The rise and fall of the 'Sports 600'

For 30 years one class of bike dominated UK sales charts, selling in the tens of thousands, becoming a vital stepping-stone in almost every biking career. It was a default rite of passage; the backbone of British motorcycling. This is the story of the rise, and fall, of the sports 600.

Pre-history

Once upon a time there was no such thing as a sports 600. Back in black and white, pre-1985 days, air was used to cool engines, the number of valves in an inline four cylinder head could be counted on the fingers of two hands (or just the one, if you came from the Fens) and a short stroke was an adolescent nocturnal proclivity rather than something to do with engine architecture. In the early ’80s, the world of the sports middleweight was a random mash-up of straight fours, V-twins, V4s and parallel twin and single cylinder four-strokes, with a splattering of hair-brained two-strokes. Capacities ranged from 350 to 650cc, and the bikes mostly made around 50bhp, did just over the ton, and were predominantly naked roadsters; a few had a bikini fairing, or a half-fairing at best.

So the only thing you could say for sure when you graduated from your 125cc learner bike was that there was a lot of choice. Yamaha RD350LC or Honda VF500? Kawasaki Z650 or Suzuki GS650G Katana? You could even have a Honda CX650 Turbo...

The first sports 600 - 1984 Yamaha XJ600

But by the mid-80s, the Japanese factories’ development efforts had begun to converge on one specific engine type and capacity, as each attempted to out-manoeuvre the others. Honda’s CBX550 F2, Kawasaki’s GPz550 and Suzuki’s GSX550ES were 550cc air-cooled inline fours, with luxuries such as adjustable monoshock rear suspension, adjustable forks, disc brakes and half fairings.

Only Yamaha lagged behind, with an aging XJ550 whose twin shocks, basic forks, absent bodywork and drum rear brake suddenly looked a generation out of date. But when, in 1984, an updated XJ was introduced, complete with monoshock suspension, a half fairing and disc brakes all round, it also included a bored and stroked-out motor that increased capacity to 598cc for good measure. Yamaha called it the XJ600.

Increasing capacity is the easiest and cheapest way to make more power than rival engines – Honda’s CBX550 and Suzuki’s GSX550 were actually 572cc motors – and it wasn’t the first and wouldn’t be the last time a manufacturer deviated from the norm to get a spec sheet and showroom advantage. But taking the motor any bigger than 600cc was pointless because Yamaha knew their revolutionary FZ750 was only a year away from release; a 650 would be too close.

And then there was the fact that in many markets, 600cc was an upper limit cut-off point for cheaper insurance. So, 600cc it was.

The first race replica 600 - 1985 Kawasaki GPZ600R

The bow wave of development in the wake of Kawasaki’s water-cooled, 16-valve inline four GPz900R in 1984 changed the shape of motorcycling in Europe – and especially in the sportsbike-mad UK. The following year, in 1985, the giant-slaying Kawasaki GPz600R made every mid-sized four-stroke suddenly look genteel and hum-drum. Here was a 600cc machine that took the latest bike technology and focussed it into a tiny, compressed ball of fury that competed, and beat, any of the previous generation of superbikes. If you had a GPz1100, or a GSX1100, or a CB900 in 1985 and you came up against a handy 600R, you were toast.

That technology was largely inherited from the GPz900R, with a bit of GPz550 – the 592cc motor’s bottom end was based on the GPz550’s, keeping the same 52.4mm stroke. But bores opened out 2mm to 60mm and, with a four-valve head design, meant more valve area flowing more air and making more torque. Which, with more revs, means more power.

Kawasaki claimed 75bhp at 11,000rpm and 45 lb.ft at 8000rpm – enough for 135mph; 15mph more than the GPz550. More engine performance meant more heat, so –  like the GPz900R – the 600R had a fan-assisted water-cooling jacket. It didn’t matter what the motor looked like because the engine was now hidden behind a full fairing.

