Use Science to Build the Fastest Pinewood Derby Car
For seven years, I worked at NASA on the Mars Curiosity rover. It is just like a Pinewood Derby car, except it has six wheels, it’s nuclear powered and it shoots lasers.
My Cub Scout son and I decided we would take the science principles I used while building stuff at NASA and apply them to making his Pinewood Derby car.
Take a look at some of those science principles in this video and check out my list of the most important steps for making fastest Pinewood Derby car possible.
SEVEN STEPS FOR MAKING THE FASTEST PINEWOOD DERBY CAR
1. Max out your Pinewood Derby car’s weight at 5 ounces
Get as close as possible to the car’s maximum weight (usually 5 ounces) and make sure the heaviest part is about 1 inch in front of the rear axle. This is the most important step. Science shows if you do this correctly, you will beat a Pinewood Derby car built exactly the same — except with the weight toward its front — by 4.6 car lengths. It works because the farther back the weight is, the more potential energy you have because your center of mass is higher up on the track. (Don’t put it too far back, or your Pinewood Derby car will become unstable and pop a wheelie.)
2. Use lightweight wheels.
Using non-standard wheels is illegal in some packs’ races, but if it’s not in yours, this is a must-do step that will give you a 2.1-car-length advantage at the finish line versus a car with normal wheels. It works because heavy wheels take away from the kinetic energy (the energy something has due to its motion), which makes the Pinewood Derby car slower.
3. Use bent polished axles.
Bending your Pinewood Derby car axles with a bending tool will make the wheels ride up against the nailhead, which creates less friction than if the wheel is bouncing around and rubbing against the wooden Pinewood Derby car body. See video above for details.
4. Railride.
Railriding means you steer your Pinewood Derby car into the center guide track just enough that you keep the car from bouncing around. This helps reduce friction and saves energy for speed. See video for details.
5. Create a Pinewood Derby car that is reasonably aerodynamic
An aerodynamic Pinewood Derby car’s design cuts down on drag caused by air. No need to get crazy here, but simply having a wedge-shaped Pinewood Derby car instead of the standard block out of the box will equal a 1.4-car advantage at the finish line.
6. Ride on three wheels by raising one wheel off the track.
You will move faster if you have to get only three wheels rotating, giving you a 1.1-car advantage over an identical Pinewood Derby car riding on four wheels. (Check your pack’s Pinewood Derby rules to make sure this is allowed in your race.)
7. Use lots of graphite.
Graphite is the best way to lubricate your wheels and axles. There isn’t a big difference in types of graphite, so buy the cheap stuff and use as much as possible. Be sure to get plenty around each wheel and on the axle.
THE WINNING CONCLUSION!
It works! After my research, my son and I wanted to do one final test to prove that this is a good list. So we built a simple Pinewood Derby car using this list in 45 minutes, and we beat the fastest Pinewood Derby car in our local race by two car lengths. Turns out, science works!
Mark Rober worked as a mechanical engineer at NASA for nine years. During this time, he worked on Curiosity, a car-sized robot that left Earth in 2011 and landed on Mars in 2012. Mark is well-known for his YouTube videos on science, engineering and gadgets.
Your thoughts on aerodynamics is completely backward.
A wedge is slow, a teardrop is fast.
Thanks it really helped me allot
Thanks! this is so helpful!
Nice
SWEET THE RACE IS MINE
awsome sauce!
i think that i will use this tech on my car i got third place last year, (nowhere to go but up!)
I will probably use this in my pine wood car
LOVE MARCK ROBER!
I like how they used Mark Rober’s science
Mark Rober videos are the best.
Fun way to learn science.
Waooo this is really something
All of these points are correct. If you can test right vs left rail riding do so. My son set a new track record, but came in second overall by .0006 second.
Make sure you check your councils rules. Our council would disqualify for a few of these
If riding on only three wheels, why not eliminate the fourth wheel altogether ?
Should the car also be as low as possible to minimize the air flowing under it ?
Thanks – Peter D.
That fourth wheel still must be in place to guide the car. It might not touch the floor of the track but it still is needed to follow the center guide rail.
love it, thanks!
thanks
Or amazon it
who is subbed to this wizard?
disqualified using polished axles….. said it right on the BOA pinewood derby sheet!
