Motorcycle Sketchpad: Commentary
Forty-five years ago, in March of 1972, I was a 16 year-old junior at Hurley, Wisconsin’s J. E. Murphy High School.
I don’t recall what classes I had each semester that year; I imagine they included the obligatory English composition, biology, some sort of science—chemistry, maybe, algebra and my personal favorites, gym and study hall.
There were times the lecture in those classes was so confusing, I thought they were being taught in a foreign language—Greek, maybe, in algebra—just to frustrate me and keep me from achieving the dizzying heights of a 2.5 GPA.
Language comprehension problems aside, I had other things on my mind—I know what you’re thinking—no, not that, at least not during school hours.
I was making plans and putting them down on paper for later use. My company, S. S. (Super Sport) Engineering would build custom racing motorcycles and snowmobiles for the world’s elite competitors.
To fill those otherwise vacant hours spent in class fighting off sleep, I was dreaming up motorcycles. At the time, I saw no practical application for trigonometry, algebra and chemistry to the art of motorcycle design. If you read enough motorcycle magazines, you could get all you really needed to know. I have since revised my stance on that, though you can still learn a lot from motorcycle magazines.
I think the teachers were impressed that I hauled a quadrille-paper notebook around as a motorcycle sketchpad. When they saw me hunched over it during class, pencil flying, I think they really thought I was taking class-related notes!
I am reminded of that notebook by the discovery of one of my vintage sketches dated March 20, 1972 in my old textbook on Technical Illustration. Yep—I’m one of those cranks who can’t throw anything away. The sketch is of what I was sure would be a world-beating road racer, sans fairing, and I had even included some of the key technical specifications. Looking back on it, I may have been a bit off on some things.
It would be powered by an air-cooled two stroke triple a-la Kawasaki H2R of that day—but it would have been an engine of my own design, of course. Mine would have been one up on Kawasaki’s Green Screamers because mine would have had 31mm Ord throttle body fuel injectors instead of those finicky carburetors. I didn’t know squat about fuel injection, but it sounded cool and I had seen articles about it in some magazines.
With a 12.5:1 compression ratio, my triple would have boasted 99.3 hp at a leisurely 12,500 RPM. Pretty tame by today’s standards, but in 1972, those would have been imposing stats. Oh, sure, I could have fantasized about 150 hp at 17,000 RPM, but I wanted my engine to last! It was equipped with three completely unrestricted expansion chambers. I had first heard the howl of such pipes on professional snowmobile racer’s machines at the Ironwood (MI) Snowmobile Olympus. If the bike never won a race, I knew one thing: it would have a sound that could melt your fillings.
Looking at the sketch now, I see some potential design flaws. The fuel tank looks like it could hold about 15 gallons. Apparently the concept of refueling during a race was not part of any racing strategy I could envision. The rear shocks look like the jam pots off a 1955 Matchless with about an inch of travel; no matter, paved tracks should be smooth. It had a nice seat that extended up over the aft end of the tank, though.
It was state-of-the-art with CD ignition in the specs, but I might have gone a bit overboard with a 14 plate dry clutch that would probably require the rider to have forearms like Popeye. I also specified quadruple row primary drive chain and an eight speed gearbox that would have required the rider to practically pedal the thing with the gear change lever around any road course. Well, those peaky two-strokes were tough to keep in their narrow power band! Apparently, all that hardware explains the enormous cases below the engine.
Hydraulic disc brakes, which were still pretty novel on street bikes in ‘72 were provided front and rear, though by the looks of the calipers, they’d have been single piston jobs. Still, that would have been pretty high tech for the day and better than most drum brakes—except for maybe those gigantic four leading shoe Fontanas they used to make for up front before disc brakes took over.
The rims and tires, well, those are anybody’s guess. Spoked wheels—let’s say they were Borrani, tires were the latest exotic sticky compound Dunlops and the forks were Ceriani, ok? Nothing but the best.
The chassis, well, I’m not quite sure what I had in mind there. It looks like some sort of tubular—let’s say chrome moly—material that would be sort of a triangulated, gusseted and bolted cradle style. Massive and heavy-looking, I guess I was determined to prevent the frame flex problems that gave the Kawasaki triples of the day such a bad handling rep and earned them the nickname, “Widowmaker.” I probably should have spent some time studying articles in the motorcycle magazines about the Rickman frames.
As it turned out, I never did build my S. S. Engineering Special, nor anything remotely like it. My interest in racing bikes has never waned, though. My doodling in high school grew into an interest in mechanical design and drafting and I went on to get a degree in it from Gogebic Community College in Ironwood. At least in those classes, doodling designs of machines was part of the curriculum.