RZs rule
With the benefit of hindsight it seems obvious that the post-war British motorcycle industry lived on its past glories for too long. While Norton, Triumph and BSA soldiered on producing singles and twins, their Japanese counterparts forged ahead producing reliable, affordable smallcapacity bikes with increasingly sophisticated engines. Without doubt the CB750 released in 1969 was a landmark machine that paved the way for the incredible performance capabilities of modern 1000cc sports bikes. Mr Moor (‘John Bull rules’ OBA 41) should set aside his rose-coloured glasses for a moment when waxing lyrically about his old BSA and other Brit bikes of the 1960s while pouring scorn on Japanese machines. Perhaps he has forgotten the oil leaks, dodgy electrics, sundry parts that were prone to go missing in action, and numbing vibrations associated with “British bulldogs” of those days? In any case the monstrous allegations he makes against the Yamaha RZ 350 (“these ghastly death engines equipped with Dr Kaaden enhanced lawnmower motors, front ends apparently sprung with bags of marshmallows …”) simply cannot go unchallenged. A direct descendant of the Yamaha TZ 250/350s racing bikes, the water-cooled 2-stroke twin produced 59.1 bhp at 9000 rpm and was a giant killer in its day. The RZ was equipped with an ingenious electronic power valve system (YPVS) that largely overcame the 2-stroke Achilles heel of narrow power bands and smoky exhausts. YPVS made the engine much more tractable for road use while catalytic mufflers helped in reducing exhaust pollution. I own a 1983 model RZ that I used for commuting, touring and some club racing in the 1980s before storing it away while I was overseas. Following a recent restoration it’s back on the road and I can vouch for the fact that it’s still a brilliant little bike. Admittedly fuel economy is not a strong point, especially if ridden with some, ahem, exuberance. But rest assured Mr Moor, an RZ can go around a corner in excess of 6,000 rpm without tying itself into knots. Admittedly a sporty lightweight may not suit someone more attuned to the languorous rhythm of many old Brit bikes but in motorcycling, as in other walks of life, the old adage still applies, different strokes for different folks. In the face of tightening emission controls and noise restrictions, 2-strokes have of course largely disappeared. The banshee wail of high revving 2strokes, the soundtrack of motorcycle racing through the 1970s and ‘80s, is a fading memory. Unfortunately modern fuel injection technology and electronic control systems have not been used to develop a new generation of clean burning 2strokes given the well-proven advantages that this engine design offers – an outstanding power-toweight ratio and simplicity. Roger Butterworth Coogee NSW