Turning a piece of waste ground into a bike track is a serious project but individual jumps can be built up out of the earth in a matter of hours and can be easily modified to suit the type of jump you want to achieve. Undertake the project with a group of friends to make this a more enjoyable and manageable task.
1. Plan out where and how you will build the jump. Take into account how much speed you will need to clear the jump you want to build and how much run-up distance and downhill you will need to achieve this. Work out how much distance you will need after the jump to stop or turn and make sure there are no obstacles in the way. Remember that a large jump will need a down ramp to land on as landing onto a flat surface will result in high impact and possibly injury.
2. Pour flour onto the ground to mark out the outline of the course.
3. Make the skeleton of the jump ramps by piling logs into shapes appropriate to the shape of the jump you are making..
4. Pack earth over and against the sides of the log piles, bashing it tightly into cracks between the logs with the spade
5. Smooth the ramp down making sure that there are no sharp angles between the track and the start of the ramp. Pour water over the ramp and pack it hard again to make it solid.