Building The Worlds Tallest Unicycle @ 115+ Feet

A guy is filming a documentary on my crazy weird lifestyle of street performing, traveling the world and doing the #vanlife. He flew out to film some of my sprinter van build last week and got lots of good footage…and will be following me around this summer as I perform. He’s looking at a 30-90 minute film.

Anyways, he wants the film to end with a bang and I had told him how I always wanted to break the world record for the tallest unicycle…it’s been on my bucket list for along time now. He said he’ll find a sponsor to build it so now I’m trying to figure out a way to build it! Anyone have any suggestions on who I might contact besides Sem Abrahams who holds the current record at 114.8 feet?

The key to building I think is to build it as light as possible…because I’m assuming it’s nearly impossible to control if the unicycle is super heavy and I’m sitting on top and not that heavy. A chain is so heavy that it would be nice to get rid of it and either use a drive shaft if it would be lighter or some type of laser system with a motor at the bottom/top so when I moved the cranks it would move the wheel simultaneously… Have no idea if this would work or if it’s possible to be made? Would love to get thoughts on this.


Sweet! I think a drive shaft would be heavier than a chain. A remote motor system would be really cool…that’d be a novel idea for a chainless giraffe in general.

Would a non directly driven giraffe count for the world record?

Very cool idea though

Just thinking out loud – a rotary shaft encoder on the cranks with a stepper motor built into the wheel would seem a simple way as a first cut – I don’t know much about large stepper motors though.

I wonder if the driveshaft can be a structural member itself

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If you consider a shaft drive, a hollow tube would be light and handle the torque if it had a larger diameter, and if bearinged properly could be a structural member too Mr. Bacon.


And what about the Unicycle Factory handcrafter of giraffes? There are several classical sizes documented on this forum (including a documentary I think).
I would assume that he would have valuable expertise to lean on for such endeavor (if he is interested by the challenge :wink: ).

Sem and Tom are a good point to start.

As for a drive-by-wire setup, i doubt that this thing will be any easier to ride. Pedaling force will be totally independent from the movement of the wheel and the giraffe itself.

I think the drive by wire system sounds best. I’m just thinking of the force necessary to counteract the momentum of a 115’+ chain or driveshaft. You could probably easily do a prototype that doesn’t actually require pedaling but merely controls the speed forward or backwards by crank position. So long as you’re the one doing the balancing, I don’t think an electric motor is cheating on such an unusual vehicle. From a purists perspective, some form of cheating is just inherent when you’re riding something like this as no one is going to freemount one or ride it without a tether and safety harness.

Carbon fiber should probably be the build material.

Hope you have deep pockets as it sounds quite pricey.

I just watched sem on YouTube. I am curious to why he is using such a small wheel? Any insight?

You might try Kriewall Enterprises, they built Sem Abrahams’ 114.8 ft one and maybe there is a good chance they could make one just a little taller.
From here.


You’re taller than Sem. Just buy his and set the seat post up a little higher.


I’m still hoping someone will know why the world record unicycle Sem Abraham’s rode on has what appears to be a wheel no larger than a wheel from a shopping cart.
I’m trying to grasp what the benefits would be.

I can think of a couple advantages of smaller wheel.

  1. It puts less stress on the frame because of the slow speed. A larger wheel could could be accelerated faster and with the frame 115’ tall that would put a lot of stress on the frame just to keep it straight.
  2. With the tall uni there is no need for larger corrections and small wheel would make it easier to pedal and put less stress on the whole drive train.