Each week our team of experienced senior road testers pick out a new model from the world of innovative, premium and performance badges, and put it through its paces.
The Z900RS is all about heritage – and what heritage it is. Kawasaki’s defining two-wheeled creation is the Z1 of 1973. The mighty, DOHC 903cc four was the world’s fastest and most glamorous superbike until 1976 when it was updated to create the original Z900. Those Seventies “Zeds”, as stylish and robustly engineered as they were potent, established Kawasaki as a motorcycling force and now change hands for five-figure sums.
The Z900RS comes from a more recent family of Kawasaki fours. The Z750 of 2004 was only moderately powerful but its looks and competitive price helped make it popular. The Z800 that followed in 2013 was also successful and led to last year’s Z900, which combined similarly edgy, modern styling with a traditional tubular steel frame. The Z900RS, its initials standing for Retro Sport, adds nostalgia to the format. There’s also a café racer derivative, the Z900RS Café, featuring a bikini fairing plus paintwork in Kawasaki lime green and white.
Essentially the RS is a modern Z900 with the look of a classic Z1, notably from its tear-drop petrol tank, well-padded dual-seat and distinctive, duck-tail rear end. The one-piece handlebar is higher and further back than the Z900’s, giving a more laid-back riding position in combination with footrests that are lower and further forward. A modified frame gives more relaxed steering geometry; new thin-spoked alloy wheels resemble wire-spoked Seventies originals.
The 948cc, liquid-cooled 16-valve engine is detuned with softer cams, reduced compression and a heavier crankshaft. This boosts midrange torque while cutting maximum output by 14bhp to 109bhp – still 27bhp up its famously powerful Z1 inspiration. Kawasaki resisted the temptation to use an old-style chassis layout, instead giving the RS upside-down front forks and a rear monoshock, plus a front brake upgrade that adds monobloc calipers to the Z900’s twin discs.
Peak power might be slightly down on the Z900’s but the RS generates plenty of straight-line thrills, plus useful extra flexibility. There’s more torque below 7,000rpm, giving the Kawa a pleasant, old-school urgency from low revs, and an shoulder-loosening surge of midrange acceleration as it heads for a top speed of about 140mph. Less welcome is a slightly abrupt throttle response that is sometimes noticeable when exiting slow turns.
Chassis performance is excellent, whether the RS is being ridden gently or hustled down a twisty back road. It remains stable at speed yet steers with a light feel, helped by the leverage available from its wide bars. The suspension is sufficiently refined to give taut handling as well as very respectable ride quality. A new traction control system and the powerful, ABS-equipped front brake add a level of safety that riders of the original Z1 could not have imagined.