Build your own Motorcycle Trailer

Now that you're not building a trailer, here is the scoop!

Size

• First decide on what you will carry and how much weight is involved. I would recommend not going overboard in this area. Remember it's easy to get going but not so easy to stop especially on wet pavement.
  
• Typical dimensions = 32" wide 44" long 14" high (We'll use these dimensions for plans)
• Max load weight - 150lbs (trailer will also weight approx. 100 lbs for 250lb total) This could include, tent, stove, clothing, lantern, golf clubs and fishing gear.

Frame

1. I used 2" x 2" steel punched angle for the frame. This material is easy to work with and doesn't require any drilling for mounting springs, shocks, or the main box.
2. The hitch tongue can be 1-1/2" x 1-1/2" square stock or "T" bar (I used a garage door opener rail)
3. Weld the frame together as shown View Checking for square by measuring diagonals across the corners or use a carpenter framing square. The spring/shock units came from an old snowmobile front suspendsion - They can be located at any bone yard in the northern states. You southern types may have to check out the mail order parts yards on the web, or trailer supply stores. If you send me E-mail I could give you some phone numbers of area suppliers - new & used.
4. The frame should be 2 inches narrower and shorter than the "box" ( 30" x 42" typical) this way the box will overlap the frame 1" all around.
5. The axle center should be 4 inches behind the trailer center point, this will give a positive trail and forward weight shift to keep the unit from wandering. The rearward ends of the springs "slide" back and forth on the frame, only the front is bolted. I drilled & tapped a hole just above the rear spring contact area and installed a grease zerk, I also drilled a 1" hole in the "Box" bottom over these areas so I could inject a little grease once in a while.
6. The Coupler is designed to swivel approx 20 degrees, this way if the trailer is on an uneven surface while in a 45 degree or greater turn (as in backing up) the hitch won't bind. A small 1/4" rod is welded to the rear of the main pin to limit the pivot to 20 degrees.
7. The wheels are from a mini bike - go cart wheels work real well also. approx. 13" in diameter with a speed rating of 90 mph and weight carrying abilty of 200 lbs per tire. go cart wheels can be "mag" style - sharp.
   

The Box

• The Box is just that, a wooden box 32" x 44" x 14". I use a plywood material called "Nova Ply" it is available at all lumber yards. This material is 3/8" or 1/2" thick plywood with a brown paper covering. This material paints up like sheet metal but is much easier to work with.
  
  1. Build the box as a closed cube, (paper side out!) don't build the bottom and a separate lid, install 1x2's in all the corners for strength. If you have access to pneumatic finish stapler, you can use this with 1" long staples or just screw the whole thing together with drywall screws. making sure the edges are fit flush and the screws are slightly sunken. The bottom of the box can be standard 1/2 plywood (CDX grade) as it is cheaper and will not show.Glue all joints and corners.
  2. Now it's time to cut the box open and form a "lid"
  3. Set up the fence on the table saw or the guide on your skill saw to 2-1/2". cut one of the long sides first, but cut only one side for now.
  4. With one side cut install a piano hinge (30" long) Hinge view. After the hinge is set, just finish the cut around the box. Glue a piece of 1x2 along the cut joint - front,back & latch side, leaving it stick up into the lid approx. 1/2". When closed this projection will stop water from seeping in and also keep the lid alined. I used a couple 30" lengths of 1/8th inch nylon cord as a stop for the lid, the cords just fold up into the box when it is closed.View
     For latches just use a couple suitcase latches or hasps - available at any hardware store or lumber yard.
  5. Optional - Install fenders this is up to you. I bought these fenders at Northern Hydraulics for $7.00 each , it's just a nice touch.
     BTW phone numbers:
     (612) 894-0236 (MN)
     (515) 252-1516 (IA)
     (804) 552-0726 (VA)
     (813) 489-3335 (FL)
     (210) 334-4294 (TX)
     they have stores all over the US. Lots of neat stuff, pumps, engines, trailer wheels & axles etc, go kart , motorcycle/snowmobile parts. Call them for a free catalog or three!!
  6. Next - mix up some auto body putty and putty over the screws/staples and any uneven edges, sand smooth and paint the trailer box with a good automotive enamel paint - feel free to get fancy!!
  7. Install tail lights and that licence plate, carpet the interior so stuff doesn't rattle and your finished with the trailer portion of this project.
     

