Introduction: Hammer Time! Bike Trailer

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This trailer is a hodgepodge of the simplest, no-weld trailer components found on Instructables, friend's trailers, and frustrations via trial and error at our warehouse (shameless self promotion - www.hammertimeprojects.org ) The goal is to make the trailer accessible to anyone who can get a hold of these basic tools and materials...

Tools (borrow from a friend )
-Hacksaw (angle grinder and miter saw optional)
-Powered drill with steel bit, 1' wood bit, Phillips bit
-1" Conduit bender
-Calipers (optional)

Materials(acquire at a used building materials store, bike co-op, and construction site dumpster.)
-15' or so of 2x4
-6' or so of 1” diameter conduit
-2 any size bike wheels (front or rear)
-1' of angle iron (bed frame works great)
-busted bike tube
-garden hose
-2 large hose clamps
-screws
-heavy duty staples (optional)

Note! you will find there are no exact dimensions in this Instructable - this is not because we didn't measure anything, but rather to let one build the trailer based on its function and to allow one to incorporate materials that may be laying around.

Step 1: The Frame

Step 1: Cut the 2x4s to your desired dimensions and lay out the frame like in the first picture bellow. I think the total frame dimensions we used were about 2' x 4'.

Step 2: Take your bike wheels and measure the width of each axle from inner nut to inner nut using a caliper tool, ruler, or string. It is important to measure both bike wheel axles as they may differ (a front wheel as compared to a back wheel with a cassette).

Step 3: Space the 2 lateral sets of 2x4s on the left and right of the frame (circled in pic 4) as wide as each wheel axle (pic 3)

Step 4: Cut 2 more 2x4s as as long as the width in between the lateral sets (pic 4).

Step 5: Screw all 2x4s together with 2 screws per joint (pic 5).

Note! Screw the frame from the most inner 2x4's to the outer as to not block the placement of your power drill.

Step 2: The Dropouts

Step 1: Using a miter saw with a steel wheel, angle grinder, or hack saw - cut 4, 3" (or so) long sections of angle iron (an old steel bed frame works great).

Step 2: Using an angle grinder or hack saw - cut 2 slits inward from one side of the angle iron leaving a space in between the slits barely wider than the width of the axle (calipers work well to measure this). Bend the steel pieces in between the slits until they snap and create a notch that can seat the wheel axles (circled in pic 4).

Step 3: Drill 3 holes in the shape of a triangle on the opposite side of the angle iron. Choose a steel drill bit that is wider than the body of the screw you use, yet thinner than the head of the screw.

Step 4: With the wheels seated and bolted to the dropouts, place the wheels in between the lateral sets of the 2x4s 6-12” back from the center of the frame. Position each wheel so it lines up perpendicular to the 2x4s. Screw the dropouts to the frame.

Step 3: The Pull Arm: Prepping the Frame

Step 1: Measure and mark spots in the center of the front 3 horizontal 2x4s (the 3 closest to where the hitch will protrude from).

Step 2: Using a drill bit the same diameter of the conduit you will use for your hitch (we used 1" conduit for strength), drill the 3 holes.

Note ! Use a test scrap of 2x4 to drill a whole and see if your conduit fits snugly through it. If it is too small, you can use a wood file or jigsaw to carve it out.



Step 4: The Pull Arm: Bending

Step 1: Measure and mark from one end of the conduit a foot or so greater than the distance between the 3 holed horizontal 2x4s. Using a hefty conduit bender bend the length of conduit at the new mark to curve just above the back tire of your bike.

Note! Bending conduit is tricky! Kinks are bad! (pic 3).

Step 2: Using an angle grinder or hack saw - cut the conduit where it meets the seat post.

Step 3: Insert the conduit through the 3 holes in the frame until it meets with the first bend.

Step 4: Using a steel bit drill a small hole down through the top of each 2x4 and through the conduit where the conduit intersects with the 2x4s. Sink a screw into each small hole to fasten the conduit to the frame.

Step 5: The Hitch

Step 1: Cut a 1' section of garden hose over a 1' section of bike tube (thicker the better - maybe even double it up).

Step 2: Using 2 large hose clamps clamp the section of garden hose over the section of bike tube leaving a space about the diameter of your seat post in between the hose and the tube.

Note ! If your seat post clamp is too thin or too close to the wheel, scavenge one that fits off an old frame and clamp it wherever you want to your seat post.

Step 6: The Bed

 To reduce weight I cut and fit an old steel cage to the frame and fastened it with heavy duty staples.

Note! Alternatives could include the back mesh of a fridge, the bed of a shopping cart, or some ply wood. Get creative and use bike tubes for bungee chords or make walls out of whatever is laying around.

Step 7: Dang! You're Done!

Wow! Good Job! Haul groceries from the store, compost for your garden, and even your friends! Stain or paint it for weather protection and street cred. Make different variations and sizes of this design for different uses (I have a similar larger one that has pulled over a half ton!)