It’s interesting to contemplate how BSA A10s, or any other old British twin, would’ve turned out if they'd been produced on modern, high quality machinery and assembled with precision and skill. For sure, most modern A10s have been re-engineered and rebuilt to a standard that the factory couldn't have hoped to match. But that still doesn’t match the quality of engineering the Japanese had somehow achieved in the seventies, and even the sixties.
Enter Kawasaki's big twin, a replica of the old A10 that was only put out of its misery when they mastered the art of four cylinder engine production in 1973. Few were exported to Europe or the States, but enough survive in the latter for them to have obtained minor cult status. On one of my trips to the land of the insane, I came across a '73 model, owned by one Dave Wilson, who was ignorant enough of the ways of the UMG to let me have a spin. It's amazing how trusting the Yanks become when approached with a British accent.
The bike had only done 14000 miles, was in stock trim and with a bit of tidying up around the edges could have passed for new. Amazingly, where you'd expect to find the magneto on an A10, there was an electric start, which may or may not have been standard fare. No-one seemed to know. It clattered away for a good two minutes before finally catching. The throaty roar of the exhaust could easily have passed for a BSA.
Missing from the Kawasaki was that immediate feel of being at home with the controls. The bars were too high, and the seat left me feeling perched atop the machine; the petrol tank too poorly shaped to caress my knees. The engine, despite sporting twin carbs and over 50 horses, was smoother than the A10, though not without some tingling reaching the bars and pegs at low revs. The drive chain didn't settle down until there were at least 2500 revs on the tacho, neither did the motor have any discernible torque below those revs. Wafting along in fourth on a whiff of throttle was out.
The engine became a different beast between 3000 and 5000 revs. Smoothed out, grunted out some torque and power, shifted niftily even in top gear. From 5000 revs onwards the power really zapped in. If the bike hadn't weighed a faintly ridiculous 475lbs, it would've been harder charging than a good Bonnie; as it was they were about equally matched. A big Commando would stomp on it, mind.
The engine was quite willing to rev to eight grand without going into the usual frenzy of self-destructive vibration so beloved of the BSA, which at such revs would explode its crankshaft. The RS thrummed its pegs, bars and tank but I could live with it for short bursts. A 90mph cruising speed was quite possible, as between 75 and 90mph the engine found its sweet spot. Smoothed out to an acceptable degree.
No doubt, the excessive mass it was carrying helped it to absorb the vibes. It was a trick the Japs used time and time again on their big twins - XS650, Z750 and even the TDM850. The British factories preferred a sporting edge, hoped the riders would just grin and bear the vibration in exchange for the thrills of the acceleration. '
The A10 was a solid enough handler in later guises. Not up to Featherbed standards but never coming close to the ball shrinking dangers of a Speed Twin. The frame on the RS looks a dead ringer for the A10s, as well. The same kind of duplex affair with skimpy swinging arm, bits of it looking like they were inspired by some old pushbike.
But with its extra mass, the Kawasaki was far from as assured as the old Brits. A lot of this was down to that old bugbear, suspension with minimal damping. On the Yank roads I rode out of New Orleans there wasn’t much swervery but the fast curves I came across were bad enough.
I'd regularly howled down them at 120mph on a V-Max with barely a tremble from the chassis. On the poor old Kawasaki, 80mph had it setting up a gentle oscillation, an almost classic hinged in the middle feel. In a moment of madness, I thought I'd open her up and see what happens. These days it's very easy to forget how bad handling the old Japs were - a layer of nostalgia and outright lies obscure the truth; magazines churning out what the readers want to read rather than the reality.
The reality of accelerating quite hard when leant over with the chassis already loose was one hell of a lot of tail wagging. I almost lost it all, thought the bloody thing was going to turn right round. I didn’t want to slam the throttle shut because old Kawasakis (who mentioned the H1 or Z1?) tend to fall in half when you do that.
Fuck it! The road was wide and there was sod all else coming the other way. Heaved the brute up to the vertical and slammed the throttle to the stop. By the time we'd hit 110mph it’d pulled out of the wobble and was merely weaving - or that might just have been my shaking hands.
A pair of Girling shocks would probably clear up most of the handling mess, though I’m not one to trust the steering geometry of this era of Kawasakis. The front end was quite harshly sprung, the deficiency in damping less noticeable.
Considering that Kawasaki equipped their 82hp, 510lb Z1 with a single disc, the presence of a pair of discs on the classically shaped RS was curious, to say the least, but explained the stiffness of the forks.
These were early seventies’ discs. Little by way of feel or feedback and with a death-wish in the wet (according to the owner). They worked quite effectively the few times I had to deal with dozy drivers, both blind and deaf. If you ever go to the States and end up giving a cage a good kicking when it gets in the way, don't stay around to argue the toss - most of the drivers are armed!
Overall, I'd much prefer my re-engineered A10 to the RS - that’s after an afternoon sunny’s ride, so not a definitive resolution. At least as it stands. The bike’s just too clunky and remote, if not dangerous, to ride at a reasonable pace. Shedding mass, upgrading the suspension and doing something about the saddle would all help.
But these Kawasaki 650’s aren't bargain priced, $2000 to $4000 depending on condition, which makes a UK based A10 a much better proposition - you can pick up a nicely modded one for around £2500, though it would get laughed at in a concours competition. One, thing, though, the RS didn't besmirch its image by as much as one drop of oil - quality engineering, see! I wonder, would the excellent engine slot straight into my A10's frame?
Johnny Malone