SportsterPaul's 1980 Sportster monoshock
My 80 Sportster was mostly built by local welding legend Kenny Puccio. It took the 92 Oakland Bike Show "Best Engineering Award".
I replaced the 7/8 inch bars and controls with the pullbacks. I replaced the dual Del-Orto carbs with a single Mikuni flat slide 40 mm. I took off the tiny battery behind the rear cylinder and installed a front battery box. I removed the beautiful aluminum covers from the front down tubes and over the oil tank. This makes visible the clever mono-shock design. I swapped the brake light from bottom mounted where it would get crushed by the tire to top mounted so I can give rides to ladies. The bike has a stock Sportster lower end with a set of Thunderheads on it. It came with a Franks regulator which failed so I mounted a conventional electronic regulator on the end of the generator. I rewired the bike. Duncan Keller, the noted bike builder, said "Thunderheads made a Sportster a different bike". He was right.
The bike came with aluminum covers on the oil tank and on the front down-tubes. I don't believe in non-functional covers, so I took them off. That way I can see cracks and shorts and leaks before they kill me. The tail light was mounted under the fender, but the rear tire would hit it on full jounce and knock the lens off. I just flipped up to the top and mounted it in the same holes.
The license plate was mounted on the swing arm. It broke off early on so I relocated it to the rear fender, but mounted sideways. That has the added benifit of keeping the rear tire from spraying a strip down my back when I ran over water or oil.
Here is the bike up the San Jose foothills. There was a tiny battery that mounted behind the rear cylinder. The bike is very sensitive to low battery voltage and won't start. One episode and I hung a stadard Sportster XLCH battery on the front. That way the bike takes the same battery as my 1962, 1977, and 1979 Sportsters. You can see why I like Bat's style headlamps, you can hang a helmet over it when the bike is parked, and it suits strapping even more stuff like your jacket and such.
Here is a nice shot of the whale that I found in the middle of an intersection, which I promptly strapped on the back seat.
Here is the monoshock setup Kenny Puccio welded up. All he did was cut the battery tray out of the standard 1979=80 oil tank so the shock can pass through. I don't think he even had to lengthen the swingarm.
The engine mount ties in with the tank mount, something I am not too fond of. The mount broke, probably due to my carrying groceries on top of the tank. That hack weld job is mine, not Kenny's. I have an XLCR tank I am going to put on. I detest fiberglass tanks. They are known to explode when you drop the bike, and this one sprang a leak and caused years of mystery as I tried to get another custom fiberglass tank made, with all the attendant petcock and fuel delivery problems. The aluminum cover on the right side of the oil tank did have an ignition switch, so I mounted a toggle switch right near the coil. Unlike my 1962, where I used 20-gaughe aircraft wiring, on this bike I used 14-gauge house wiring.