Determine whether you need a ramp that is 4 feet wide or smaller. If you want a lighter ramp, you could use two 20-inch sections instead of a 4-foot piece and use thinner plywood such as 1/2-inch plywood. That way, the ramp would be easier to manage.
Prepare the materials for assembly. Lay out your two pieces of pine on a flat surface. Using two boards will allow you to take it apart and stow in in your truck bed beside the motorcycle until you reach your destination. Untreated pine weighs less than treated lumber; however, 5/8 inch is thick enough to provide sturdiness. Bolt the center of the ramp together using two 2-by-4-inch studs. Glue the two boards together, using a construction adhesive, such as Liquid Nails. Screw in deck screws that are 1 1/2 or 2 inches long anywhere you want to reinforce the two boards so that they remain together securely.
Flip the ramp on to its long edge facing the tailgate. Attach tailgate horns on each side of the ramp and position the ramp so that the tailgate horns rest snugly on the tailgate in a secure fashion.
Use one or two ratchet straps to wrap around the tailgate and the truck bed while passing through the 1-by-2-inch space in the ramp section. You need to secure the ramp to the tailgate with the ratchet straps to load and unload your motorcycle on the the ramp.
Paint the ramp with one coat of urethane garage floor paint and sprinkle sandbox sand on the ramp while the paint is still wet. You want to apply a nonskid surface to the ramp. Once completely dry, sweep off any excess sand and apply another coat of urethane on the ramp. The ramp will then have a nonskid grip even if it gets wet.
