I am proud of my first successful engineering project of building a 26” ultimate wheel.
I did this at no cost using components from a bicycle I scavenged from a skip and bits and pieces lying around the house and the workplace.
The ultimate wheel is made by shortened crank technology embedded using bolts and metal plates within a wooden disc that has a bicycle rim screwed to the circumference.
Photo of parts needed.
Specification
A. Cranks *2: left & right, aluminium, shortened, 300mm pedal pitch = 150mm virtual crank length (from bicycle)
B. Pedals *2: left & right, 9/16” diameter (from bicycle)
C. Rim: 26” diameter (from bicycle)
D. Tyre: 26” diameter, 1.75" wide, very worn (from bicycle)
E. Inner tube: 26” diameter (from bicycle)
F. Rim tape: 26” diameter (from bicycle)
G. Ply wood: ¾” wide, painted black (lying around house)
H. Screws *32: for wood (lying around house)
I. Metal plates *4: 1.56mm thick aluminium, 0.15m * 0.15m (acquired from workplace)
J. Bolts *12: M8, 0.04m long (acquired from workplace)
J. Nuts *12: M8 (acquired from workplace)
K. Washers *41: M8 (acquired from workplace)
Weight ~ 4.5kg
Photo from side of completed ultimate wheel.
Photo from above of completed ultimate wheel. This shows the narrow profile and very low q-factor of the virtual cranks.
Photo proof of ultimate wheel successfully bearing weight.
This footage was recorded after just under 2.5 hours of learning; I was pleasantly surprised by my progress, as I had heard that an ultimate wheel is really difficult, so I had low expectations. After a total of 5 hours of learning; I can free mount fairly consistently, regularly ride nearly 30 meters, and also ride down kerbs. I next desire to learn to ride backwards then idle. Constructive criticism and tips on riding the ultimate wheel are welcome.
After a few practices I had to make some modifications to the wheel: reinforce the metal plating with additional plates (total thickness of plating is now 4.2mm) to limit them bending and also cover the bolt ends with plastic to prevent my trousers being shredded.
The design of my ultimate wheel was inspired by this guide and a couple of photos (at bottom of page). If you are interested in building an ultimate wheel similar to this, let me know so I can give you advice on how to overcome the technical problems; such as getting the wood perfectly round, and getting the pedals perpendicular.
I got my interest in the ultimate wheel from Brian Mackenzie’s
, and I am now in the process of building a 36" ultimate wheel based on this, although this is proving more complicated than I originally anticipated. Does anyone have a 36” tyre they are willing to sell me cheaply for this worthy cause? The cheapest tyre I can find is £60 new from Unicycle.com which is rather expensive given an entire new 28" ultimate wheel is £94.
Photo of my current and ever increasing unicycle collection.