Other than putting the weights in the back, does it matter if they sit on top of the car or should they be under the car? Does changing the center of mass affect the performance? I’m considering flipping the car upside down so the axles are on top, and then inserting the weights underneath (or recessing them). The idea is that the car will ride lower overall and will help to reduce drag.
thank you <3
I love this the science is quick and easy and ours was a drag race car and my son loved it
This is usful
Love it
So Do we want 3 of the wheels bent or just the back 2?
used these tips at a work pinewood derby race and came in 2nd out of about 60 cars. Seems to work well.
This video was really good my son won second place
ThIs Is ReAlLy GrEaT ThAnK YoU
That is an awesome video thank you for all of the good pointers.
Just entered a car in our work pine derby tournament that had 50 entries. I used the advice in this article to build my car and we won first place beating out all of the other 50 cars!
Our first year in Cub Scouts (my grandson was a Tiger) and he designed and did a little of the work in each section (sanding, painting, etc) and his car won 3 trophies. It didn’t follow any of the suggestions in the video, other than the graphite. Others at the meet were experienced PWD parents, and we still beat them….there is some luck involved. I do like the science of the video.
I like the article. I enjoyed reading the science.
Some rules vary from pack to pack, maybe that’s why it says you can’t
With all the finessing of the cars, has anyone thought to add magnets, small motor…etc. I mean, speed tricks should be about polishing the axles, weight, aerodynamics, and de-burring the wheels. Everything else gives an unfair advantage to kids whose parents aren’t able or don’t help their scout. When your bent axle, three wheeled car wins the race, you should be really proud.
Science wins the day. Wedge with weight placement mentioned above and graphite allowed my daughter to win her Derby. Thanks
If it’s the BSA Pinewood Derby, why would there be different/separate rules by district?
Our Pack leader sent the video to everyone. No mention of any issues with the rules. This is our First year so we followed the video almost 100%. We will see how we fair next weekend. If everyone does it then it should be very interesting.
Funny how important pinewood Derby car ravaging is. Love that the video includes stem- the science and physics behind the scenes that gives a competitive edge. What a great way to include science and make it fun.
After 17 years of building pinewood derby cars, I find this is a complete list of speed secrets. If a mom can accidentally drive a nail into a pinewood derby block at an angle then you cannot outlaw rail riding, 3 wheel, or angled axles. The only secret to add is put your car on a treadmill for many hours adding graphite every 20 minutes.
Let cubs truly build their own cars and be proud of what they did, regardless of 1st place or last. Let the dads or moms do as much as they want but on their own cars in SEPARATE PARENTS’s division.
We built an alignment jig, still have it. Which would allow us to set the wheels at the optimum angle, so the car would run on the edges of the wheel. When we went to the derby the we always set the car and carried the car on the jig. only time it came off was when it was ran.The axle and wheel polishing probably did the most in gaining speed. My oldest son did the best job of polish and prepping the wheels and axles.
This is a educational event.. if you’re telling the kid to do whatever that defeats the whole purpose. They should be researching and learning the science that’s involved. Other wise its simply play time.
As a winner of 3 in a row, my son’s simple wedges proved aerodynamics don’t mean much. There were other cars more aerodynamically designed. They aren’t going fast enough to matter on aero. Polishing the AXLES (with a lot of graphite) is the secret. Be sure to polish down the underside of the head of the nail — assuming your rules require using the standard nails that come with the block kit.
Move the center of gravity as far back as possible.
While I appreciate the link between science and Derby success, unless these techniques are readily achievable by the average 6-10 year old, it seems more about the parent need to win than the Scout’s involvement and enjoyment.
Rail running is illegal??? Man where is that at?? Graphite is messy, gets all over nice paint jobs, track, and possibly harmful if breathed uhhgg thank God for Krytox for lube. Finally got our District on board for allowing its use since its sold in the scout shops around here. Hollow out bottom of a 3/8 inch car body and use tungsten cubes foe weight is way to go.
Almost everything is illegal. There should be bigger disclaimers, especially for new parents!
Somehow, this just does not go with my idea of a Cub Scout built race car. Sounds like Dad did most of the work!
Remember there are more ways to win besides just being first. My sons tended to focus on design and often were awarded ribbons for “coolest car” etc. The best part for me was the shared experience of manufacturing the car.
