Friday, October 19, 2018

A Trailer Project

Wow - it's been a while. Sorry about that, folks.

Not that this comes close to explaining the long gap in posts, but I recently picked up a bike-related project that readers might find reasonably interesting: converting a Burley trailer into a flatbed cargo hauler.

When my kids were small, I had a pretty nice Burley trailer that we got a lot of enjoyment from. When the kids outgrew it, I sold it to clear some space in my garage. Some time later, I found myself regretting that decision. Even though I wasn't using it for the kids any longer, it occurred to me that I could have used it for other purposes, like carrying groceries, etc. I like to run errands by bicycle whenever possible, including grocery shopping - but I'd find that there were limits to how much I could carry on the bike conveniently and easily. I often take big water jugs to our market to refill with filtered drinking water - and those really just can't be carried easily on a bike. A trailer would be great for that kind of thing.

To that end, I had been searching around for another trailer that I could hopefully get for minimum investment. I suppose it didn't necessarily have to be a Burley, but I've found that they are built well and last a good, long time, and I generally like the hitch design which is quite secure but also easy to attach to almost any bike (as long as it doesn't have disc brakes). The problem (at least for bargain hunters) is that they also hold their value better than most other trailer brands. Checking garage and estate sales turned up lots of cheap knockoffs from big department stores like Target and Walmart that I wasn't particularly interested in. Checking eBay and Craigslist often turned up used Burleys selling for $150 - $200 - way more than I wanted for this project.

Eventually I found one for sale locally on Craigslist for $50. It looked pretty well trashed, but given my intentions, I thought it was worth a closer look. It turned out that the frame, hitch, and wheels were actually in fine shape, but the fabric covering it all was a horrible wreck. Apparently it spent a lot of time in a barn where mice had taken residence in it. It was filthy and stank, the fabric was chewed and stained, and it was so badly aged that one could poke their finger right through it and it would just tear. For what I was after, though, it was just the ticket. I offered the guy $40 and he accepted.

When I got it home, the first thing I did was to attack the fabric - cutting it all away from the aluminum frame. All of it went straight into the trash before I'd even consider bringing the rest of the trailer into my basement.

Here you can get a pretty clear view of just how horrible the fabric covering on this thing had gotten. It was totally unsalvageable.
Here's the frame minus its fabric coverings. 
This particular model of Burley trailer was an older one - definitely an earlier-generation design from the one that I had for my kids. The guy I bought it from told me that his youngest kid is now a young man in his 20s which gives a little clue to the age. But I think that the particular design was ideally suited to my plan - to turn the trailer into a flatbed cargo hauler.

With the fabric removed, my next step was removing the upright brackets of the framework - that is, all the parts that form the "canopy" of the carriage. I could have just unbolted the upper rails from the plastic brackets, but that would still have left the brackets jutting upward, getting in the way and looking out of place. Although it would make my conversion impossible to undo, I took my reciprocating saw (aka "Sawzall" - I just love that name. Classic American advertising kitsch. "It saws all"). I had some shortly-lived qualms about making such drastic changes, but I had to remind myself that there was no way that I or anybody else was going to attempt to undo what I'd done. With the fabric covering left unsalvageable, finding (much less installing) replacement coverings would have been expensive and pointless.
With the brackets cut nearly flush, I now have a relatively flat surface onto which I can attach my flatbed. 
At this point with the wheels off and the canopy sections removed, it's pretty clear what kind of form the finished project will take. Next step is to remove the bolts that are holding the remnants of fabric and straps.
I had considered getting some slats of nice weather-resistant wood to make my flatbed. It would look great and still be practical. I still may do that at some point - but I happened to have a couple sheets of 1/2" plywood on hand, so for now I decided just to use that and keep my investment low.

The plywood top looks decent enough - and utilitarian. I attached it from below using the same types of strap brackets that hold electrical conduit to wall studs. I used my router to remove a bit of material under the top to clear the plastic brackets that I had cut off earlier so the top fits down flush onto the frame.
I put some D-ring hooks on the top for attaching bungee cords. I like the soda crate - I think I need to find another, as the flatbed is easily large enough to hold two. I attached it with a couple of carriage bolts and wing nuts so it can go on or off without tools and in minutes.
I figure there's some real versatility here. Wooden crates can go on/off in minutes. Large, irregular-shaped loads can be bungeed down. I'll have to find a bungee net, too.
There it is, all hooked up. $40 for the trailer, another $7 (or so) worth of random hardware, and a couple pieces of re-cycled plywood - and we're ready to haul.


