my bike trailer completed Nov 2025


That's the trailer, hitched up to my old errand bike (which I call my "junker").  (There are lots more pictures below.)  Since it's unusual, I get lots of looks (of the good kind) as I go by.  Men have said it gives them nostalgic memories of the old "woody" station wagons that looked like woodgrain on the sides, or of wooden boats.

In 1992, my car's throwout bearing went out, and I shrugged and said, "I don't need a car.  I'll go back to riding bike" (like I did before my future wife came along ten years earlier when I was 22 and I couldn't take her on a date on my bike, so I bought my first car).  (We had another car which she was driving; so we would not be totally without a car.)  I started building a bike trailer, using 1/4" and 1/8" plywood, to be able to carry things too big to normally carry on a bike, including my cello.  Well, soon my parents gave us another car, which kind of defeated the purpose of seeing if I could go car-free, and progress on the bike trailer stopped.

In the fall of 2025, I picked up the project again, since I got laid off.  Now it's partly for prepping, although I might also like to break my dependence on my vehicle, since California has nearly quadrupled my yearly vehicle license fee in recent years (when it's supposed to go down, not up, as it gets older), and there's the smog testing which also costs money, and our insurance premium went up 80% in six months because of California regulations, even for the same vehicles, and no accidents or tickets!

The trailer has 5½ cubic feet of internal space, and more stuff could be strapped on top of its removable cover if necessary, like on a roof rack of a car.  It has 10" solid-rubber tires, and has springs to avoid damage from hitting bumps hard.  It's designed to be aerodynamic.  The bottom is more or less waterproof, so if we had to go through water that's several inches deep, it'd be like a boat, and although the wheels and suspension parts would get submerged, the insides should stay dry.  The top is water-resistant for light rain; but if I really needed it waterproof, I'd have to tape around the cover, or make a large, removable thing with an elastic band, like a ladies' shower cap.  The whole thing, unloaded, weighs 25 pounds, a couple of pounds less than the bike it's shown hitched up to.

The biggest challenges were making a hitch that pivots in every axis where the tongue attaches at the bike's rear axle (which makes for much better handling than other attachment points do), and making the aerodynamic nose.  Another challenge was getting a stiff-enough tongue, and bending the tube into the right shape.  My first efforts were way too flexy, and the trailer had unacceptable yaw, pitch, and roll.  (The reason for the roll was that it had springs, and no anti-sway bar.  The springs were not much of a challenge, since I had just done more or less the same thing when I made a wooden sidewalk car for our kids, which weighed three times as much.)

This picture was taken before I figured out how to make the aero nose, and also shows my first effort at a tongue, which was much too flexy:

The wood is all painted with marine varnish, made for boats.  I coated it before assembly, so the hidden edges have the coating too.  The back, floor, and two surfaces of the wheel wells are 1/4" plywood, and the rest of the plywood is 1/8".

These two show the suspension, which is like Ford pickups' Twin-I Beam:



In this last one above, you can see a little bit of the coil spring which goes over a 1" dowel and supports the trailer at the inside top of the wheel well.  As the spring compresses, the dowel goes up through a hole in the wood at the top of the wheel well.

Holding the whole thing down to the width of my shoulders and elbows as I ride, I wanted maximum inside width and at the same time, widest wheel stance, and keep a smooth outer surface over the wheels for reduced wind resistance, not open fenders.

The wheels shown above are back on the wooden sidewalk car mentioned further up, which now is being used for the grandkids.  They'll outgrow it soon, but I didn't want to wait, so I bought two more wheels.  The only narrow 10" wheels with ball bearings have become ridiculously expensive, so I got these others made for things like lawn mowers, from Harbor Freight:

They're disappointingly heavy, at 5½ pounds for the pair!  They are rated for 150 pounds each though, 300 for the pair, and I imagine it'd be a lot more with springs (which I have); so they should be plenty durable.  I'll definitely be going a lot faster than you would with a lawn mower or wheelbarrow, but the loading on them will be minimal compared to their rating.  I greased the bolts that go through as axles with silicone grease made for rubber O-rings and plastic parts, thinking that regular petroleum-based grease might eventually make the plastic crack. 

