by Gary Charpentier
For the second and last part of The Superhawk Cafe, we feature a bike which embodies the purest essence of the Cafe Racer ethos. Once again, we turn back the clock to the 1960s, where we find DJ Murfin club racing `round the UK on a hybrid Honda built on a CR 72 chassis, with a CB77-derived engine. Bored out to 350cc and sporting a 5-speed gearbox, this was no standard Superhawk lump. DJ tells me the bike was fast, competitive against the majority of 350s around at the time, and with the fairing in place many of his competitors thought they had been beaten by a CR72. Life was good until the 2-strokes started to appear on the grids. When the TD2 Yamahas began showing up at the club level, DJ decided to retire his Super-Superhawk to a relatively quiet life on the streets.
The plan was to keep it looking as much like a race bike as possible, only substituting CB77 road gear where necessary to keep it streetable and road-legal. By a happy coincidence, the CR72 race kit 4LS front brake became available during the conversion, and it bolted right up. The decision was made to use a modified CB160 front fender, with its straight stays it looked much closer to the genuine race part than the SuperHawk item. Racing clip on handlebars were retained together with a pair of custom-made headlamp brackets to carry that classy Superhawk headlamp and speedo assembly. This completed the front of the bike.
Modifying the Superhawk rear fender was the next stage. This just required a bit of re-shaping to clear extra cross tubes in the CR frame. Drilling and tapping the fender fixing holes in the (plain) mounting bosses caused a bit of head scratching, but again the end result was worth the effort. Similarly a standard Hawk chain guard was re-worked and mounting brackets made up with good results.
Surprisingly the exotic works race frame carried a pair of mounting holes just right for a CB77 center stand (No side stand was ever fitted on this model) but no anchor bracket for the return spring, a suitable item being copied from the hawk frame and bronze welded into place. The only mod required here was to lengthen the stand by 1″ to lift the bike clear of the ground. A few more brackets were needed for things like ignition switch, horn, rectifier etc., all these were cannibalized from a damaged standard frame to keep the authentic Honda appearance. Battery was mounted crossways in a custom carrier underneath the carburetors, and filled the empty space neatly.
A C72 side cover was substituted for the CB item to allow a rear-acting kick-start. A forward facing one would have been impossible to use with the long race tank and resulting seating position, again off the shelf Honda items were used for the change. No electric start was fitted.
This was really the extent of the work needed for the conversion but at this stage a lot of time was spent making sure everything fitted together “just so” and that any fabricated parts looked factory made and not home made. Some fresh paint, in factory race colors obviously, and the “new ” bike looked like something that could have come straight from Honda’s production line. A short technical inspection and by the local Licensing Authority followed, a license number was allocated and they were ready for the road.
How did it go? Well at least as good as it looked, rather too well in fact. The initial engine build, to full racing spec with race camshaft and raised first gear ratio proved just too uncomfortable for regular street use. Installing the standard Honda camshaft, and re-installing the ignition advance retard gave a much better result, the engine was smooth and drivable with plenty of power from its 347ccs, the five speed gears meant that the engine was always inside its wide power band and acceleration was impressive from any speed. The ride was firm to say the least but handling from the race-designed chassis was razor sharp, ground clearance from a bike less than 18″ wide across the pegs was never an issue.
Race bred brakes meant that two fingers on the lever could produce a tire-squealing stop if required, but smooth powerful braking was also there with a little practice. Top speed was well into three figures; the works front hub did not feature a speedometer drive so actual top speed remains a guess.
Was it worth the effort? Very much so, the result was a unique but very useable special, which attracted attention wherever it went. On the road it could hold its own with the bigger and newer bikes of the late `70s, and by then it was almost twenty years old! The very essence of a proper cafe racer, but its days on the street were numbered.
Why? Because in 1980 the Classic Racing Motorcycle Club was formed, and the opportunity arose to once again compete against equivalent machinery on tracks like Snetterton and Donnington Park. This Super-Superhawk enjoyed another competitive racing career with CRMC throughout the `80s, culminating in a run at the Classic Manx Gran Prix in the early `90s in which it finished mid-pack. How is that for pedigree?
These days the bike remains in full-race trim, constantly evolving as better parts become available. Some upgrades include a Nova 5-speed racing gearbox to replace the aging and tired original Honda item. The Amal Mk 1 carbs have been replaced by a pair of Keihin CRs. Asso racing pistons have replaced the British Hepolites, and a Motoplat electronic ignition has been installed. The bike is used occasionally for parade laps and is always ready for the next opportunity to be used in anger. Racing is in the blood, they say, and I would add that it must reside in the crankcase as well.