it simple.