Here's one of the wheels, mounted:

The bolts are smooth at the end with the head, so the wheels are not riding on threads.  The nuts have the nylon inserts so you can set the position and they'll stay, without having to tighten them against anything.

I put dividers inside which, when in the up position, can keep the load from shifting around.  There are also eyelets here and there to tie things down when needed.  Here's the rear divider, in the up position:

It rotates up and down on hinges at the floor.  Hinges connected to the tops of the wheel wells can be rotated out to clip the top of the divider to with binder clips.  When these hinges are not in use, they rotate over against the wheel wells, out of the way.  The picture below shows the two dividers in the down position (for carrying longer things), and you can see the front top hinges still in the 'out' position, whereas the top rear hinges are rotated against the wheel wells:

(You can also see the large fender washers, with black rubber under them, at the tops of the suspension towers.  These will go up further above the wood as the wheels get pushed up into the fender wells on their springs.  The dowels that the springs fit over go in and out of 1" holes in the wood there at the top of the fender wells.  The large fender washers keep the dowels from coming all the way out the 1" holes when the springs are completely uncompressed.)

The top (and nose cone) is Coroplast.  There are 1/4" square slats running across underneath to give strength, which lean on similar wood strips running down the inside tops of the side walls.  On the top, three such pieces run down the length, partly to keep anything you strap on top from sliding around, and the orientation of these slats will prevent unnecessary wind resistance when there's nothing else up there.  The slats underneath are visible in the first picture at the top of this page.  The ones on the top, running down the length, can be seen here.  They hang over the front and rear of the cover, to lean on trailer body parts:

(There are small screw eyes at various places on the edges to tie things down to.)

The cover is on lift-off hinges, so it can be quickly removed and re-installed.

With this construction of cover, the means to keep it closed was a bit of a challenge.  I ended up with small screw hooks and small bungee cords that are much thinner and lighter than the common ones, being 10" long and hardly over 1/8" diameter.  They came in a small plastic jar of 20 from Home Depot, "HDX" brand, model #56055.

The lower hooks are open at the bottom, and it's quick to pull the bungee cords down over the open end to release the cover.  It's visible in the "unlatched" (for lack of a better term) position in the last previous picture above.

Now about the fairing / nosecone:  The following shows my third (or is it fourth?!) idea.  I formed kind of a curved X with thick aluminum wire, made loops in it to screw down to the wood, and then put Coroplast over it, and tied it to the wire with lots of zip ties.  It worked out ok, except that the seam is not as smooth as I had hoped.  Taping improved that somewhat, using tape that can be stretched into slightly complex curves.  It seems so strong that I think if it were possible to pull the wire out after the zip-tying, it would still work fine.  Here's a close-up, taken before taping:

...and backing off a bit:

...and the inside:

Unfortunately I creased the Coroplast in a couple of places.  It'll have to do.  Since the nose doesn't have a flat floor, I might decide to put a removable shelf inside there.  (The aluminum tube used for the tongue shown in the picture was a smaller-diameter one, before the final 1.2" one which finally proved to be adequately stiff.)

As mentioned above, my initial efforts for the tongue were too flimsy.  I started with aluminum tubing with an OD of a little under 3/4", and did the bend with our son's conduit bender.  Before I even rode it, I could tell it wouldn't do; so I tried again, with 7/8" OD tubing.  In the first test ride, it was so-so above 15mph, but at lower speeds the trailer had excessive yaw, pitch, and roll.  I got a 1.2" OD aluminum tube, but could not find a 1¼" conduit bender; so my idea was to bend it over a 24" steel bicycle wheel with no tire on it.  Nope.  I couldn't.  The tube was way too stiff.  I thought I'd have to get a 1" and a 7/8", and put the 7/8" inside the 1", and bend them together, with a 1" bender.  But then I found that the 1.2" tube did fit in the 1" bender.  The first time I tried, I didn't do it right, and I ruined it; but then I realized the tube was long enough to just cut that part off and try again, without having to buy another tube. The result is shown below:

There's only very minor wrinkling at the inside of the curve.