I did all this spent over 100 dollars on the car. It still failed
Rules I read say canted axles are allowed.
There is no way this cost $100. We used graphite $5, weights $5, stickers, $2, paint at the house and a saw. Put weight 1 inch in front of rear axle and that was it. My daughter won every race.
I love the comments about knowing “other ways to win” – maybe instead of using science, magic is used instead?
Oof
My son won first place overall—twice!—using these tips. It redeemed me as a self-sufficient Navy mom after my older son tied for last place in his first derby. (I know, why would they even keep track?)
Some of this stuff is illegal in my pack
Most of it is illegal in our District, hence, our Pack, which follows District rules to flow through without rules incidents at the District race.
This video is great!!! My son and I used his formula and won 3rd overall and 1st at sectionals for tigers. This year we are looking to make it even better. Dads need to watch and follow.
super helpful
no… just no
hi
hopefully this works.
it does not work
I think it was good and i will try to follow his ideas!
That was really helpful!
I’m using your site for a project for an engineering class. Your site is the best site by far for my project. Thank you!
Too bad all of the advice except weight placement makes the car illegal in any organized races.
Reasonably aerodynamic is illegal in your race… wow tough rules.
Only light wheels is illegal for the Northstar council everything else is ok.
Used the tips in this video and others by this guy to help my son build our first ever car and destroyed the other cars. Finished first in every heat.
Great tips Mr Rober!
It doesn’t work. I did all of these tips and got destroyed by crappy store bought cars. I really trusted the science but it let me down
Is it possible you did something wrong. I used everything and we did great
It is store bought cars NOT Cub made…that is the difference….. family fun is 90 percent Winning with store bought cars is missing the whole purpose of scouting….just feel sorry for them, they will miss half of our purpose on University Earth Life
Mark Rober (the guy who is behind this) made the worlds largest nerf gun and it is on youtube
you cant railride
i tried this and i won
my race requires a 4-wheeler!!!!
this is amazing
Even if it does you still have four wheels ones just not on the track
I’d like to see the evidence that a wedge shape car can give you anywhere near the lead claimed in this article. The test results I’ve seen in other scientific tests have pointed to aerodynamics being of relatively low importance in these races.
My son and I watched the video at built our cars (we had a parent’s divison too) and both won first place. Proud of him for understanding how to apply the knowledge he gained from Mr. Rober’s video. Proud to watch him succeed with his own work.
My son watched the video and really understood the physics. He took the time and balanced the weight and aligned the wheels as in the video. He won(earned) 1st placed in his Pack with the work he put into his car.
Hey I’m just a 9 year old boy and this video is really helpful
Loved the article. After three sons with lots of top 5 finishes but no first place, my youngest son just won our derby today. Our first step before we did any work in the garage was watching this video. You finally convinced me to try the three wheel design. We should have done this eight cars ago.
Awesome!
I am so gonna win pinewood derby… or at least a gold medal with this awesome video. Thanks, Mark!
Rail riding is probably illegal.
Wedge is probably the best easy design.
That video is going to help me and my brother win this!
I like trains.
Wow!
This advice is good, very similar to what my son and I did with his cars, and we had very fast cars. I taught my son to drill the rear axle holes at a slight angle (after filling the slots with putty). This way you don’t contort the axle after getting it all polished and shiny!
Rail riding is difficult if you are not allowed to raise a wheel, but you can still steer the car mildly into the rail with the front wheels. Keep the back wheels off the rail (this can be done by slightly indenting the front wheels. Also, rather than bend the nail, I like to drill a guide hole for the rear wheels that is just slightly angled (I fill in the slots with putty). Same effect, but less chance of messing up your nicely polished axles.
I think the video was very helpful
yeah.
Rail riding will get you kicked!
Use regular unbent axles
Girl Scouts are doing this now 😂😂😂
HORRIBLE! GOT DISQUALIFIED!
On one of the pinewood derbies I had gone to, a boy had tried out the wedged block trick. What I also heard about what he did was obvious, he maxed out the cars weight, but before, he had baked the block in the oven for a half hour on 350 degrees, making this as light as a feather. Shortly after that, he had taken out parts of the block so that he could replace it with weights, this being on the center balance point of the vehicle. The last major adaptation to his winning car was all of the graphite that he applied to his cantered wheels. For years afterward, he won the derby, making him someone to follow after.
