To build a downhill racer, construct a seating area from wood or use a crate as the seating area, and attach four wheels to it. The process for building a downhill racer varies depending on the type of racer you want, as the only requirements for a downhill racer are that it's gravity-powered. Common downhill racer features include a steering wheel, brakes and sides.
Plan your downhill racer by sketching a blueprint beforehand or downloading one. An alternate option is purchasing a downhill racer kit. If you purchase a kit, construct it by following the instructions. When you design your racer, you should also create a budget and decide on the types of materials you want to use. Wood is easier to use, but metal is more durable.
For optimal results, design the racer so it makes as little contact with air as possible. This minimizes drag and makes the racer go faster. Heavier racers can achieve faster speeds, and lighter racers maneuver more effectively. You also need a steering wheel for turns. Instead of buying all the parts you need for a racer, you can use parts from around the house, such as bicycle tires or go kart steering wheels.