Honda CR500 Supermoto: A Rider’s First Hot Rod

After 30 years in the saddle, owner Thad Wiley meets Steve Biganski with epic results

Custom license plate
Not sure there’s another license plate like this one. “Yes, sir, street legal,” owner Thad Wiley says.Wiley Collection

“When the other guys were buying cars and motorcycles, I was working and saving. I was a workaholic,” Thad Wiley said. “I’m 70 years old and this is the first hot-rod project vehicle I’ve ever had!”

Wiley specialized in air-conditioning systems for high-rise buildings and later built homes, and it was on a high-rise project that a coworker asked him about motorcycles. Wiley told him he had never ridden.

“After three months of bugging me, I told him I’d buy a bike if he did.” The coworker, who is the original owner of this 1984 CR500, became one of his closest friends and helped launch Wiley’s love of riding. “Man, I was completely hooked. Forty years old and completely hooked.”

The night before we spoke, Wiley had returned from an across-state ride on his Suzuki V-Strom 1000 and also owns a BMW adventure bike. For almost 20 years he raced and rode in the dirt of California and Baja Mexico and at 70 years old is still getting a lot of two-wheeled miles in.

But this is his first hot rod: a 1984 Honda CR500 supermoto two-smoker.

“I bought this CR from my friend for $400 and did a lot of enduro events on it. It’s titled and licensed, but I got a little burned out while I was restoring it; I didn’t know what to do with it. Then I met Scott Holden at the BMW shop and he told me about Steve Biganski.”

Bignasty

Ah, Steve Biganski. I met Steve Biganski at Willow Springs Raceway in the late ’80s when my FZR600’s rear tire went flat in turn 8 and the ensuing sideways drama came within millimeters of taking him and his Aprilia 250 for a wild ride in the not-well-groomed runoff area at about 120 mph. We both survived the incident and a friendship started. At that point I was racing an FZR400, 600, and SRX600, but was “two-stroke curious.”

Steve Biganski
Steve Biganski in 1995 at Daytona with the Zero Gravity TZ250: clean and consistent.Ienatsch Collection

Biganski, through Del Amo Motorsports where he worked, was my path to a Yamaha TZ250. Steve and I teamed at Willow Springs, him building and tuning with me riding, and moved on to AMA 250GP. In seven years of competition my TZ never failed. Well, except when we tried nitrous oxide injection for WERA’s unlimited class—it blew up quite spectacularly then. Then there was the time it seized during the national at Firebird, but I caught the clutch in time, broke the seizure lose, and continued to a fourth-place finish. My TZ was always clean and competitive; I was lucky and blessed to have Biganski in my corner. He is now working at Moto Classic Garage in Inglewood, California.

In 1996, Steve rebuilt the engine in my TZ750 streetbike, and that was about the last big project bike Steve was involved in until Thad Wiley called him about this Honda CR500 supermoto bike. Steve’s skills have turned to building two- and four-stroke motocross engines, but he referred to the TZ750 project when discussing this CR500.

“You know how these project start, right?” Steve asked me. “Somebody gets a hairbrained idea to put lights and a license plate on a TZ750, for instance! I still remember the disappointment in your voice when you pulled that TZ750 out of the crate…it was the biggest piece of crap we had ever seen. Chris Geiter did the chassis, I did the engine, and, next thing you know, King Kenny Roberts is doing 80-mph wheelies all around Hickman.

Steve Biganski and Chris Geiter
Steve Biganski completely reworked this TZ750 engine while Chris Geiter did the rest. It is still going strong 21 years later. | Photo: Nick IenatschNick Ienatsch

“This CR Supermoto was the same thing. Thad called me with the idea and I was all gung-ho and excited, then it shows up and needs to come all the way down to the frame. Both bikes, a TZ750 and a CR500, will hurt you if they’re not right, so a supposedly simple project becomes eight months of work.”

Fortunately it’s work that Steve loves, and he is very good at it. “I shortened the shock and fork slightly but wanted to keep the swingarm angle close to stock, and grafted on a CRF450 front brake. Swingarm and steering stem bearings were all jacked up, the shock spacers were missing. Supposedly the engine had been redone but when I poured oil in, I discovered there was no clutch-cover gasket! Who does that kind of thing? After seeing that, I yanked the pipe and pressure-tested the engine, finding air leaks at the reed cage and base gasket. That scared me even more, so I pulled the engine all the way down.”

added 10mm to the stock pipe’s header length
Biganski added 10mm to the stock pipe’s header length to improve low-end. “Bud Aksland told me that the beautiful thing about two-stroke tuning is that it yields immediate results, and [FMF’s Donny] Emler’s smaller core really made this CR rideable. Oh, and it’s geared to run 122 mph on top.”Thad Wiley

Now Thad Wiley has his first hot rod and it’s a good one.