1978 Honda CBX1000
Building a road-going tribute to any World Championship-winning race bike is difficult enough. Using an engine four times as big makes it nigh on impossible. Luckily no-one told Queenslander Tom Dermody and his good mates Nic Comolly and John Boyd.
Tom is no stranger to interesting machines, having accumulated over the past 40 years an enviable quiver of road and racing bikes, including a Yamaha YZR500 and TZ250, a Vincent-powered Norton, Suzuki RGB500 and GS1200 and no fewer than four highly collectable Hondas; an RC 30, RC 45, SP1 superbike and a replica of the RS1000 endurance racer.
“About eight years ago, a friend of mine, Nic Comolly from Nicom Engineering, modified a GS1000 Suzuki and did a beautiful job,” Tom says. “One day, Nic, John Boyd and I were chatting and decided a CBX1000 made to look like a Honda RC 166 race bike for the road would be cool. So John, being a hoarder of all things motorcycle, had a frame and an engine and delivered it to Nic’s workshop to start the modifications and rebuild the engine.” Seven years later their improbable dream was done.
The RC 166 was Honda’s response to losing their 250 World Championship to Yamaha’s Phil Read in 1964 and 1965, as two-strokes came to dominate the smaller GP classes. Honda had won its first World Championships in 1961, a double with Mike Hailwood winning the 250s on a four-stroke four and Aussie Tom Phillis the 125s on a four-stroke twin. Hailwood then bailed for MV Agusta, where he won four 500 Championships on the trot. He was replaced at Honda by Rhodesian Jim Redman, who promptly won the next two 250 titles and no fewer than four consecutive 350 crowns.
Honda was determined to win back the 250 class in 1966, pulling out all stops by rehiring Hailwood after having developed a new DOHC 24-valve 249cc inline six, the RC 166, which made more than 60hp at a screaming 18,000rpm. Mike the Bike duly took out the 250/350 double that year — the latter on a bored and stroked 297cc version — and the following one too, before Honda withdrew from GP racing in 1968 to focus development on what would become the game-changing CB750 street bike.
Honda would have to wait for Fast Freddie Spencer to come along before it won another GP Championship, in the 500s in 1983 and the 500/250 double in 1985, albeit on two strokes. Honda did however revisit the four-stroke inline six with the CBX1000 roadster in 1978, which is where our story gets even more interesting. The tiny RC 166 was designed by Honda staff engineer Shoichiro Irimajiri, who not much more than a decade later would be leading the team designing the CBX1000. “The CBX six is a direct descendent of those (sixcylinder Grand Prix) race engines (from the 1960s),” Irimajiri told Cycle magazine at its launch. “That's one reason it only took a year and a half (to develop the CBX) — we had the engine technology from our GP racing experience."
So the idea of building an RC 166 tribute from a CBX1000 road bike has a certain symmetry to it, and Tom Dermody certainly had the right team on board to pull it off. All fabrication, assembly and engine building was by Nic Comolly at Nicom Engineering, while John Boyd was the “artistic boss”, Tom says. “John called the shots on what it should look like and what goes where, and also gathered up all the parts required.” Gun painter Mark Harwood, whose Bumblebee Yamaha R1-Z custom and Widow Maker Kawasaki H2 restoration were featured in Retrobike #37, laid on the jam and decals.
The 1978 engine’s internals were kept stock, with the exterior beautifully presented and dressed with anodised rocker and crankcase covers. A Dyna 2000 ignition provides the sparks. Carbs were swapped for a rack of Keihin CR flat-slides and the six-into-six exhausts were custom-made by Tranzac Motorcycle Exhausts in Brisbane. “They exactly replicate the RC 166 race pipes,” Tom says. “Tranzac did a brilliant job.”
Nic braced the chassis for strength, tidied up the seat loop and modified the frame to accept a Ducati 900 Super Sport twin-shock swingarm and Bimota triple trees clamping beefy 43mm Bimota conventional forks in place of the spindly 35mm originals; 17-inch alloy rims (3in front, 5in rear) are laced to 900SS hubs, and front brakes upgraded to four-spot Brembos on 300mm rotors.
The fuel tank was also hand-crafted by Nicom, as was the rear mudguard and solo seat unit upholstered by Lee Brothers & Co in Albion. A 900SS replica fairing looks the part and houses a Speedhut tacho/speedo and an SS headlight. Clip-ons are from Bimota carrying custom switchgear and levers by Nicom, who also turned up the footpegs and controls.
“The bike was put together under the watchful eye of John Boyd and delivered to my workshop fully assembled and unpainted,” Tom says. “I then dismantled the bike back to its bare frame and Mark Haywood took it away and did the most outstanding paint job to everything on the bike, including the engine. It came back to my workshop with all parts painted and was assembled by myself.
“I then took it to Graham Eyre, a retired electrical engineer, and he did the most beautiful wiring job and installed the ignition on the bike.
“After that I took it back to my workshop and put oil in the engine and fuel in the tank. I fi red it up for the first time and took it for a ride up the street and back. What a sound! Now I just want to register and ride it.”
While the build took some time, it came together without any problems, which Tom puts down to having a clear plan and the right engineers and people involved.
“I’m very happy with it,” he says. “It was well worth the effort. I wanted to have the sound and look of a Honda RC 166 race bike for the road. I love the idea of having a bike that you cannot buy in a shop.”
ENGINE Air-cooled four-stroke inline six; chain-driven DOHC, four valves per cylinder; 64.5 x 53.4mm for 1047cc: 9.3:1 comp; wet sump; 6 x Keihin CR flat-slides; Dyna 2000 ignition; custom Tranzac exhausts; multi-row chain primary to wet clutch and five-speed gearbox; chain final drive; rebuilt by Nicom, tuned by Steph; 105hp at 9000rpm (stock)
CHASSIS Steel tube frame with engine as stressed member, braced and modified by Nicom; 43mm Bimota forks and triple trees, 2 x Brembo 300mm rotors with four-spot calipers on laced 17 x 3in alloy rim; 900SS twin-shock swingarm with small Brembo disc on laced 17 x 5in alloy rim; Pirelli tyres
BODYWORK Tank, seat and mudguard by Nicom; 900SS fairing and headlight; paint and graphics by Mark Haywood; Speedhut tacho/speedo