  1. Smarter move than trying to build own as I did way back in 1980. Tempted to carry too much camping stuff, cameras and tripod tripod. Downhill was exciting to say the least. I was 150 miles from home when part of the hitch broke, thankfully just 20 miles from a railway station to get me home. I still wonder about a trailer and no weight carried on the bike...

    Look forward to reading how you get on with your new toy.

  2. welcome back. I was almost reading to hit delete but decided to give it another week

  3. Interesting conversion. I would be tempted to find a second frame and install it 4” higher and use is as a low fence/tie-down rail. And maybe some full covered guards (bottom of an appropriately-sized plastic bin?) But that’s just getting carried away ...

  4. That's my favorite style of Burley... full axle wheels with cup & cone bearings. The newer trailers have a one-sided axle with cartridge bearings. Yours, while older, is better built and should be able to haul a heavier load. It's also US made in Eugene, OR (even the fabric shell was sewn by the cooperative when this was made... Burley has since been bought out by an investor after some financial problems).

    You can also convert the hitch to one that's semi-permanently attached to your quick release. Some people prefer this convenience but the hitch you have is also very functional and stable (and may be a better choice if you use the trailer somewhat infrequently).

    1. Thanks Jo,

      Went to pick up a Burley trailer and recognized it as the one-sided axle you mention here. Bailed on that exchange and found the full axle instead.

  5. Very nice. You'll prolly want to seal the plywood with something so it doesn't start to delaminate when wet. Or better still you might find a piece of marine plywood which has waterproof glue (or just use it on dry days 😀).

  6. Absolutely add another box - or replace that one with a single longer one. Just like a car trailer, you must consider the nose weight and loading balance. Nose weight should be ~10-20% of the whole trailer assembly when loaded.

    Also your braking technique has to flip - rear wheel braking first. I jackknifed a similar trailer with about 30kg of tools going to a bike fixup - Tried to do a quick stop and the trailer lifted the rear wheel off the ground and pushed it all to the side. That was HIGHLY unpleasant.

    Last thing - have you considered bending the drawbar upward, so the 20" wheels and your ~26" towbike's wheels don't make the bed sit crooked like that? Might help center the load.

    My max trailer weight was about 98 kilos, only a few kilos less than the bike+rider combined. THAT was an interesting ride, and yay for the grannie gear. Without 26/34 I doubt I'd have got over a railway line.

  7. In the spirit of keeping things cheap, you could always make a cargo net from old innertubes you may have lying around (

  8. I did the same thing, but with a different brand of trailer. Half-inch plywood is overkill and unnecessarily. I used steel wire animal fencing-rigid, white, with numerous attachment points for bungees and straps. Refrigerator shelving with work too

  9. Really well done project. I've been thinking of doing something like that for a while, though mine would be narrower, but with two wheels. I hope your next set of blog posts are about dealing with cargo, what works, what doesn't, legality (do you need an orange flag or reflective triangle, and what states aren't friendly of these trailers), panniers vs. this trailer, and so on.

  10. Nice! How will you keep your groceries on the flat bed? I imagine you will strap them down? Did you consider a rail or lip of some kind around the perimeter of the bed to keep things in?

    1. In the last picture you can see one of the wooden crates I can attach to the top with carriage bolts and wing nuts. I have two of them, and they can go on or off in a minute or two. With two of them, I can carry quite a bit. If I have an irregular load, I can leave off the crates and use a cargo net.

  11. Instructables has lots of bike trailer plans.

  12. wow, super close to how I modified a flatbed for my dog. I had sides, a front and rear and it was all zip tied or wired down. not one hole was drilled. about 14 years of bliss with her and not one negative issue with the trailer. but man.....the bottom ply is almost exactly the same. I followed the dish of the wheels and rounded all the edges top and bottom.