Cool tips will use this at derby! !!
#7 couldn’t be more wrong. Go ahead and use the cheap stuff and overpack it if you want to lose vs someone who uses good stuff correctly.
Also the axles (nails) have a raised edge under the nail head from the manufacturing. Chuck the axle nail in a dremel tool and use a jewelers file or even sandpaper to remove it while the axle is spinning, like a lathe (clamp the dremel to a work bench to make it easier). Then polish that section of the axle. But don’t take off too much metal!
epic!!!
A wedge with little grooves in it works better than just a wedge. Tried it. I quit a while ago so I don’t care if anyone tries this trick.
i’m doing a science fair project, and so far this has worked
I personoly wouldent do the three weeler thing.
P.S. the cars go to slowly to make airodenamicks
matter.
Aerodynamics always matters…
Some of these sound questionable.
3 wheels touching the track creates less friction than 4 wheels. It works.
Wrong… friction per wheel increases so the net friction is the same. What makes 3 wheels faster is less rotational inertia. There is one less wheel that has to accelerate (radially). This means faster acceleration.
If I only knew all this in 1978, I would have placed first instead of second! 😉
I gonna try this at the pinewood derby.
Is it true
Best info ever
fast
ill try this
that’s nice
cool
next derby im gunna domanate if i try this ……im exciteded
Good Ideas for This Month!!!
love it
cool
do you need the special tool to bend the axles?
Can you send a picture of the car
yeah if you want to do it right
District competition rules may be stiffer than the Pack rules.
Parent and sibling races may have looser rules since they don’t move on to District.
This is a great video for explaining the principle’s of why all cars don’t run the same.
It may be better at explaining that to some overly competitive parents than to the Cubs.
ALWAYS make sure the Cub has a good time building it…fast or not in the end.
awesome
Soooooo gonna try yhis😁
Interesting!!
polishing wheel bore is as critical as polishing the axle, without it friction reduction is marginal..
This will help alot!
Our Pack provides awards for 1st place, fastest looking and best craftsmanship. We build ours for show. We stand a better chance and the second two! LOL! I have never been able to master the axles.
Sounds like less friction is the key!!!
Awsome!
COOL!
How should the wheels be slanted if all four have to touch the ground? That is one of our rules.
Our rules state all 4 wheels must touch the ground at the same time. So what is the best way to slant the wheels?
does it work?
Yes!!!
Nicely done and relevant video to incorporate with STEM requirements. Many thanks!
Riding on three wheels is not allowed in our race. So would that mean that both front wheels should be situated to make the car run into the center track?
Cool
Awesomely way cool
Cool
This stuff is awesome thinking of doing it myself
This has become the new go to video for teaching kids about the physics of pwd. The only thing he really got wrong was the axle bending. The adult pro racers do not bend their rear axles, they drill the rear holes at an angle to canter the wheels. The only axle they bend is the front dominant wheel to adjust steer for rail running. Scouts will most likely also have a hard time to properly get their rear wheels aligned using bent rear axles.
Most of his tips arent tricks and most are legal. Yes the lightened wheels and aftermarket axles are illegal in most scout rules. The other stuff only a few may have extra rules to keep from canting the wheels or only riding on 3 wheels.
Only thing he really got wrong was saying the fastest derby pro racers use bent axles. They drill their rear axle holes at a canted angle. The only axle that is bent is the dominant wheel to adjust the steer. Most scouts will likely not be able to get their rear alignment straight using bent axles either.
physics and science is a good way to win
love it
Honestly, some of these tricks are illegal according to our rules. There is other tricks but I am not saying what they are. And there is books on the subject at your council office. 🙂
You need to explain the rules to the boys and explain why the rules are there.
I would like to thank Mr. Rober for sharing his speed tips and expaining the science behind each one. Very interesting!
More importantly, I would like to thank him for pointing out which tips may be illegal! So it is very important that each Pinewood Derby participant be aware of the rules for their Pack’s race (and District race, too)! It would be a shame for a Scout to have his car disqualified because he followed some illegal procedure when building his car!
I know a nother way you can win but i am not telling you.
What is it
what way is that
This will be helpful I have one in March 2015