The 600R’s chassis used a steel perimeter frame around the motor, instead of a spine frame over the top, with an aluminium swingarm, adjustable Uni-Trak rear suspension and adjustable anti-dive forks combined with large (for the time), twin 270mm discs and fat single piston calipers. Cool stuff. Radial Dunlops – not crossply rubbish – on 16in wheels topped the chassis spec off, and enabled the GPZ to run radical steering geometry. It was the first four-stroke road bike that went, stopped and handled like a race-bike. It was a race replica.

The aerodynamic 600 - 1987 Honda CBR600F

In the mid-80s Honda had a several middleweight machines that could conceivably be called sportsbikes – the CBX550 inline four, the VF500 V4, the two-stroke NS400R and the single cylinder XBR500. By 1987 – at least in Europe – there was only one: the CBR600F-H.

CBR stands for City Bike Racing, which makes the intention of the 600F plain enough. Launched at Honda’s legendary Suzuka circuit in Japan, the CBR was the polar opposite of the beloved VF500 it rendered obsolete. The VF’s V4 motor was highly complex and demanding to produce, but was underpowered. The CBR’s watercooled, 16v, inline four was mechanically straightforward, but built to rev with an extreme bore/stroke ratio, and also built to last. A 12,000rpm redline gave a class-leading 80bhp and over 140mph, but the engine was also capable of running up to 80,000 miles without so much as an oil change. The chassis was unremarkable too – no aluminium here; but the steel tube twin spar and steel swingarm were obscured by completely enveloping bodywork, lending the CBR600F-H its ‘jellymould’ nickname. Honda claimed it was the most aerodynamic motorcycle in the world. It was also lighter than GPZ600R, and had better handling (17in wheels front and rear), better brakes and better suspension.

But, best of all, the CBR600F-H was an almost perfectly balanced bike – a seemingly alchemic conflation of engine, chassis and riding dynamic that produces a bike that suits most of the people, most of the time and goes on to ubiquity – almost all of us have either ridden, owned, or know someone who’s owned a CBR600 at some point. The VF500 was in production for two years. The CBR600F ran almost unchanged for 12 years – and the engine isn’t so far removed from the unit currently powering the Moto2 grid. That’s a hell of a legacy.

The two-stroke four-stroke 600 - 1989 Yamaha FZR600

And where, in all this 600cc development, were the guys who started it all? Yamaha bodged along for a few years between 1986 and 1989; after the XJ600 came the FZ600 – it used the same air-cooled, eight-valve motor as the XJ, giving away 20bhp to its rivals, and wrapped in a steel tube frame painted to look like aluminium, with a sporty full fairing and radical sports riding position. It weighed 15kg less than the GPZ600R and was a good effort at plugging the gap.

But in 1989 Yamaha did that thing they do from time to time, and built something truly insane.

The 1989 FZR600 is often called the two-stroke four-stroke 600, or the LC 600. Unlike the bigger, five-valve FZ750, the FZR600 stayed at a water-cooled four-valves per cylinder – but with a relatively long-stroke design compared to Honda’s CBR600. This gave the engine fantastic low-down punch and a very short, compact power delivery. Combined with a slim, flyweight, sharp steering chassis and fairly crude suspension, it made the FZR600 a lively, ball-busting and incredibly entertaining ride. It was the hooligan of the 600 class; a hilarious, riotous romp from the moment the engine rasped into life right up to the moment the oil light came on. Which it did. A lot.

The 160mph 600 - 1990 Kawasaki ZZ-R600

By the end of the 1980s, a pattern was emerging; 600cc production racing – soon to be called Supersport – was hugely popular across Europe as the new breed of sports 600s proved themselves as capable on track as on the road (or at least the CBR600 and FZR600 did; Suzuki and Kawasaki only found success by cheating more than the others).

But in the showrooms the merits of out-and-out sportiness versus road-biased practicality was still up for grabs. Was Honda’s CBR600F so successful because it was really sporty, or because it was also really practical? Or was it both? Or would a compromise please no-one?

Kawasaki’s answer to the CBR’s domination was to build the ZZ-R600 and launch it in the South of France alongside the ZZ-R1100. Like the bigger bike, the 600 was by now fully wrapped in plastic fairing – but had taken a step away from the pure sports design of the GPZ600R and GPX600R predecessors. Although the ZZ-R motor was based on the GPZ design, the new frame was aluminium (one of Kawasaki’s first) and the ZZ-R’s riding dynamic was much closer to a sports tourer than a race bike – long, low, softly suspended, relatively heavy and with a booming, immensely muscular power delivery that felt just like a smaller version of the 1100.

