Build Your Own Tow-Along / Bike Box / Cargo Trailer!

Hi there internet!

We’ve been live for a whole day now, and we have had a few (a few–people are actually looking at this website!) people ask how we built our tow-along / bike box / cargo trailer.

So, lo, and behold our…

STEP BY STEP PRODUCTION GUIDE TO MAKING YOUR OWN TOW-ALONG

Caveats: We had some tremendous advantages with building our tow-along:

• We had an old child trailer that we ripped up for its frame,
• One of us lives in a giant former warehouse space that had plenty of room for us to work in,
• That warehouse space happened to be right next to our local and super awesome tool library, the Station North Tool Library, of which we are members. So we were literally able to run next door if we needed more tools and supplies,
• That warehouse space also had a collection of free scrap wood for us to use, laying around.

The supplies you’ll need are down in Step 4, but you’ve got some planning to do before you get there. Without further ado:

STEP 1: Find a Chassis

Since I assume most of y’all aren’t welders or have access to an arc welder, it’s probably easiest to find an old/used child bike trailer and rip off all of the fabric. That’s what we did. So check out your local Craigslist or Freecycle group. Make sure it comes with the attachment for the rear wheel hub of your bike and is in decent shape. Check that the wheels are in good condition and rotate smoothly.

STEP 2: Rip All of the Stuff Off of Said Chassis

Pretty self explanatory. Remove all of the fabric and plastic and whatnot and get the frame completely bare. Consider saving and using some of this fabric as a tarp along the bottom of your container to keep out what your wheels are going to kick up underneath your bike box. Make sure there are no structural problems with the frame.

STEP 3: Plan Your Container

Look at your chassis. How wide of container will fit snugly inside of it? Will you have to build a base on the chassis and then mount a container? Would it be easier / more useful for you to make a wagon? Some options we considered:

1. Building a wagon with mounting spots for another container

2. Buying a large plastic waterproof storage tub and mounting that to the chassis.

3. Mounting one of those plastic bakery tray things directly on to the chassis (we found one behind the warehouse AFTER we discussed this).

4.  Building a wooden / plastic box that will fit inside the chassis.

We went with #4, because we had some free plywood we could recycle. Assuming you’re reading this because you want something like what we made, the rest of this is going to go along with that option.

STEP 4: Upcycle or Go Shopping

Measure your box out exactly. Measure AGAIN. Triple check your measurements. If you’re building a bike trailer you probably can’t afford to buy supplies twice, so be confident with how your box is going to be constructed.

If you’re trying to recycle building materials as much as possible, check with your local affordable housing organisation and see if they sell excess materials (like the ReStore for Habitat for Humanity), artist or living cooperatives that may have raw materials people left behind, or your local salvage or deconstruction resale store (like Baltimore’s very own, super awesome Second Chance). A little research and snooping can save you a lot of money.

For our box, we used the following:

• Decent plywood (if getting second-hand, check for swelling from too much moisture exposure and that any factory cut edges are not damaged)
• 2×1’s for the interior frame (ditto on the quality check above, particularly for warping)
• Water-proof sealing caulk
• Wood screws (don’t get them too long, or you’ll have to get a metal saw and cut off the exposed sharp ends–they just need to be long enough to get through the thickness of your plywood and bite into the 2×1 frame)
• 50- or 80- grit and 150-grit sandpaper
• U-bolts large enough to reach around your chassis frame and grip on to nuts and washers inside the box, and those washers, nuts, brackets, and some rubber washers as well
• Two hinges for the lid (if you’re going to a salvage shop, you can easily find pretty nice or even antique hinges, and this will save you $$$) and some handles
• Some method of securing the lid (we had an old padlock and bought a hasp)
• Weather-proofing foam strips (the ones you use for windows or doors worked well for us, and we found some laying around)
• A water-sealing primer
• Paint or whatever you want to decorate your box (we used black spray paint and just went over everything)

Tools you will need:

• Measuring tape
• Sawhorses
• Saw
• Caulk gun
• Razor blade
• Drill, with drill bits large enough for your u-bolt to fit through and a bit for your screws
• A rubber mallet can come in handy to knock things in to place without messing up your plywood
• Paintbrush

STEP 5: Build Your Box Frames, Base, and Walls

Cut your plywood to the sizes you need with the hand saw like a boss. Try not to cut off the red-painted factory-cut edges as those are the straightest edges you’ll likely have on this box.

