Rules & FAQ

Car Specifications:

  • Width: 2 ¾”
  • Length: 7"
  • Weight: Not over 5 Ounces
  • Width between wheels - 1 ¾”
  • Must be able to clear track: Recommended clearance: 3/8"
  • Must fit under gate: Recommended height limit: 10"

Additional Rules:

  1. Cars must remain in their own lanes. Cars may not interfere with other cars.
  2. Wheel bearings, washers, and bushings are prohibited.
  3. The car shall not ride on springs.
  4. Only official Cub Scout Grand Prix Pinewood Derby wheels and axles are permitted.
  5. Only dry lubricant is permitted.
  6. Details, such as steering wheel and driver are permissible as long as these details do not exceed the maximum length, width and weight specifications.
  7. The car must be free-wheeling, with no starting devices.
  8. Each car must pass inspection by the official inspection committee before it may compete.
  9. If, at registration, a car does not pass inspection, the owner will be informed of the reason for failure, and will be given time within the official weigh-in time period to make the adjustment.
  10. After final approval, cars will not be re-inspected unless the car is damaged in handling or in a race.
  11. Be a good sport. Play fairly. Help every Scout get a car entered into the race.

District Rules may vary. If your car goes to the District race, you will be subject to different rules.

Paraphrased Excerpt from 2016 District Rules

  1. All 4 wheels must touch track
  2. Wheels cannot be shaved to a point
  3. BSA Lathed Speed Wheels are not permitted


Do all 4 wheels need to be in contact with the surface?

No, not for our race. Yes, for district race (pending availability of their rules this year).

Ok, so could I make a car with just 3 wheels?

In theory, yes, but you should design the car so that it cannot leave the lane and interfere with another car. Running with only 3 wheels means that your car could leave its lane.

Is there a minimum weight?

No, but the heavier it is, the more potential energy there is to be converted to kinetic energy to get across the finish line. Cars that do not have weight added to them will have trouble making it to the finish line. Remember, 5 ounces is the maximum weight.

I see the rules for dimensions; why is this important?

Don’t tape stuff to the bottom of your car. It will hit the raised rail on the track.

Don’t make the car longer than the block of wood. It gives an unfair advantage.

Don’t make the car too wide. It will bump other cars.

Does my car need to be themed?

No. The theme is meant to inspire your imagination and allow creativity to be rewarded.

How much of this should my Scout do, and how much should Akela (adult mentor) do?

Firstly, this is a project for your Scout and his Akela. Secondly, it will depend on the Scout, his age, and his ability. Not every Scout will be equally able physically or temperamentally to complete the same types of work as his peers. The goal is to encourage good sportsmanship, teach a few handy skills, and have fun. If you and your Scout do this, you have already won.

Help! How do we build this thing?

There are a great many resources on the Internet that will teach you how to build one. Boys' Life Magazine published a good article on Pinewood Derby cars. Also check out Mark Rober’s “EASY Pinewood Derby Car WINS using Science!!!” video on YouTube.

Can I get an extra kit?

We have plenty of extra kits. They are $4 each. Kits are also available at the Scout Stores, and

Where can I get accessories, stickers, extra parts, paints & weights?

Most craft stores will have parts, tools, templates, weights, and jigs. A.C. Moore and Michaels both carry items, but if you need new wheels and axles, you may only use BSA official parts. The easiest place to get those is in a new kit.

The weights at craft stores are expensive (for what they are), but they are convenient. Back in the stone age when I was a kid, Dad would melt fishing weights/sinkers in a crucible and pour them into a hollowed out spot under the car. I’ve seen coins, washers, and random bits of metal taped or glued to the car. I just buy the craft store weights.

What about those special teflon coated, speed axles I see online?

No. You may only use official BSA wheels and axles.

I saw someone with red/yellow/orange/blue wheels! That’s not fair! I thought you said...

You can purchase official BSA wheels in a variety of colors from, even blue & gold (yellow) ones.

Can I thin the wheels? Round them off? Shave ‘em down?

As long as you are using official BSA wheels and axles, you can modify as you wish with one exception: the identifying logos and text must still be visible so that they are known to be official items. Significant wheel modification will likely violate District race rules, but it's ok for our Pack race.

What about the axles? Can I grind grooves on them? Can I polish them?

Yes, knock yourself out… just use official BSA axles.

My car was rejected by the official inspection committee! How can I get the car entered?

First, if you have any doubt about your car’s ability to pass inspection, you should arrive at the inspection EARLY. Bring basic tools to fix the problem on-site. Veteran racers will be happy to lend a hand and offer lots of advice. If you do this, your car will pass inspection.

I wish to appeal the official inspection committee’s decision. What can I do?

The Cubmaster has the final say in all inspection related disputes. Call me.

I can’t make it to the inspection. Can I still race?

I need to enter your car into the tournament management software prior to Saturday. If you notify me by 9:00pm on Friday night, I will enter you into the system and allow for a limited number of cars to be inspected Saturday at 9:00am. Please use this only if necessary. There’s a lot of setup and planning that goes into the race and I cannot spare much time that morning to inspect cars.

What’s the tournament format?

There are a few schools of thought on how to best run a fun and fair race. The most fair is a time-trial where each car is run once down each lane and an average time is used to rank cars. It’s also the most boring for Scouts, as they run 3 consecutive times and wait around for 2 hours. Next, people usually think of a bracket system with double or triple elimination. This is more fun, but it still leaves eliminated racers bored, requires winning racers to run more heats (resulting in more busted wheels and repair delays), scales the total race time non-linearly, and is hard to manage.

We’ve had great success in our last two years balancing fun and fair by running a point-based multi-round system where every car runs once per round with randomized opponents where the winner is awarded 3 points, 2nd place gets 2 points, and 3rd place gets 1 point. The number of rounds is predetermined based on the number of entrants and the amount of time we want the race to run. It’s reasonably fair at determining the overall fastest cars, but there is the possibility that two opponents will not face each other, giving us the possibility of ties. Each Scout gets to see their car race an equal number of times and never have to wait longer than 10 minutes or so to see their car in action.

Wait a sec, I’m concerned about fairness. Tell me more about this “reasonably fair” thing…

A few years back we wound up with two awkward results: First, we had a tie in points. These cars were separated by milliseconds in their average time. Effectively, they were tied in time too! We declared a shared victory, but popular opinion was that we should’ve run them head-to-head. This may be less fair because of the physical properties of each lane and the imperfect position of the optical sensors on the track. It’s possible that two cars whose average times are within thousandths of a second are statistically indistinguishable. If you switch lanes, the results may differ.

The second situation was that in some dens, the fastest car (by race time) was not the highest point-getter. In one case, it was a dramatic difference. The rank/age/grade winner (by points) was actually several tenths of a second slower than the next car. Those two cars faced vastly different competition. The winner had faced the Pack’s fastest two cars fewer times than the faster, losing car did. Randomly assigning heats works well to find the overall winner in the Pack, but not ranking Scouts within their rank/age/grade because it does not give an adequate number of same-group match-ups.

Hmm… I see the problem. How will you handle it this year?

Tournament Winners (Overall in Pack) will still be determined by points. If there is a tie in points, the tied racers will run 2 more races. They will be matched up against each other in Lanes 1 & 3 on the track, swapping positions for the second race. If one car wins both races, that Scout shall be declared the winner. If the cars each win one race, we will use the fastest average time from the tournament. If 3 or more cars tie, we will use the fastest average time from the tournament (no head-to-head finale).

For the "Fastest Car (by Rank)" contests, we will use only the average time. No run-off matches will be conducted to determine Den winners.