Introduction: No Weld Single Wheel Bike Trailer
A simple to build trailer with easy to find parts has been a goal of mine for a few years. It had to fit various styles of bikes and carry different loads or containers. This is the result of brainstorming with many like-minded friends. It has lasted through load tests and distance trials. This design has been through two workshops with a community bike shop that I volunteer with, and people with various degrees of skill all managed this build. You will need a hacksaw and a drill with a good collection of drill bits.
Step 1: Selecting the Bike Frame
You will need to cut up a bike frame for the main part of the trailer. Choosing the best frame for the job makes this easier. Choose a steel frame. You need to find a frame with this plate on it. This plate is found where the rear brakes attach. There should also be a plate where the kickstand attaches. You will have to strip the frame of all cables and gears. The seat and pedals are also unnecessary. The part where the pedal arms(cranks) attach is called the bottom bracket, this will become the pivot point of your trailer.
Save the wheels and front fork. You can use any wheel that fits, but I recommend using the same size as your bike uses so you only need to carry one size of tube when you travel.
The front fork is removed and kept. It should fit where the seat tube came out, and the seat post clamp should tighten enough to hold it in place.
There are special tools for working on bikes, I highly recommend finding a community bike shop near you to help with stripping the frame if you have trouble. The crank arms can be especially troublesome without proper tools.
Step 2: Other Hardware
Don't be alarmed. The picture is from the workshop I ran and this shows the hardware for 10-12 trailers.
The door hinge is there to show how they are modified. I cut the pins off with a hacksaw to have access to cheap metal plates that everyone should have laying around. The holes in the hinges become helpful as drill guides in later steps.
The shoulder bolts will be the trickiest part to find. If you live in or near a large city, a bolt or industrial supplier will have them. the third picture shows a close-up of various shoulder bolts.
Step 3: Cutting Up the Frame
Cut the frame with your hacksaw along the lines shown in the first photo. A friend can help here to stabilize while you cut.
Careful when you cut the rear triangle that you cut near the plates, but don't cut the plates off from the rear triangle. These plates are important for joining to the bottom bracket.
Step 4: Bending the Rear Triangle
Once this piece is separated from the frame, it needs to be bent. The photo is the best way to describe this process.
A two by four is wedged into the triangle and held in place while foot pressure is applied on top til the top tubes are parallel to the bottom tubes.
Step 5: Attaching the Parts
This is where it starts to look like a trailer. Stick one end of the bottom bracket in the hole for the kickstand and attach with a nut. Next, take one of the hinge plates and drill it on one hole to fit the other side of the bottom bracket and bolt it on.
The hinge plate should reach the brake plate on the rear triangle. Either drill mounting holes, or match mounting holes, plate to plate. Make sure to use two bolts in the brake plate to eliminate twisting.
As I said before, stick the front fork into the other end of this pipe and you will see the main body of the trailer taking shape.
Step 6: Mounting the Trailer to Your Bike
The large washers are drilled to accept small bolts and springs that will allow you to attach and secure the trailer to the hitch plates. I found the small bolts from U-lock mounting clips to be perfect.
The springs are from brake and gear adjustment screws found on some bikes.
You may need to drill a hole to mount the spring bolt so the washer fits over the head of the shoulder bolt. This is what holds the trailer to the bike without falling off.
Check the pictures, sometimes they are worth thousands of words. The plate held in the fingers in the third picture is drilled to fit your bike's rear axle. If you have quick release, no drilling is required. You can use the existing hole. Just make sure to mount the plate tightly to your bike.
Step 7: Mounting Crossbars(handlebars)
The crossbars are mounted in two different ways. Depending on your use, this can vary. I used a steering stem from a more modern bike at the front of the trailer. Use a steel one, aluminum will break when you try to stretch it over the pipe. Spread open til it just fits over, then squeeze it closed and clamp in place using the screws it came with.
At the back is where I used the hose clamps. In the picture, the clamps go where the zip ties are holding the handlebar on.
The U-bolts are used to fasten your box/crate or platform that you decide to use. I used a bakery tray, used for delivering bread and buns to stores, on one and a storage tote for the other.
Thanks to everyone whose input helped make this build possible. The Wrench, for access to tools, and friendly advice, and Benita for the many great pictures from the workshop.
Happy building!
