What do your Pinewood Derby Rules Mean?

In my ten years of Pinewood Derby experience, these questions have come up a lot.  I would like to help answer any questions you may have about your rules to the best of my ability.  Please don’t hold us responsible and if more clarification is needed please refer back to your den leader.  This is just a resource to help you understand what your rules mean.  Most rules are very generic and are open to interpretation.  Many packs address certain parts of the generic rules specifically in order to make things fair.  We will do our best to give an unbiased opinion of what your rules mean.

Below is a list of common rules for pinewood derby.  These rules may differ, so be sure to read the rules for your race.

  1. The car weight shall not exceed 5 ounces.
  2. The overall length of the car shall not exceed 7 inches.
  3. The overall width of the car shall not exceed 2 ¾ inches.
  4. The car must have 1 ¾” clearance between the wheels.
  5. The car must have 3/8” clearance underneath the body.
  6. You must use the wood that is provided in the kit.  The block may be shaped any way that is desired as long as it meets the length and width requirements stated above.
  7. The wheels supplied with the kit must be used. The wheels may not be cut, drilled, beveled or rounded. You may remove the seam from the wheels.
  8. The axles supplied with the kit must be used. They may be polished or lubricated.
  9. Wheel bearings, washers or bushings are prohibited.
  10. The car must not ride on any type of springs.
  11. The car must be freewheeling, with no starting devices.
  12. No loose material of any kind, such as lead shot, may be used.

Pinewood Derby Rule #1

The car weight should not exceed 5 ounces.  This is a pretty straight forward rule.  The weight is based on the scale provided for at the race.  You should bring extra weight (such as tungsten putty) at the weigh in so if your car is underweight you can add the weight as needed to make it as close to 5 ounces as possible.   If you are overweight, you can drill a few small holes on the bottom towards the back, bring some tape with you to cover up those holes.  Make those fine adjustments at check in to get the best possible potential energy for racing.  The closer to 5 ounces the better potential energy and the faster the car.

Pinewood Derby Rules #2-6

Now to go over dimensions.  Your car should not exceed 7 inches in length.  That includes any toys or fixtures you may want to add onto the car for decoration.  So when designing the car make sure you take that into account before cutting your block of wood.  But it CAN be SMALLER than 7″.  There is no speed disadvantage to this measurement.

The car should not be wider than 2 3/4 inches.  The block you receive is 1 3/4″ thick.  So this rule pertains to those of you who plan to decorate with fenders or whatever else you can think of.   At the same time, the wheels should be at least 1 3/4 inches apart.  To measure this, flip your car upside down.  Measure the distance between the front two wheels from inner most part of the wheel to inner most part of the opposite wheel.  Repeat for the back side.   This is especially important for those that have learned that wheels that are closer together get a better ride.  The easiest way to make use that you fit within these dimensions is to make sure that a standard block will fit between the wheels once your car is completed, no ruler necessary.

And the last part of the dimension rule is that there must be 3/8 inch clearance from the bottom most part of the car body and the track.  Most of the time this comes into play if you have those bottom lead plates that screw or glue on the bottom of the car.  So if you are using that type of weight, it might be best to make sure to measure this distance prior to race day.  If you drilled your own axle holes, be sure to check this as well.    The placement of your wheels could be too high on the block.

Pinewood Derby Rule #7  (The gray area begins)

You must use the wheels that come in your kit.  There are 16 different mold numbers and every single mold and wheel can vary.  A good set of wheels is the utmost important for speed.  Lighter wheels are faster.  Round, true wheels are faster.  The lighter the wheel the less rotational inertia and the faster your car can move.  In order to do these modifications correctly they require specialized tooling.  If you are interested in this type of upgrade, please visit our online store.

There are always several questions on the wheels.  Please double check your rules on the wheels as these do vary from pack to pack.  Most packs say the wheels cannot be cut, drilled, rounded, or beveled.  But you can remove the seams.  Removing the seams means you can remove the outer layer of the wheel in order to make the surface that the wheel runs even and true.  This can be done with sanding or using a lathe (lathe work is not always approved in the rules so please double check).  You also need to make sure there are no rules that indicate a specific diameter for the wheels.  This will determine how much of the outer wheel hub you can remove.

Another rules states that material may not be removed to drastically change the weight of the wheel.  If this rule applies to you, you can not use a wheel that has been machined to be lighter. So you probably are in the 2.6-2.45 g wheel weight range.

If you rule states that all lettering must be in tact, but does not address the rule about weight reduction, then you can use use a weight reduced wheel.  Be sure to check each wheel to make sure it has lettering.  Some wheels do not have lettering.

Pinewood Derby Rule #8

Second most commonly asked questions are related to axles.  You must use the axles included in the kit.  Please double check your rules on axles as well.  You can usually polish or lubricate axles with a dry lubricant, but usually not with an oil lubricant.  Some rules allow for bent axles and some do not, same thing with grooved axles. There is so much detail involved in axles that I would recommend you check out this article for answers to any of your questions or you can read the other pages on this website related to axles.

Items you cannot use in a pinewood derby car include wheel washers, bearings, and springs.  The car must be able to start on it’s own by using gravity.  No engines or electrical device.  And everything on the car must be solid on the car.  No loose material.  A good rule to abide by is if it doesn’t come in the pinewood derby kit you probably can’t use it, unless it’s a decoration.

If you have any questions about your rules, please email us a copy of your rules and your question.  We would be happy to help.  Please email tech@derbydust.com for your technical questions.