How to Build a Motocross Foam Pit

Many variations of foam pits have been built, using everything from above-ground swimming pools to wood or masonry block structures and even large high-quality metal enclosures. USA Gym Supply states that pit foam needs to meet specifications to ensure durability and proper firmness and to meet building code requirements regarding flammability.

Things You'll Need

  • Crane or winch system (for lifting bike out of pit)
  • 100-foot chalk line or can of neon spray paint
  • Small wood posts or stakes
  • Hammer or mallet
  • Front-end loader
  • Post hole digger
  • Concrete mix and water
  • 12-foot, treated 4-by4-inch wood fence posts
  • Sand
  • Pea gravel
  • Ground tamper
  • 4-by-8-foot sheets of 3/4-inch plywood
  • Table saw
  • Drill
  • Wood screws
  • Foam - Furniture, Mattresses, Sponge, etc.
  • Vinyl Tarp(s) to cover pit when not in use
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Instructions

    • 1
      Looking for a suitable foam pit location

      Find a suitable level location for the foam pit away from all obstructions. Hammer stakes into the ground where the corners of the foam pit will be located. Ensure that the pit will be large enough to land in and avoid injury to the rider.

    • 2

      Mark the lines of where the foam pit walls will be, using the chalk line or spray paint.

    • 3
      Bulldozer removing dirt for the foundation of the foam pit

      Remove dirt to 6 inches below the surface, using a front-end loader.

    • 4
      Posthole digger for digging post foundations

      Dig 12-inch diameter by 24-inch-deep postholes every 8 feet around the perimeter of the pit. Center 4-by-4 posts in the holes and fill the holes with concrete. Allow time for the concrete to properly set up.

    • 5
      Compressing the foundation

      Spread a 2-inch level bed of sand in the bottom of the pit. Fill the remaining excavated area with 4 inches of pea gravel, and compress the fill, using a ground tamper. The fill will allow water to drain from within the pit.

    • 6
      Plywood sheets used for the sides of a foam pit

      Cut 3/4-inch plywood sheets as needed with a table saw. Attach the plywood to the outer edge of the 4-by-4 posts, using a drill and wood screws.

    • 7

      Fill the pit with foam cubes to a depth of 6 to 10 feet. Foam can be purchased or made by cutting furniture or mattresses as needed to create cubes. Polyurethane foam cubes with a fire-retardant additive can be purchased.

    • 8
      Vinyl tarp being unfolded

      Move the ramp into the desired location as needed. Use a crane or winch system to lift bikes out of the pit. Cover the pit with vinyl tarps when it is not in use.