Photo Feature
1985 RZ500 - NAKED!

Owner: George Nolan, Indianapolis, IN USA

Note: All photos are links to a larger image

I acquired this RZ500 in 1991. It is a very early model, serial number 128 (101 was the first production model). Unfortunately, it was in poor condition when I got it. The bodywork was in tatters, the tires were bald, and it was filthy. It even had bondo covering dents in the lower exhaust pipes! During the next few months I did a clean-up and overhaul, including new pistons & rings (the cylinder bores were still within spec), Nikon exhaust pipes and Airtech seat and fairing. After this rebuild, I rode the bike for a couple of years. However, I wasn't happy with the looks of the bike. I've always liked looking at the mechanical bits on motorcycles, but the full fairing covered up all of the neat parts.

I disassembled the bike again, and made plans for the next iteration. I've always admired the style of the Ducati Monster, which blends road racer performance with a naked bike look. I decided that was what I wanted the RZ to look like. Merely removing the fairing didn't cut it, there were too many things bolted to the frame and buried beneath the fairing that needed attention.

I started by relocating the electrical parts (power valve control, CDI box, ignition coils and rectifier/regulator) onto a plate mounted under the tank, in the area where the airbox originally was. I used Wyn Belarusky's air filter kit to eliminate the stock airbox components (I designed and CNC machined new outer covers, since they were so visible). On the bottom side of the plate are the ignition switch, choke lever, fuel petcock and the horn. Brackets were welded onto the frame for the oil tank, electrical panel, and rear bodywork. All of the unused brackets were removed, and unused mounting holes were welded shut. An aluminum oil tank was fabricated to fit under the seat, between the top pipes (it holds 1.5 quarts of Motul 600 2T oil). I also made a small battery box for the 12v 1.3A battery.

The stock RZ swingarm has an aluminum brace welded to it, along with a bracket for the rear caliper. The brace provides a convenient mount for a carbon fiber Suzuki GSXR750 hugger fender (Carbon Works). The rear wheel is from a Suzuki GSXR 1000, tire is a Michelin Pilot Sport, 180-55 ZR 17. The wheel and sprocket carrier were machined to correct the sprocket alignment. I converted to a 520 chain, to save a little weight. The rear sprocket is 42 teeth, the front is 16. With the change in wheel circumference, this combination is very close to stock gearing. (Sprocket Specialties).

Since I wasn't going to use the stock rear footpeg mounts, the original mounting brackets for the lower Nikon pipes were removed and re-located. The upper pipes were unchanged.

The front fork and wheel are from a 1992 Suzuki GSXR 750. The Yamaha stem was modified and installed into the Suzuki lower fork clamp. I designed and CNC machined the top clamp and handlebar clamps from billet 7075 aluminum. The clamps hold a K&N Superbike tubular handlebar. A Nissin remote reservoir master cylinder and a universal dirt bike clutch lever are used. The stock throttle housing was modified to incorporate the headlight high-low beam switch and the horn button. The entire left hand switch was eliminated. The front fender is a carbon fiber GSXR 750 from Carbon Works.

Both the headlight and tail light are from a Buell. The gages were purchased from SPA Technique. I use a 12,000 rpm analog tachometer that incorporates a digital speedometer/odometer (driven by a magnetic sensor off of the front wheel) and a digital dual gage, which shows water temperature and voltage. The instrument panel and headlight brackets are fabricated out of 6061 aluminum.

I designed and CNC machined the footpeg brackets, to eliminate the rear peg mounts. Both sides use the stock pegs and levers. The rear brake master cylinder is from some Yamaha (I found it at a swap meet, and have no idea what it originally fit). The reservoir is from a Honda XR400.

The rear bodywork is unique. I started with hand laid fiberglass. When I had the shape I wanted, I took the fiberglass parts to EG Composites. (That's one of the benefits of living in Indianapolis, we have a lot of race car fabrication shops in the area). They made molds from my originals, and reproduced both side covers and the rear cowl in carbon fiber. The seat is also hand made, from a fabricated aluminum pan and seat foam from an old Kawasaki seat. The seat was upholstered by Sargent Cycle Products. Both the instrument cover and the radiator covers are hand laid fiberglass.

After the initial assembly, the bike was disassembled again for the final time. The seat was sent to Sargent, the frame and wheels went to Indy Powder Coating, and all of the steel nuts and bolts went to Commercial Plating for electroless nickel plating. I sent the rear shock to Fox for a rebuild. The bodywork went to Billy Jay, who applied the yellow paint. The stripes are designed to show the carbon fiber weave. During the time when the rest of the bike was out of my hands, I cleaned up and painted the engine. The engine is stock, except for modified reed cages and carbon fiber reeds.

Because I had completely assembled the bike earlier, the assembly went very smooth. I spent a lot of time on the wiring harness, as it had to be completely re-done because of all the relocated components. This was truly a pain.

The bike was finished on the weekend before Daytona Speed Week (March, '02). Unfortunately, there was snow on the ground and I wasn't able to test it until Thursday, the day we were loading up to go south for Daytona. During the week, I repaired a few little problems (coolant leaks, cable routing, etc). Although the carburetors were a bit off, I still rode about 300 miles during the week at Daytona without problems.

Have any questions on the production of this bike?
E-mail George Nolan here.

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