The uni.5 SH 29er (Blue Shift)

This unicycle has a shiftable uni.5 hub with a 29 inch wheel. I named it Blue Shift. This is for several obvious reasons. It's blue, you can shift it, and Blue Shift is an astronomical term referring to the apparent change in the frequency of the emitted light of an object moving rapidly toward you.

Steve Howard custom built one of his gorgeous color-anodized aluminum frames for me and made special cutouts for the torque arm attachment and some extras to experiment with a tool-less shift scheme in the future. The width matches the uni.5 bearing spacing. It was assembled with hardware that allows it to be shifted from a ratio of 1.5:1 (43.5" wheel equivalent) to 1:1 (29" wheel equivalent) by moving a single socket head 1/4" bolt and a nylon spacer. The bolt head is machined at the base to produce a shoulder bolt for precision alignment and it requires only a 3/16" allen wrench to do the shifting. It takes about 30 seconds to shift from one mode to the other. Steve's frame accommodates an Interloc 27.2mm aluminum seatpost onto which is mounted one of his stainless steel, tiltable Miyata rail adapters. The front handle is one of Steve's Kinport handles.

I had the wheel assembled with one of two uni.5 hubs I had made. The hub had several mild steel components, one of them being the axle. The rim is a Velocity dyad 700c and has a NanoRaptor 29" tire mounted on it. The incredibly strong wheel was built by Jef Michel at BikeSport in Seattle. I started with 5.5" Lasco cranks mounted on it because I had to have aluminum cranks with the soft steel axle. I eventually found some 170mm blue anodized Kookas that are straight and had them triple drilled for different effective lengths. The total weight is 15 pounds even or 6.8 kilograms; about 3/4 of a Coker.

I was only able to ride for about a mile before the axle twisted and bent. This seemed odd because the original 24" uni.5 had already gone 600 miles when I released it at UNICON XI. I had to disassemble the hub and cut the planet cage off of the axle. I made a new axle out of some 17-4PH hardenable stainless steel that Steve told me about. I also shortened it as much as I could. I took 0.85" in length off of the tapers. I welded it to the planet cage and hardened it. The stuff hardens at 900F in an hour and can be air cooled. It was easy. I reassembled the hub with the hardened axle. The large diameter wheel and the fat cross section of the NanoRaptor tire makes it smooth to ride. I easily get it going above the runout speed in 43.5" mode without spinning like crazy.

This is the left side view of Blue Shift.

This is the right side view.

This shows the shoulder bolt and the nylon spacer (white) locking the torque arm to the hub in 29" mode, or 1:1 ratio, direct drive.

This shows the hub with the hardware locking the torque arm to the frame in 43.5" mode, or 1.5:1 ratio which is the high gear.

Photos by Greg Harper