But not that much smaller: the ZZ-R600 was, in 1994, the first 600 to trip timing lights at over 160mph – helped, in part, by ram-air force-feeding a pressurised airbox. That made it faster than most 750s, and only 10mph or so down on the ZZ-R1100. That fast enough for you?

The 100bhp sports 600 - 1995 Kawasaki ZX-6R

Plainly, the answer was a resounding ‘No!’. In 1995 the ZX-6R ditched the ZZ-R’s sports touring thing and went for sportsbike broke. There wasn’t a lot of ZZ-R left in the 6R; an all-new motor did the shorter-stroke, wider-bores thing, for extracting more bhp from what was – and still is – largely the same mid-40s lb.ft of torque anyone can extract from a conventionally aspirated 600cc inline four (without cheating). But, like the ZZ-R, the ZX-6R squeezed as much gas as it could into the combustion chambers thanks to ram-air – and it was lighter, shorter, snappier and more track-focussed; a return to Ninja values.

And, of course, there was the power. Depending on whose dyno you trusted, the ZX-6R made between 98 and 101bhp – which is good enough to qualify for the title of ‘First 100bhp sports 600’. And it wasn’t just impressive on the rolling road – on a real road, the ZX-6R went even quicker than the ZZ-R600 – over 163mph, and a sub-11s standing quarter mile. Still faster and quicker than every 750.

Suzuki’s first sports 600 - 1997 Suzuki GSX-R600 SRAD

And where have Suzuki been all this time? The GSX600F was introduced in 1988, and initially the motor was an impressive, standard, first-generation GSX-R750 air-oil cooled inline four, with the 750’s bottom end, same block with narrower bores, and the same head and combustion chamber shape with smaller valves, less cam duration (same lift) and smaller carbs. The result was a class-equalling 75bhp or so and mid-130mph top speed. But the GSX was 20kg heavier than the other 600s, and it looked like a teapot and with budget suspension and brakes. It was also the cheapest of the sports 600s and quickly acquired a tag as the budget option compared to the rabid FZ600, racy GPX600R and sublime all-round CBR600F of the day. It was definitely not a GSX-R600.

In 1993 the new Suzuki RF600 switched to a proper bream frame (still steel), adopted distinctive, sharper, slatted styling, and widened the GSX’s bores in search of more top end power. Suzuki found it, with the RF making a claimed 98bhp at 11,500rpm, but they lost a chunk of midrange in the process, leaving the 600 feeling a bit peaky. Which would be okay for an out-and-out sportsbike, but the RF’s riding position was more upright than equivalent CBR600 and FZR600, and wheelbase and weight were closer to the ZZ-R600’s numbers. And 110-mile tank range was terrible. In trying to be a sport-tourer and a sportsbike combined – a bit like a CBR600 – but ended up being neither. And it was still not a GSX-R600. Ahem.

So when Suzuki finally, finally, finally revealed an actual, honest-to-goodness GSX-R600, in 1997, it wasn’t an old-school, oil/air-cooled slabby GSX-R, but a shrink-wrapped water-cooled 750T SRAD. In fact it was mostly a 750. The engine was the same cases – lighter, with smaller pistons, lighter crank, clutch, carbs etc – but still, the same. The aluminium frame, the tank, the intake system, bars, switchgear, lights, battery... all 750 stuff. Swingarm was shorter and unbraced, calipers were 4-pot not 6-pot (good!) and forks were rwu to the 750s usd items.

Sounds like the 750 was the better bike – and yet the 600 Suzuki was a cracker. It was an unashamed race replica, uncompromised by pandering to sports tourism. It was built to be a rocket on the road, and that’s exactly what it was. Fast, agile and fun, it put Suzuki back on the 600 sportsbike map.

