Bike Trailer Hitch





Introduction: Bike Trailer Hitch

About: I live in the south Italy countryside, I have plenty of room to mess up with drill, grinder, saw and other stuff. I'm loving it.

This is a very cheap Hitch made with a swivel caster, a bracket for antenna poles and  a piece of square iron pipe.
To be fixed under the bike saddle.
Great just because it allows the movement on three axes, so there's complete freedom while biking.

Step 1: What You Need

A swivel caster with bolt. Make sure to buy a wheel that can be removed from the frame, just removing the axle bolt.
A cross bracket for antenna poles
Self-locking nut

Step 2: Disassemble the Wheel

Just remove the axle bolt and take away the wheel that you don't need.

Step 3: Assembling

Drill a hole in the middle of one of the hump on the cross bracket. The hole should allow the bolt of the frame of the swivel caster to fit in.
Lock the bolt with the self-locking nut.
If you want, you can cut the exceeding bolt thread with a grinder before assembling.
Using the grinder, shape a piece of square 30x30mm iron pole as shown in the picture, then drill two passing holes, one for each axle, and fix the piece to the wheel frame by the horizontal axle.
The iron piece will allow the vertical movement, the trailer bar that is going to be attached will allow the horizontal movement and the bearing of the wheel frame the torsional movement.
A simple steel pin will be used to fix the trailer bar to the hitch.
That's it



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    You can simplify this part by getting a flat based bolt on casters, and making a couple saddle straps instead. It will also be stronger than using pipe brackets. Add a little rubber into the mix in the form of a flat pad the full size of the caster base, and rubber pads on the contact side of the straps. This will help prevent slippage, and protect the bikes paint as well. Good reengineering with what you had available. You can also swap your bolt on the trailer yoke with a scaffold pin, or a slip pin setup for easy removal.



    Hello. I am very interested in building one of these setups. Do you know which hardware stores in the US would carry a cross bracket for antenna poles? Antennas aren't very popular anymore in the US, so I think this may be difficult to find. Thanks!

    3 replies

    Look for a caster with a flat mounting plate. Then all you need is all-thread, u-bolts, or even hose clamps to fasten it to the post.

    I'm building a similar mount at the moment using slightly more expensive materials. I'll post some pics when it's completed.


    Hi, i am sorry but i am located in Italy and i have no clues. You might show the pic of the cross bracket to ppl in an hw store and let them address you. Maybe a store that sells supplies for CB/Vhf equipment enthusiasts (do they still exist? ). Thery still use antennas.
    Buona fortuna!

    Thank you for your suggestions my Italian friend. Unfortunately I have gone to every store in the area looking for this and I showed them the picture too. Nobody sells this equipment here anymore. They only sell these things if you have the large antennas (not TV related) and the brackets are too big for those. They suggested I make the part myself. I ended up finding a used child bicycle hitch (so your kid can ride behind you attached to your bike) and I'm going to use that as the hitch to pull the kayak trailer I am going to make. Thanks again for your help.

    Awesome use of everyday materials. I'm curious about shots of the child's bike side. Could you post those please?

    this is brilliant

    Thank you again for your help on this! I was able to successfully build your hitch (here's what mine looks like), but I have discovered that it was the wrong solution for my problem. You built this, I think, to pull a cargo trailer, with two or more wheels. That system is self-stabilized, and you need the three axes of freedom at the lead end.

    My goal is to tow my daughter's two-wheeler, and in this case those three swivel axes are way too many :-/ Her bike tips over, the towbar wanders all over the place, etc. I've had to back off to using a fixed mount on my seat post, and will come up with a cleaner design than the hack I have right now.

    2 replies

    Yes, you need a 2 swivel axes, not a three if you don't want to pick up your daughter from the asphalt with a spoon... :-) . But this should be an easier task. If you have a projext already, keep on going, otherwise let me know, I'll try to figure out some easy and unwelded solution....

    I got it down to a fixed fitting (with a tightened vertical bolt) at my end, but I haven't done a good job locking the front fork on the trailing bike. I'm going to try a couple of threaded rods down to attachment points at the front axle.

    I'm working on integrating this nice design into a towbar I'm building. It would be quite helpful if you could add some steps showing the cutting and assembly of the rest of the hitch, in particular how the box beam is cut, and where the axle holes are drilled in the box beam and the trailer bar itself. Did you use sleeve bearings on the two axles, or just bolts?

    I'm likely need to order some parts online, so having dimensions would be really helpful. What diameter is your trailer bar? What size box beam did you choose to fit it? What size caster did you need for the box beam to fit?

    4 replies

    Sorry, I have no pics of the ongoing cut but i can take some of the disassembled hitch to show the cut and holes. In the holes i just used bolts but the sleeve bearings could be a good improvement.
    About the dimensions, I edited the project adding some pics and comments with dimensions.
    Glad to be helpful in your project!

    Thank you very much! The additional pictures are very helpful, and the dimensions you quoted match what I was trying to guess from the picture. I just got back from measuring a bunch of casters; it looks like a 3-inch wheel (75 mm) is just wide enough for the 30-mm box beam to fit in the caster housing.

    I'm having trouble finding the antenna bracket anywhere. Did you purchase it locally, or online?

    About the antenna bracket, I bought it at a local hardware store, and they apparently don't sell online. I don't know if you have something similar around your place, but check this link: , you may print this and take it to some hardware store or some antenna installer to get clues.

    Thank you! I had posted a Question about this, and user gadget-man pointed me to an alternative:

    It comes with a threaded 3/8" (9.5 mm) hole, which is exactly what the caster uses. Put a jam-nut in between and it'll be solid.

    This is a great idea. I have actually been pondering how to make a hitch and the torsional freedom with the caster is excellent!

    This is great. Thank you for sharing it.