That leads me to the hitch.  This is at least the third idea, as the first two didn't work out well.  Here it is, unhooked:

Many of the trailer parts are assembled with blue LocTite on the threads so things cannot loosen on their own.  The thing with the four nuts on it is a screw eye, with an aluminum spacer pressed into it (I had to put the spacer on a bolt, in the drill, to file it down to size), and a piece of brass tubing inside of that, to take up the slop on the pin of the part that's on the bike, shown below.  The goop is JB Weld.  Each pair of nuts shown above is tightened against each other, with no pressure on the hinge, so the screw eye can rotate in the hole I drilled in the middle of the hinge.  So there you have the three axes of rotation.

This shows it on the bike:

and more close up:

This is the gizmo I bought on eBay to clamp to the bike's left-rear dropout with the skewer, to hitch to:

Do a search for something like "bike trailer hitch coupler attachment for Burley bicycle trailers 12.2mm" on eBay.  Obviously a longer skewer is needed, to accommodate the extra 5mm or so.  I got a really long skewer from Old Man Mountain, but what I really should get is a mountain-bike skewer, which is for 135mm dropout spacing, 5mm more than road bikes' 130mm standard spacing.

There are small castors at the back, for two purposes: The trailer can be stood up vertically as shown near the top, and if you use the tongue as a handle, you can wheel the trailer around at an angle kind of like a hand truck.

Also, if you go through a really serious dip when pulling it, the castors will hit the ground rather than the wood hitting it.

For another detail, I added a couple of sets of three hooks to hang these expandable pencil cases made to go in 3-ring binders, to put small things in that you don't want getting lost in a load of other stuff, or small things that might otherwise get crushed.

On the other side of this, closer to the camera but not visible in the picture, a small bungee cord (described above) can hold three water bottles standing up against the side.  Something I should figure out is how to also add a bag for my laptop computer, with a little "give" (even though the trailer has springs).

The back has a big slab of red reflective tape:

I should come up with a way to mount lights on it.

Here are a few more random pictures:

Pulling it on flat ground at a steady speed, I can hardly feel it.  I definitely feel it when "shoving off," ie, when I do that first pedal stroke and then want to get my shoe clipped in on the other side, as the speed doesn't come up as quickly, so I might do a couple turns of the left pedal before getting my right foot in.  I definitely feel it going uphill with the extra weight.  With solid rubber wheels and the wood acting as a sounding board, and no added heavy sound-absorbing material or coatings, it definitely makes a little noise, especially if the road is not very smooth.  (Brand-new pavement is sure nice though!)  My dual-pivot rim brakes are plenty strong so there's no trouble stopping it.

I am tempted now to use what I've learned, to build a second one, better in every way: bigger, lighter, cheaper, perhaps even more functional, and definitely finished super quickly compared to this one.  (I know I should get some miles and experience on this one first though.)  Besides using it for grocery shopping or other load transport, if things ever get bad enough to have to evacuate and we can't do it by car, whether because the roads are clogged or gas becomes unavailable, it'll be good to have an additional bike trailer for one of the sons (in addition to the panniers that normally go on a bike rack).  My wife and I would pull this one on the tandem.

Pardon the poor quality of my cheap $30 Vivitar S126 pocket camera.  I don't use a cell phone, the #1 reason being that cell phones are the prime surveillance device!



posted Nov 22, 2025, page last updated Nov 24, 2025             contact:  Garth Wilson, wilsonminesBdslextremeBcom (replacing the B's with @ and .) (southern California)  No SEO spam!