How to Build a Soapbox Racer Car

One of the simplest ways to build a soapbox car is with a wagon.

According to Monster Guide, "Soapbox derbies are a favorite competitive sport among adolescents and teenagers." For decades, young and old alike have enjoyed the hobby of building soapbox cars. A soapbox racer is a car built from a variety of materials utilizing a steering and braking system. The race takes place on a sloped track which enables the car to move around the track without a motor, powered by gravity. Making a soapbox racer requires some preparation and planning, but that is a part of the overall racing experience.

Things You'll Need

• Wagon
• Lightweight metal pipe
• Axles
• Wheels
• Five-point harness seat belt
• Hammer
• Wrench
• Screwdriver
• Drill
• Jig saw

Instructions

1. Design your soapbox racer. Most builders purchase blueprints that can be found online or at a hobby store. Generally, with the prints, you should get a list of materials and tools needed to complete the project. Another easy option would be to purchase a soapbox racer kit. The kits consist of pre-fabricated parts that are ready to be assembled. An experienced builder may want a more challenging option of designing and building a racer from scratch using materials found at local junkyards, neighborhoods and lumber suppliers. Always keep in mind, though, that if a soapbox race is going to be entered, one must adhere to the rules, regulations and specifications for competing in that particular race.

2. Build a durable chassis for the vehicle that will hold all the parts together. The chassis needs to be strong but lightweight. The design is important because it determines the shape of the body. Most racers choose an oval shape for the efficiency and speed. A light metal pipe is recommended when building the frame to keep from weighing the car down. If the car is too heavy, it may tip over.

3. Assemble the drive-train, which involves assembling the axle, wheel system and brakes. Unless you are experienced in this area, always follow the instructions on the plans closely. Improper assembly can cause serious injury. To be able to maneuver the car, the front axle should be connected to the steering column. One option for wheels would be the baby carriage design with slightly larger wheels in the rear. Putting the smaller wheels in the front will give the race car more control and stability. And, of course, making sure the braking system is correct is a essential because without brakes the driver can't stop.

4. Assemble the body of your soapbox racer. The body should be strong enough to protect the driver and ensure their safety while racing. For better safety, reinforce the body of the car with trusses, or a roll cage for additional safety. A five-point harness or seat belt can also be added. The car can now be painted. Most any type of paint can be used, with any color and design. Double-check with the racing authority for rules and regulations.

5. It is now time to test your soapbox racer out. Adolescents should do this under adult supervision, and ensure that the braking and steering systems are working properly. After a few test runs, and when you are confident all systems are go, then it is race ready.

References

• Monster Guide: How to Build a Soap Box Derby Car
• Best Cars Guide: How to Build a Soap Box Derby Car
• Mission Museum: Build a Racer
• Kidzworld: Soap Box Racing
• Top Cool Cars: How to Build a Soapbox Derby Car

Resources

• Kart Building