Patrick sawing through four sheets of plywood simultaneously like a boss

Cut the 2x1s to their required sizes and screw them together to make 2 rectangles–these are your frames. Remember, plywood has a rough side and a smoother side–you’re going to want the smoother sides to be facing out, so keep that in mind while you’re building the box. Mount the bottom face of your box to one frame. Put the bottom of the box with frame on the floor and (with a helper to keep things lined up) screw the side of the box into the frame you made out of the 2x1s. Then take the second frame and fit it into the opening on the top and secure that with screws. You now have an open bin! Way to go.

STEP 6: Caulk It Up

Make sure your caulk is good and waterproof. You’re going to run it along all of the exposed seams where one piece of wood/plywood meets another. Make sure you get the nose of the caulk gun as far in those seams and cracks as you can and fill it up. Once all of the seams are full, take some more screws and screw the sides of the box more securely into the box frame. With the caulk in between the pieces of wood, the screws will pull the wood closer together and make the caulk seal nice and tight. Let the caulk dry.

STEP 7: Sand It Down

Now that you box frame is built, it’s time to sand it down. Starting with the rougher 80-grit sandpaper, sand the whole thing all over its exposed faces. Once that’s down, sand it again with the finer 150-grit or what have you sandpaper. Take a dry cloth and wipe off all of the dust. If some of the caulk is poking out of the seams and isn’t easily coming off with the sandpaper, take the razor blade and run it along the surface to remove the excess.

Step 8: Prime Time / Paint?

Take out your primer and paintbrush. Cover all of the exposed sides with a good coat of the primer.

Wait 24 hours for the primer coat to dry. Using your finer grit sandpaper, lightly sand the whole thing again. Lightly–you’e not trying to sand off what you just put on it, just smoothing it out. Wipe off the particulate stuff with your dry rag, and apply a second coat. This primer is what is going to protect your box from the elements, so don’t skip out on the second coat of primer! Let it soak into the plywood and dry for 24 hours. Don’t forget to do this to the lid’s smooth side, too, which we haven’t attached yet and is probably hanging out in a corner somewhere.

We mounted the box at this point because we were planning on just spray-painting all over everything, chassis included. If you don’t want to do that, now’s the time to paint/decorate your box. Let it dry for however long your paint says to.

Ken spray-painting the box

STEP 9: Mounting the Box on the Chassis

Man this is getting long. Okay, so now you need to flip your box over, and check out how you’re going to mount it to your chassis. This can vary widely depending on what your frame looks like–ours had these nice shallow U-shaped cross bars that made a perfect spot for us to wedge our box in (which we did with the rubber mallet because it just barely fit–one of those may come in handy for you here).

Flip your chassis over and position it on the bottom of the box so in the position you want it to be in. Keep in mind that you need clearance toward the front of the box for your rear bike wheel, the position of the wheels on the chassis so you can properly balance your box on it, and how much overhang you want off the box. All of these are pretty crucial so take some time to get it properly positioned.

Once you have the chassis where you want it, use your U-bolts as a guide to mark where you need to drill into the box. Drill those holes. Because our chassis’ crossbars were rectangular, we had the U portion of the U-bolt be inside the box (handy as a strapping point for bungee cords) and used brackets to secure the ends of the bolt to the crossbars. Use the rubber washers and some more caulk to make bottom of the box with the parts of the U-bolt sticking out as waterproof as possible.

A mounted box!

You my need to do some touching up with the paint or what have you at this point.

STEP 10: Fit the Lid

Flip your box and chassis back over. Stick your weather stripping all along the outer edges of the top of your box’s side walls and the interior 2×1 frame. This will not only keep your box from slamming shut but will also keep the lid from rattling while you are riding around town. Don’t take off the backing paper from the weather stripping or it will just stick to your box lid weirdly for a while until it gets gunked up.

With the weather stripping cut and put in place, position your box lid on top of the weather stripping and mount it to your trailer with the hinges. Make sure it opens and closes properly and securely. Attach the hasp to your box lid and the handles if you’re feeling fancy.

STEP 11: Test Ride!

Arne testing our bike trailer!

Time to take it for a test ride! Rig up your new bike trailer to your bike and take it for a spin! See how it handles, and take care around turns and whatnot. It’s going to take some getting used to.

Hope this was helpful to someone! Feel free to email us if you have any questions or just to let me know someone read this: info@epiccouriers.com