Design Your Own Super Slick Bike Trailer and Hitch Using Tinkercad

Today I'm going to show you how to design and build your very own custom super cool bike trailer, using Tinkercad! Depending on what you design, this project could cost you just the price of 12 cups of coffee! That's right folks, just 12 cups... Depending on what you've got lying around in that dark corner of your garage, the corner with the odd smell you can't quite put your finger on, you know the one. If you're anything like me, you've got a pile full of junk you just can't throw away, now is a good time to rummage through that pile, and find some stuff to build a bike trailer!

What does this guide cover?

1. Learn how to design and build a super cool bike trailer to fit your needs exactly!
2. Learn how to make the clever and simple trailer hitching solution I used here. (Skip to step 9 if that's all you need!)

Disclaimer!!

Hopefully, this is obvious; when you do it yourself, whatever happens, you did it to yourself...it's quite literally in the name. This bike trailer is NOT intended to be the caboose for taking your little kiddos on a bike ride to the park. That said, you do you, just don't sue. And yes, I'm a rhyming genius, thank you for noticing ; )

You can skip ahead to figure out your design first.

This guide is meant to help you create your own bike trailer using whatever materials you can get your hands on. Let this list be a starting point to give you an idea of the materials you might need.

Frame: You can build your frame out of just about anything, it could be metal conduit, PVC pipe, wood, etc. I used scrap wood for my frame.

Wheels: You will need some tires to make this thing roll. I got mine off two small bikes I found at a thrift store for super cheap. Using just the front tire off of a scrap bike may be easier as you'll have a clean axel with no sprocket to deal with when mounting.

Wheel mounts: A piece of angle iron will work great for mounting your wheels. You could even repurpose the mount points from the bike you got your tires off of.

Stuff to hold it all together: Wood screws, nuts, bolts, nails, and some wood glue should be all you need here. Just find things that work well with your chosen frame material.

Trailer hitch assembly: The hitch assembly I show in this guide only consists of the following parts:

• A length of 1/2 inch metal conduit. See step 9 to measure out how much you'll need.
• 6 metal sinch straps, size will depend on your bike, mine are 1/2 inch wide and 4 inches long. (Adjustable stainless steel hose/pipe clamp). Can be found at any hardware store.
• A 1/2 inch universal ball joint, with fitting lock nut. You can find these online or at a hardware store for anywhere from 80 cents to 15 dollars (USD).
• 4 inches of 1 inch metal conduit.
• 4 2 inch long 1/4 inch bolts, 8 washers, and 4 lock nuts.
• A 2 inch long 1/2 inch bolt with wing nut, 2 washers, and two 1/4 inch long spacers.

Other Accessories: Whatever else you may need to make this trailer yours.

• Things to help you secure stuff to your trailer, such as bungee cords.
• Paint, to make it look pretty.
• Some reflectors to make it safe. You can scavenge these off of old bikes.

First and foremost, ask yourself why. Why do you need a bike trailer? What are you going to use this trailer for? Do you need it to take your chic to the prom, it could totally do that! How much stuff do you plan on moving with it, and what's that journey going to look like? Will you use it to pick up groceries down the street, or are you pedaling all of your camping gear to a secluded spot in the woods?

Now that you know what you want to do with your super cool bike trailer, it shouldn't be too difficult to determine the design requirements you need to fulfill when designing and building your own version of this trailer. If you need this trailer to go over bumps and rough terrain, you're probably going to need to invest a few more dollars and smart scavenging in order to make this thing strong enough for your purposes.

You've figured out why you want to build a bike trailer, and what you need it to do, now the question is, "how do I get it to do those things?"

If you need your trailer to hold a ton of heavy stuff, you're going to need to focus on making a strong and sturdy frame. If you need it to be fast and lightweight, you're going to want to find ways to reduce the number of materials you use, while still ensuring adequate structural integrity.

Some things to consider when planning these things out:

• If you want to ride this trailer around town, it's probably in your best interest to ensure that the total width of your trailer does not exceed that of a standard sidewalk. Luckily for you, most urban areas are built with a pretty standard area of pedestrian travel ways, you wouldn't want to build your trailer so wide that you can't take it anywhere.
• If you plan to be traveling quickly with your trailer, make certain that you have a way to securely stow away any items you have in your trailer, you don't want stuff flying out and getting lost.
• If you plan on making a long trailer, then shift the wheels further to the rear, just like they would be positioned on a long truck trailer...just don't make it so long and heavy that it becomes impossible to safely ride.

Refer to the "Supplies" section of this Instructable to get an idea of what stuff you may use to build your trailer. Go out and scavenge around for stuff you think will help you meet each of these aspects.

