Building a Bike Cargo Trailer

I've been moithering my other half for a bike trailer for a while now, and he finally decided that he was going to build me one.  We have a couple of crates in fairly standard sizes which are easy to replace if necessary, so he wanted to design a light frame to carry them, with wheels suitable for carrying weight on our rough tracks.  He found a suitable pair of wheels, fitted with bearings, and a supply of 20mm steel tubing that fitted them perfectly and was strong enough to make the axle, the frame and the tow-bar.  Then started to fiddle about to see how they might all fit together.



He's pinned a bit of tubing into a wheel to create an axle, choosing the appropriate width to fit both crates, and is starting to get the frame sized up.



We drilled a few holes and then he started to bolt the frame together.



He bolted the axle on and then started on the tow bar.  There's a diagonal brace to keep the thing in shape.



We fitted the wheels into place.



The heads of the bolts stick up a bit, and we thought it might prove to be a problem in case it damaged the underside of the crate, but it turned out not to be a problem.



Time to figure out the hitch, which has to fit on here somehow.



It's gonna need the tow bar to be shaped a bit, and we don't have a pipe-bender so it's going to have to be joined.



This should allow for a bit of movement in the trailer without it tipping the bike over.  



And it's starting to look like a real trailer!  It still needs a lick of paint and some braces to support the angles in the tow bar, then I can take it for a test ride.



The test track was a bit bumpy, and I soon realised that we needed locking nuts to hold the bolts in place.  We'd just used ordinary ones in case we needed to alter anything.  My other half came to the rescue with his spanners and a pack of lock-nuts and soon put the tow bar back together again.



And here's the finished trailer, being loaded up with pine cones as winter kindling.  I managed to lose half of them on the way home as they bounced out going over all the bumps, so in future they'll be inside a large bag and held down with a cargo net.

I hope some of you are inspired to make something similar!

That will come in handy. Nice job

This is soooo cute! What a handy idea. I want to make one. I already have a crate and am thinking it shouldn't be too hard to find tubing and wheels.  Thank you for sharing this!

I'm really close to getting mine finished. Hopefully tomorrow there will be some testing and pictures.

It's a single 20" (iso 406) wheel, plastic tub that should hopefully make maintenance days on site much easier.

So... here it is.



I'm happy with the mount.





There's a thrust bearing above and below the attachment point (black bit). Double nylocs is a bit odd but it sets the adjustment on the bearing.



The two bolts on the ends don't take any of the force, they just stop it sliding sideways. The stainless box section is wedged between the cross pieces on the rack.

This mount is the second version.



The first mount fitted across the rack and twisted under load.

As for the trailer itself..

It worked well enough for a few potatoes a box of cereal and a tin of beans, it didn't cope well with about 25kgs of nails.



The weak point is how close together the eyebolts are.



The plastic deforms and the connecting rod twists.


And if you're interested, here's the way the wheel is mounted.

It's useful for us to think about how much weight is too much. Also, what design can we probably make fairly easily.  Thanks for showing us the limits of certain designs. Some people just want to brag about how great they are.  This post shows us advantages and disadvantages of different ways of making the trailer.
John S
PDX OR