The Cycle Hitch

• Your probably wondering, why not use a ball hitch like on a boat or standard trailer? There's two reasons
  1. There's that big ugly ball hanging off the back of the bike and that equally ugly huge hitch on the trailer.
  2. And the standard ball hitch only swivels about 30 degrees or so. If this hasn't happened to you - it will! The bike is parked on black top and it's 100 degrees out there, suddenly the kick stand sinks into the hot asphalt and "bang" the whole thing topples over. Now if the hitch only swivels 30 degrees and the bike tips 90? what happens to the extra 60 degrees - bend & twist.
     My design will pivot 360 degrees if it has to and is not as over bearing in appearance as the ball hitch.
     

Building The Cycle Hitch

1. You pretty much have to "wing it" when it comes to the construction of the hitch, all bikes are different and the mounting locations are also dependant on things like saddle bags, exhaust systems and chain/driveshafts.
   I thought I would mount mine to the rear foot peg brackets but found out the driveshaft wouldn't clear, so I hooked up under the seat on a couple of frame tabs that were there for ?? who knows what - probably factory bags or something. The rear mount for the hitch is the bolting spot for the luggage rack - so there's (4) spots the hitch acually bolt to - very sturdy. A not so clear view of the mounting
2. For materials you can use 1-1/4" x 1-1/4" heavy angle or 1" x 1" square stock, anthing that will be sturdy but not bulky. You must also consider that the hitch must be resistant to side to side bending, so allow for additinal bracing.
3. I cheated! I had a bunch of garage door opener arms just piled up so I used these to build my hitch. I welded them all together taking advantage of the 90 degree arc in the arms to form the corners - here is a view of my hitch
4. The connector end of the hitch is a large 1/2" "screw eye" which can be purchased at any lumberyard or hardware place. One end of the screw eye is just that an eye or hoop and the other is treaded (1/2" course tread) I put (3) nuts on the eye and then welded the "nuts" to the hitch being careful not to weld the eye to the nuts - it has to rotate when you get done. Here's a close up. of the trailer hooked up.
5. You'll notice there seems to be a lot of space and play in the coupling, this will rattle and wiggle around if left like this so what I did was cut a 1-1/2 washer in half, grind it to fit against the trailer coupling and weld it to the top of the screw eye hitch like shown here This way the play is reduced and the hitch can move up & down freely. Don't be concerned if there is still some play in the hitch - the only time you will notice is driving slow on bumpy roads , like pulling to a stop, under speed there will be a steady pull back on the hitch and it will not rattle.
6. Drill a 1/8" hole in the top of the center nut on the screw eye so the treads can be oiled, this will keep rust from seizing up the treads
7. Wire up the lights - You can get buy without signal lights on the trailer as the bike lights are very visable above the trailer top, however it's a nice touch to have the lights on the trailer also. Locate the wires under the seat that connect to the brake,tail light and the signals and tie in accordingly. I used a standard connector harnes just like a boat trailer or camper set. This set has (4) wires, one for tail,RH signal and LH signal plus ground. Most bikes have the signals and tail lights wired separately so you will have to use the white or ground wire as the brake light wire. The hitch will form the ground through the frame.You will need to install a extra pair of amber clearance lights for signals (the main tail lights will be brake & tail = red)
   Tail light Layout

   Color code
   Brown = Tail lights
   Green = LH signal
   Yellow = RH signal
   White = Brake lights
   Option #2= buy a converter unit (available at RV & Camper places) and install this, it combines the wires so a standard 3 wire hookup will work = costs about $15.00 and may be hard to locate under seat.
   Option #3= mount the converter unit in the trailer
   My tail light package included amber clearance lights - I went that route.

8. Last thing - safety chains - most states (US) require safety chains, just some light chain that will secure the trailer in case the pin drops out. fasten or weld the chain to the trailer hitch and secure to the bike hitch with hooks or chain latches - use a pair of chains not just one. keep in mind that the chains should be long enough to allow turning but not to long as to allow the trailer hitch to come into contact with the rear tire if the trailer comes unhooked.

The Finished Product