At this point in the design process it's good to get your ideas out on paper, so to speak. 3D Computer Aided Design Software is a fantastic tool for helping us picture the things we are trying to build. There are a lot of 3D CAD tools out there, today I will show you using Tinkercad. You can head on over to tinkercad.com to get started!

Something to keep in mind:

For a project like this, it may not be super important to draw up a perfect and complete 3D model of your design. A 3D model can help you come up with ideas and figure out dimensions. But don't overwhelm yourself trying to make it perfect. The goal is to actually make a cool trailer for your bike, not just spend all your time thinking about making a cool trailer for your bike. Model out a rough sketch for how you want to build this thing, brainstorm what items you have laying around to use in the project, test out a few ideas, and then get to work tinkering in the real world. Refer back to your 3D model when it's time to measure out your wood and fabricate a bracket... When done right, a balance of virtual tinkering and physical tinkering will speed you up and help you get from idea to reality much quicker. You may refer to the pictures above to see my model, and compare it to the real thing, it has some resemblance, but it's not perfect, it didn't need to be. Just have fun and design yourself a bike trailer!

When you first start modeling a design in Tinkercad you will be directed to a blank canvas. You'll want to begin by drawing out a rough idea of your frame. If you haven't used Tinkercad before, play around with it first, and maybe watch a few tutorials until you feel comfortable. It's pretty easy to get started, so don't worry!

You can think of the material you plan to use when making your frame. Let's say you choose wood. If you're going to use 2 inch by 2 inch wood of various lengths, you can recreate that wood in 3D.

1. Locate the cube tool, and place a cube on the canvas.
2. Now you can type in the exact dimensions of your wood.

You can repeat this process for all of the parts of your build. Just move things around, rotate, align, and adjust everything until it looks the way you imagined it in your head.

Some things to consider when determining your dimensions:

The most important aspect of your frame is going to be how, and where the wheels are mounted. Make sure you measure the wheels you plan to use. You'll need to leave enough clearance room on each side of your wheel within the frame, if they are too close to the sides, they won't spin.

If you aren't super comfortable designing the more intricate details of the trailer yet, don't worry, I will cover them in the next steps. I'll show you how to mount the wheels to your frame, and how to build the trailer hitch assembly.

If you have any questions about your design, the folks here at Instructables created a neat little comment section below this guide, post your question there and you might get lucky, it may just get answered...or maybe not...you never know.

Once you have a 3D design of how you want your bike trailer to look, you can begin building it! The cool thing about having a 3D version of the thing you are about to make is that you can always reference it when you're building the actual thing. You can use the 3D dimensions to determine how long to cut the pieces of your frame, and understand which pieces go where!

Begin by cutting out all of the wood for your frame. And remember, measure twice, cut once...and then realize that you measured wrong, and shout your favorite expletive quietly to yourself because you're working on this at 2am and the family is asleep.

When working with wood, it is always best to drill pilot holes before you get your screws in, it will make for a tight strong joint. Additionally, consider lathering a bit of wood glue to each joint before screwing it together, this will help keep the trailer from becoming loose and squeaky over time.

There are two ways to do something, there's the pretty way, and then there's the way that gets the job done and works just fine. I have chosen the latter. I scavenged a length of angle iron, threw it in the drill press with a little oil, and wore through a new hacksaw blade. In the end, I had some brackets to mount my two wheels.

We need to recreate the part of the bike from which you stole your wheels, the dropout at the base of the fork where the axles sit. We do this by creating a bracket consisting of an identical cutout, and some mounting holes.

1. Drill a hole: Make sure you account for the diameter of the wheel axles you will be using. Mine were a 1/2 inch, and therefore I used a matching drill bit for making the axle cutout.
2. Cut out the dropout: When cutting out the section below the hole you just drilled, it doesn't need to be perfect, so long as the hole you drilled before is round, the wheel should slide in and sit snugly.
3. Drill another hole or two: Drill your bracket mounting holes to fit the bolts you will use to secure them to the frame.
4. Put it together: Measure and mark the sides of your frame. It is imperative that both wheels are perfectly aligned with one another and the frame, as to avoid your trailer going off on a journey of its own.

Finally, mount your wheels onto the trailer in the same fashion as you would mount them to a bike. Make sure the axle sits straight in the dropouts.

Now for the fun part, getting this pile of wood and rubber attached to your bike!

This part is all about your exact bike, every bike is a little bit different. Luckily for you this bicycle trailer hitch is simple, and you can definitely get it to work for your bike!

This bike trailer hitch I have created here is quite simple and cheap. Unlike some other DIY trailer hitches, this one mounts directly to your bicycle frame, allowing for more points of contact, therefore creating a very strong solution for hitching a trailer.

