Building a motorcycle trike is not as complicated as it may sound. All that is needed to build a trike is a little bit of ingenuity, an existing motorcycle, some machining skills and a friend with a little extra time on his hands. Motorcycle trikes are three-wheeled motorcycles that can seat one to two people comfortably. Many trike enthusiasts like their motorcycle trikes because of their increased stability, smooth ride and increased capacity for carrying luggage. As freeing as riding a motorcycle, but with the ability to carry all of your stuff, trikes are a fad that is not going away.
Securely prop your motorcycle up on the jacks and remove the rear wheel by loosening the two castel nuts on either side of the rear axle, sliding the rear tire slightly forward and sliding the chain off of the sprocket. You can now pull the rear wheel free from the swing arm. Pull the rear axle out of the hub and examine it. Depending on how wide you want your trike, you could manufacture an axle of any length; however, we will assume for the purposes of this article that you are going to build a trike that is half as wide as it is long.
Determine the length that the rear axle will need to be in order to meet these dimensions and then subtract the length of the existing rear axle from that. Divide this number by two and you now have the length of axle that needs to be welded to either side of the existing axle to make your trike work. Use the lathe to turn some of the steel down to match the thickness of the existing axle and cut the steel to match the lengths needed. Weld each piece of steel to each end of the axle (making sure that they are perfectly square).
Weld the wheel hubs to the ends of the new, larger axle and slide the axle into place on the swing arm. Tighten down the castle nuts and reinstall the chain on the sprocket. Attach the two trailer wheels to the ends of your new axle by sliding the wheels on the wheel hubs and tightening down all of the lug nuts. You can now either leave the trike assembled as is or add fenders to the two back wheels by bending the sheet metal up and over the tires, bolting into place along the frame and painting with the colour of your choice. Take your trike for a test ride.
Many used trikes can be found on the Internet or at local dealerships. If you are not overly skilled on the metal lathe or with the welder, it is recommended that you buy a pre-manufactured trike.
Do not weld the axle together crooked as this will cause a terrible and dangerous shake at highway speeds and could cause an accident or damage to the bike.