How to Build a Car Tire Unicycle

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Introduction: How to Build a Car Tire Unicycle

Wheels Contest 2017

Runner Up in the
Wheels Contest 2017

Where I live, winters can either be a winter wonderland or a muddy mess. In either case it makes it rather difficult to keep up to par on my unicycle riding!! So like any true Maker I decided to try my hand at coming up with a solution to the problem of either not being able to even move because of the snow, or coming inside with a muddy wheel. I wanted something with enough surface area to grip the ground better than an ordinary unicycle, and I wanted something that I didn't care about leaving outside. This is what I came up with! Granted its far from perfect. I was going for a quick and easy one day build. I have future plans to possibly power it using an electric motor in a future Instructable. So stay tuned for more on this project!

Enough with the introduction though. lets get straight to the build!

Step 1: The Basics.

A unicycle is a VERY simple vehicle consisting of one wheel, a frame, a seat, some pedals, and some bearings. This was built entirely from garbage I had laying around, so again it is definitely not perfect, but all in all I am still quite happy with it. Here's what I had laying around for this project.

Materials:

1"x1" square steel tubing.

6" by 1/4" steel flat bar.

A truck tire.

Some parts cut from an old bike frame.

A unicycle seat.

Two 1" pillow blocks.

1/8" thick sheet metal.

2"x2" square steel tubing.

And some 1" steel shaft.

This is somewhat over engineered for the purpose of looks, so feel free to downsize any of the parts.

Step 2: The Wheel Hub.

To make the wheel hub I used an angle grinder to cut a circle out of the 1/8" sheet metal. My circle was about 6" inches in diameter but it really depends on the size of the wheel you choose. Mark the center of the plate on both sides with a ruler, then use something the same diameter as the shaft to mark where to weld it on. Next I placed the plate center on the lug holes and used a sharpie to mark out where each hole needed to go. I used a 3/8" drill bit and bolts to secure it. To get the correct length on either side of the hub (because the attachment point is not in the center of the rim) I placed a board across the side of the tire, and measured the distance from the lug holes to the edge of the board. Do that on either side. From there we need to add the depth of the pillow block, plus the 1/4" flat bar, and leave about 3/4" sticking out for the pedals to attach to.

Step 3: The Frame.

The frame was quite simple to put together. I started by cutting the pieces of tubing to the correct lengths with an angle grinder. Now, I already had the pillow blocks and steel plates to attach them to from a previous project so that saved me quite a lot of time. This step is completely dependent on the materials you choose for your frame design, so I think you can get a pretty good idea of how I designed it just by looking at the frame. Also, Its worth noting that I built the side forks and slid them onto the shaft BEFORE attaching the piece of 2" tubing across the top. Let's just say that taking this apart would be possible, but not enjoyable haha,

Step 4: Pedals and Seat Post.

I have quite a few old bike frames lying around so coming up with the seat post and the pedal cranks was quite easy. I went the easy route and decided to just weld the cranks straight to the ends of the 1" shaft. Its quick and dirty. but it was effective lol.

Step 5: Video.

Here it is in action!

Step 6: In Conclusion.

That's pretty much all there is to it! The final product weighs about 75lbs. Like I said, this was just a quick project that I threw together out of junk I had lying around. Everything should be quite easy to round up with the exception of the unicycle seat. But those can be purchased relatively inexpensively online or possibly at a bike shop. Next step, learning to ride the thing!! I'll be the first to admit that this thing is NOT the easiest to ride, but it is very possible. I think with a slight assist from an electric motor, this thing would be a blast!

I really hope you enjoyed this Instructable, and I hope you gained some inspiration to maybe try this project out and improve upon it for yourself. If you have any questions or comments please let me know. Thank you for reading!

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    2 Questions

    Yeah, that about sums it up. In its past life, this tire was holding down hay tarps for many many years. Unfortunately, changing the wheel would mean cutting off the pedals, making a new shaft, and making a new hub. To me its not really worth the effort to change. Its ridable enough haha. Thank you for the question!

    Did you use whatever tire you had available because it was basically free? If you come across a 'space saver tire' do you think the lower amount of starting and stopping force required would be worth the effort to change-over?

    12 Comments

    Cool project. Looks like riding at at least in the forward and back direction is quite easy. Steering does not look as easy. Can you ride further then the video shows and steer where you want? Can you ride in figure 8's?
    Maybe a little most speed would help the gyroscopic effect of the heavy wheel and just leaning to one side or the other would assist in steering.

    Its really not too bad. Getting started is the hard part lol. Steering isn't too bad on a flat surface, but the road is slightly slanted on the left side. The wide surface area makes the wheel want to follow that contour of the ground with raises the chance of tipping. It takes a lot of concentration to ride haha. And yes! Speed does help a lot!

    Great idea, I often wanted to add a internal gyroscope unicycle wheel inside such that the it would stand up all by itself. If you spin a bike wheel and hold it by one axial it will remain in the vertical while turning. That is why a two wheeled bike is easy to ride. With the proper gyroscopic motion the bike would stand up by it self and Grandma could ride it. Just a thought. Oh ya, you would win the contest with such an arrangement.

    That thought actually crossed my mind! I have seen mini tightrope rolling robots use that same principal. The only problem I see is having an effective spinning gyroscope in such a small space confinement. If you attempt it I would love to see the results! Thank you for the comment!

    I guess you can call it self balancing too! Great idea!

    Looks pretty post-apocalyptic, enough to make Mad Max proud :).

    Somehow I imagine the Mad Max movies would be a lot less interesting if they were all on these haha. Thanks for the comment!

    I salute your terrific use of old, rusty and forgotten materials. Looks like a fun ride.

    Well thanks you! :) Building out of what most people call "garbage" is actually one of my favorite things to do!