Conversely, if there is too little traction on a tire, the car will slide. Students need to find a level of traction that won't cause the car to slip, but won't waste valuable energy. This will solve the traction problem without adding additional weight. Bearings Bearings are the components in the wheel that allow the relative motion of two parts. They also support the axle with the wheels attached to it.
Lubrication helps parts slide against each other and it is used to reduce friction in the bearings.
Students should experiment with different lubricants to see which works best for their car. If the edges of a wheel rub on the body of the car, it creates a lot of drag. The axle holds the wheels and supports the car's frame. A larger axle takes more energy to turn than a smaller one. Surface finish is critical, so make sure all of the running surfaces are as smooth as possible.