By John Kenthol

There are many ways to build jumps, and none of which are wrong providing they work. What follows here is an overview of the basic ways to build good, long lasting jumps.

The very first thing to do before heading out and digging jumps is to choose a location. This may seem pointless as jumps theoretically can be built anywhere there is dirt. However a location can make or break/get jumps destroyed. The best location you can find will have a combination of things:

Dirt - All dirt is not created equal. Dirt with a clay base is best for jumps. Sandy dirt is not good for jumps because it does not pack and they will fall apart. The best dirt will have very little or no rocks and stones, pack nicely when moist and become rock solid when dry.

Easy access (for you) - Close to where you & friends live yet out of the way of major trails/ public areas. While dirt jumps are gaining awareness and acceptance they are still generally not supported by the non biking public. Make them out of sight and out of mind.

Water - To keep dust down and keep things build-able all year long

Elevation change- Jumps can easily be built on flat ground. However a slight downward slope is usually best, especially for the run-in. Jumps that feature more sudden elevation changes can also be a lot of fun and sometimes easier to make. Use a steep hill as a roll in, or a step up, or even create a hip on it.

There are many other factors that can come into play when choosing a location but these are the main things to consider when choosing a spot for jumps.

Now onto the good stuff, creating the jumps!

How you build your jumps will vary with the type of location you have chosen for your jumps. Here are the three main ways of building jumps.

1: “Naked” jumps. These jumps are usually found in older forests under tall trees. They are packed piles of dirt totally exposed. The trees above provide cover from rain for these jumps so they do not erode. With large trees roots are common. However they are usually spaced apart far enough that digging is not too much of a problem. These jumps can be prone to erosion over the winter months when leaf cover is non existent. Also, if not fully packed erosion is common.
This type of jump is the most simple to build but requires the most dirt, just pile it, shape it, pack it and ride it.

2: “Grass wall” jumps. These jumps are found in open fields where sunshine is abundant. Grass can be built with the jumps using cubes, (recommended) or can naturally grow on the jumps after a few seasons. These jumps are prone to erosion from rain and winter weather if not covered with grass.
This type of jump can be difficult to build, however will take less dirt and be extremely resilient if done properly. When building a jump in a field, use a spade to cut cubes of grass out of the ground. Lay these along the ground around the footprint of the jump with the grass facing out. Then fill the inside of the jumps footprint with dirt. Once filled just above the top of the grass cubes, stack a new layer of cubes on top forming a retaining wall of grass. Sides of a jump or the back of a takeoff or landing can be made near vertical with the grass cubes.
Hint: When cutting the cubes cut as absolutely deep as possible, the thicker a grass cube is the stronger it is and the better it will hold up the jump.

“Wood wall” jumps: These jumps can be found anywhere and take the least amount of dirt. They are usually faster and easier to build than a grass wall jump and if built correctly are by far the strongest most resilient jumps possible.
The easiest way to build these jumps is to drive long stakes into the ground (at least 2x4’s.) Drive them down to a depth of at least 2-3’ but the deeper the better. Use plywood to hold back dirt between the stakes. Have the stakes stick up to the height that the plywood will holding back dirt to, if you have a 4’ tall jump use 6-7 or 8’ long 2x4 stakes driven into the ground so only 4’ is showing to hold the plywood vertically.
Hint: Plywood should be used and not OSB (oriented strand board) or particle board. If OSB is used it will hold water and deteriorate within a couple seasons.
Logs can also be used to help hold up jumps. However it is usually faster to pile up dirt to create a jump rather than scavenge logs to fill up a jump.

Other Tips for building great- long lasting jumps:

When building jumps build them big, wide, and strong. Spending an extra 30 minutes making the lip of a jump deeper and wider will mean a lot less maintenance down the road. The average larger jump (4’ tall or larger) should have a takeoff never less than 3’ wide (in ride-able width) and a landing should never be any narrower than 6’. The larger the jump and gap the wider the landing needed.

Do not dig pits. There are almost too many reasons to list on why not to dig pits yet it is still always done. They collect water that breeds bugs. Hikers/visitors to the jumps can fall in and sprain an ankle. And the pit is in a very bad spot; an out of control landing could send a rider into/towards a pit--which never goes well for the rider. If a pit is dug between the jump and a landing it can increase the rate of erosion and some of the jump may end up in the pit during the next rain storm. Instead, dig from a large area and gently slope all sides so that it is almost unnoticeable that any amounts of dirt have been removed.

Dirt can usually be used from directly in front of the takeoff as well as the bottom of the landing path. Care must be taken not to lower this area too much or it will become flooded after rain.

All jumps are prone to some erosion in places that are ridden. The face of jumps and landings can be covered with old carpets or any thick cloth coverings to slow erosion.
This is also a great way to keep dust down.

Keep the dirt jumps clean. Pick up all garbage and keep everything as natural as possible. If a non-rider happens to find them they will not care that the jumps are there providing they pose no hazard to them (pits) and there is no litter. The use of carpets to cover jumps may also be seen as littering to a non-biker, so be careful when using them.