I have now finished the unicycle I really wanted to build. This one is on a shiftable uni.5 hub with a 29 inch wheel. I started out calling it the uni.5 SH 29er because it was descriptive. It was also cumbersome and impersonal. I recently changed (perhaps upgraded) the name to 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. Some fellow riders have also suggested that blue is the color of the language I use and the bruises that form when I fall off at high speed.

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 seat is a new version (inferior) Miyata with an airseat conversion. The cover is a ReeCycle. The front handle is one of Steve's Kinport handles. I had to keep the Miyata rear bumper on because it's, well, blue.

I had the wheel assembled with the second uni.5 hub 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'd really like to get some blue anodized Kookas that are straight and the right length (5 or 5.5") but nothing like that is available that I know of. The pedals are blue Wellgos because, well, they're blue. 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 as recommended by Dustin Kelm ( Unicycling Productions ). 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. I also installed the lowest "Q" cranks I could find since I could use steel now. As it turned out I didn't have to use steel cranks. The ever-resourceful Amy Drummond of unicycle.com hooked me up with some 5.5" (140mm) Doteks which are almost completely flat AND they're aluminum alloy. I chose the 140mm cranks so that they would be smoother (shorter) to pedal and to start in the right range for mechanical advantage. In 43.5" mode the 140mm cranks provide substantially LESS mechanical advantage than the standard 150mm (6") cranks on a 36" wheel (Coker). The payoff is that the bigger wheel means more speed and the shorter cranks mean more stability at high cadence. In 29" mode, the 140mm cranks offer substantially MORE mechanical advantage than the stock Coker setup. So I can have either a respectable hill climber or a screaming roadster. There are additional photos of the Blue Shift and some short videos of me riding it at the unicyclist.com photo galleries .

The new unicycle is unbelievably fast. The large diameter wheel and the fat cross section of the NanoRaptor tire makes it smoother to ride than the uni.5 24" version. I easily get it going above the runout speed in 43.5" mode without spinning like crazy. It will also climb hills in 29" mode effortlessly. For me, it is faster than a Coker in high gear and climbs much more easily in low gear. And it is strikingly attractive as well.
 
 

This is the left side view of Blue Shift, the uni.5 SH 29er. Sweet little package, eh?	This is the right side view. Still with the Lascos and long, soft steel axle in the side views.
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