Something to keep in mind as you are figuring this out:

When you attach this hitch assembly to your bike, you don't want it to interfere with any moving parts of your bike. Look at the pictures below and think about if you will need to move your hitch further up your bike frame, or if you will need to add any extra bends to allow it to fit around your bike. If you have disc brakes you may need to alter the design more than someone with rim breaks. There is a good chance you will not be able to avoid interfering with your rear derailer cable, bending a piece of scrap sheet metal to create a tunnel for the cable may be necessary. Alternatively, you could run an extra piece of cable sheathing over the part that interferes.

Additionally, my design makes it somewhat difficult to remove the rear bike tire. Adding a few slight bends in the pipe--dodging the axle--would make this problem go away. This problem will be harder to solve if you have quick-release tires, however, I'm sure you can figure it out : )

Refer to the pictures above for this step, you will need to decide on your own exactly how to make this.

Remember, the supplies for this step are listed at the beginning of the Instructable.

The first part we will make is the piece of hardware you'll be installing on your existing bike to allow you to attach a trailer.

1. Calculate your dimensions: the back end of your bike should have four supports connecting the bike frame to the rear wheel. These members are referred to as the "seat stays," the supports going down from the base of your seat to the center of your wheel; and the "chain stays," the lower supports which are close to parallel with the ground.
2. Begin on the right side of your bike (the side with the chain). Locate the spot on your chain stay, roughly 3 inches forward, away from the center of your wheel, towards the front of your bike. With your tape measure, measure from this point, and go up to roughly 1 inch above the point where your tape intersects with the seat stay. Remember this as measurement "a."
3. Next, measure from that same point on the chain stay, straight back to roughly 2 1/2 inches past the back of your rear tire. This is length "b."
4. Take the width of your rear tire, and add about 2 inches. This is "c."
5. Now, solve. a*2 + b*2 + c = the length of conduit you will need to bend to make your trailer hitch.
6. Keep in mind, that this may not work for your bike, so play it by ear and mess around until you’re sure it will work for you. You don't want your trailer hitch assembly to interfere with any function of your bike (i.e. brakes, chain, derailer, or other such functions).
7. Bend your conduit: you're going to go ahead and bend your conduit into the shape pictured above, and you will use the individual measurements you just made to aid you in determining where to bend. Feel free to use a proper pipe bender for this, I did not...you can probably tell by how deformed the bends are in the pictures above.
8. Install the universal ball joint: drill a hole to fit your universal joint into the back of your hitch assembly, slot the joint in, and securely fasten it with a lock nut. You may leave some slop in the joint so it may freely spin within the hole you drilled. Keep in mind, if your conduit is not large enough to hold onto the universal ball joint, you may need to add a secondary piece of pipe, as I did, to ensure a strong connection. This connection is crucial to the proper working and safety of the trailer and trailer hitch.
9. Mount your hitch assembly to your bike: Using metal sinch straps, and optional rubber (you can use an old bike inner-tube) to protect your bike, strap the hitch assembly according to the manner in which you determined it to fit best when you made your measurements, see the picture above for reference. Be careful when positioning the straps on the chain side of your bike, if you put them on correctly, they should not interfere with your chain.

Don't worry if your trailer hitch is not perfectly square or equal on both sides, so long as it mounts securely to your bike frame--with zero interference--the fancy universal ball joint will take care of any minor miss-alignments in your trailer hitch assembly.

You also need to fashion yourself a hitch-point for the trailer.

1. Squish some pipe: Take your 4 inches of 1 inch diameter conduit, stick one inch into a vise, and smash it down flat.
2. Cut some pipe: Take the un-squished end of your conduit and cut 2 inches down the center, perpendicular to the squished direction. Then take those 2 inches and squish them together in the vise.
3. Drill a hitch hole: Drill a hole near the end of the side you squished first, make this hole the same diameter as the hole in the receiving end of your universal ball joint.
4. Drill some mounting holes: Drill 2 holes straight through both parts of the other squished together side of your hitch point. Make these holes according to the bolts you plan to use when securing the hitch-point to your trailer. Separate and flatten out these two sides after you drill the holes.
5. Mount that hitch: Stand your bike up straight and measure from the universal ball joint to the ground. Now take your assembled trailer and position it level with the ground, use the measurement you took to position your trailer-hitch-point at the same height as the hitch assembly on your bike. You may need to adjust this height to better suit your liking.

Now it's time to hitch that hitch and trail your trailer!

Using an appropriately sized bolt and wing nut, you can hook your trailer up to your bike!

Splash on a little paint, double-check your mounts and connection points, and hit the road!

THAT'S IT FOLKS! HAVE YOURSELF A FANTASTIC DAY!