A bike pump track is a series of rollers and berms built in a loop that, if correctly designed, can be ridden continually without the need for pedaling. Forward momentum is maintained by "pumping" the bike through the roller sections. Riding on a pump track is a highly effective way to build biking skills and techniques such as balance, cornering, speed maintenance and stamina. Pump tracks can be built in a small space, providing a safe venue to progress from novice through expert levels.
Decide where you will build. Choose a flat piece of land with a minimum building space of 40 feet by 20 feet, though more is better. Ensure that you have full permission from the landowner to proceed with your project.
Draw up blueprints for the pump track. Design the track creatively so that it makes the best use of the area available to you. You are not limited to a simple circle loop; experiment with various possibilities, such as an "L" or figure-eight loop. Start by laying out the turns with a diameter of between 38 inches and 75 inches. Turns that are closer to 38 inches will be very difficult to navigate, but will produce expert skill over time. Wider turns are preferable on a pump track open to a wide range of users. Allow about 3 feet for the track width.
Dig. Begin by marking the area of the track according to your design. Work on one section at a time. Shovel dirt into the dimensions of the track and pack it down. Wet the dirt so that it will compact well and dry hard.
Build up the rollers with additional dirt. The high point of a roller is a tip and the low point is a trough. A good roller is between 1 and 2 feet from tip to trough and rollers should be spread out about 90 inches from trough to trough. Narrower rollers are harder to navigate, but they produce more speed and skill.
Build the berms. Make them low on the inside and gradually higher and steeper toward the outside. The higher and steeper the berm, the faster it can be ridden. Expert riders enter a turn quickly and lean up to 70 degrees into a berm. Slower novice riders roll through the berm at a lower, less-inclined point.
Test the track on your own bike. Smooth out any rough spots with the shovel. Redesign the shape and size of problematic rollers and berms by adding or removing dirt.