18 Comments
4 years ago
i love it!
Tip 5 years ago
Showing open and closed position for spring and washer assembly. Hole in washer fits over the head of the bolt on the plate on the bike. The spring holds the washer in position.
5 years ago
I have been working on the hitch and I do not think it can be assembled with only the description and photos published. Can you elaborate? Thank you.
Reply 5 years ago
Sorry about the delay. Extended trip away from home and computer. These are close ups of the spring and washer assembly from perhaps a better angle. This is on the trailer and connects it to the plates and bolts on the bike by springing over the head of the bolt on the plate attached to the axle of the bike.
Reply 5 years ago
Do you have the shoulder bolt and hinge plate? Or is it the spring/bolt/ washer part that is confusing to you? I can describe it if I know exactly what you need described.
5 years ago
hi how is called this type of frame with a plate?
anyonw can give the name of the bike model?
Reply 5 years ago
These are all older frames. Mostly from the 1980s and 1990s.
Reply 5 years ago
Any bicycle frame that has that flat plate above the rear wheel will work. It is where the brake caliper mounts. Most of these frames have a one inch seat tube, which will match nicely with the front fork, which is also one inch. I have used any department store quality frame for this. Just look for the most ordinary bikes, no suspension or extra large frame tubing. Raleigh, CCM, Norco, or other local store brands will work.
6 years ago
I am trying to understand the connection to the bike.
"You may need to drill a hole to mount the spring bolt so it fits over the head of the shoulder bolt. This is what holds the trailer to the bike without falling off." I don't understand. Perhaps "it" refers to the washer?
"The plate held in the fingers in the third picture is drilled to fit your bike's rear axle. If you have quick release, no drilling is required." Is the plate only attached to the bike by the axle? If so, it would seem that there would be a problem with the right axle nut tending to be loosened by the weight of the trailer. Also don't understand why quick release would change things.
Do we assume that the plates remain on the bike and the trailer is attached/detached from them?
Probably I am just dense, but I do appreciate the cleverness of the design which utilizes the donor bike so efficiently. Nicely done!
Reply 6 years ago
Sometimes the frame you find has multiple holes for fender mounts or racks, and you might use these if it allows the washer to fit over the head of the shoulder bolt. The washer must be able to reach over the head of the shoulder bolt when the bolt is engaged in the slot. The weight of the trailer loosening the nut has not been a problem as of yet. The right side of every bike I have tried has other gear on the right side to prevent turning. And yes, the plates remain on the bike while the trailer can be attached or removed. Thanks for the compliment, many suggestions along the way, and several builds have helped with this design. Sorry if I wasn't clear, the design is open to modification.
Reply 6 years ago
Actually I misread the post myself, hopefully I can clear this up. You may need to drill a separate hole near the slot in the dropout of the bike(soon to be trailer). The picture from the side showing the spring and bolt attached was drilled in this way. Sorry for the confusion on my part.
6 years ago
This is great...I've been trying to think of a carrier for my dog in the back of my bicycle. I'm going to give this a try. Thanks.
6 years ago
neat build, I respectfully suggest a spring loaded 5 wheel at the cart front, so it can go up and down with bumps, but regardless of standing still or rolling on it takes pressure off the hitch.
As is I bet this last years, but a 5th wheel plus sealing the tube could extend life. They may be gilding the lily, but it seems it would be worth it, this is a sweet simple thing WITHOUT welding.
woof! happy dog!
Reply 6 years ago
I loaded this trailer in its current design with 55 lbs. and rode 500 miles over 11 days through 9 days of rain. the pivot point withstood all the bumps of lousy highways and gravel roads. Tried to keep the build simple and straight forward.
Reply 6 years ago
if you were to add another wheel, it would have to be a caster so you could go around corners. Since this design has to maintain a straight line in the vertical plane between the trailer axle and the bike axle, adding a support between them would add stress rather than reducing it. The pivot between the hitch and the trailer can have no up and down movement.
6 years ago
Well must say that would have been nice when I rode a bicycle,LOL.I would have used.But now I guess I'd have to show the grand kids how to DIY one .Thanks for the idea. ;-)
6 years ago
Next, merge this with a Solar recharged electric bike.
Actually, that might be a neat research topic.
6 years ago
Great idea. I need to do this with my bike. It would make biking to the grocery store a lot easier.