The first 200bhp-per-litre sports 600 - 1999 Yamaha YZF-R6

If the history of the sports 600 has shown us anything thus far, it’s that the 600s tend to follow in the footsteps of their larger siblings. The GPz900R begat the GPZ600R, the CBR1000F begat the CBR600F, the ZZ-R1100 begat the ZZ-R600 and the GSX-R750 begat the GSX-R600 (scholars of history can pause here and consider the trick Honda missed by not building a scaled-down CBR900RR FireBlade 600 in 1993...).

And so, it was with no great sense of surprise when Yamaha revealed the YZF-R6 in 1999, the year after the launch of the rather tasty YZF-R1. Unlike, say, Suzuki’s GSX-R600 and 750, the R6 shared no components with the R1, and precious few with the previous Yamaha 600, the sports-tourer Thundercat.

But, like the R1, the R6 was a bit special. For a start, Yamaha claimed it was the first bike to produce 200bhp per litre, claiming 120bhp at 13,000rpm. That was a crank figure; they got the revs right but at the wheel the motor made closer to 100bhp at 12,750rpm. But the R6’s ally frame and swingarm were pure art, and the Yam was shortest and lightest sports 600 yet. It contained much current sports thinking – the motor was canted forward, allowing the airbox to migrate to the top of the chassis just behind the headstock – the best place to get a charge of cold air and to then feed it directly into a downdraught bank of carbs. The fuel tank moved backwards (and shrank!) to make space, centralising mass and lowering the centre of gravity. Meanwhile the transmission moved behind the R6’s block, shortening engine length and allowing better weight distribution and optimum wheelbase (at 1380mm, it was shorter than an FZR400RR).

The R6 was the sportiest 600 yet – and, with a 165mph top speed, it was also the fastest. 200bhp per litre or not.

The British sports 600 - 2000 Triumph TT600

By the turn of the millennium, sports 600s were selling better than ever. A generation of riders, male and female alike, young and old, novice and expert, made the most of the sheer, sexy sportiness of it all.

In 2000, Triumph jumped on the bandwagon with the TT600. It was a brave move; to compete head-to-head with 15 years of Japanese development from a standing start. The TT was a 100bhp 16v inline four, developed from the ground up, running cutting-edge technology such as fuel injection, forged pistons, coated bores and a crazily short stroke, alongside a top line chassis of twin-spar ally frame, fully adjustable Kayaba suspension and Nissin brakes. Styling was a bit chubby, but the TT’s weight was comparable to other sports 600s. It should’ve been a huge hit.

But the fuel injection was a step too far – literally; the Sagem system was flawed, with flat spots and hesitant fuelling that, despite frequent factory updates, condemned the bike. Nice try Triumph. Maybe they’ll have another go...

The cheating sports 600 - 2003 Kawasaki ZX-6R B1

As the 2000s moved on, the Japanese manufacturers pursued the race replica 600 philosophy with renewed intensity. The GSX-R600 transitioned into the K series, the R6 evolved with more power and higher revs, and even the old, faithful, road-friendly CBR600F mutated into the MotoGP-styled RR model with a seriously radical riding position (although Honda sensibly kept the F model alive alongside it).

But it was Kawasaki who really went for it in 2003. The ZX-6R B1 was notable for a couple of speccy reasons: it was the first 600 with usd forks and the first with radial calipers. The motor was, like the last year of the previous model, overbored to a cheaty 636cc – a 600cc version for racing was also available – and this gave it a critical edge in performance over its rivals. But, chiefly, the 2003 ZX-6R B1 will be remembered because all the stuff around the motor looked stunning – a minimal, skeletal design that looked more aggressive than a Great White rolling over and about to bite – and it went like a lunatic. Hard, fast, compact, sharp-steering and explosively powerful, the B1 was a crackers-arsed nut-job of a 600 with big attitude. Not so much a flying K as a flying F. It brought reckless abandon back to the class – possibly for the last time – and, as a chaotic, proud standard-bearer for sportsbiking at its most basic, there was no finer machine.

The best ever-sports 600 - 2005 Triumph Daytona 675

Well, not until Triumph built the 675 Daytona. When the wraps were lifted off the Daytona, everyone gasped – okay, at 675cc it was arguably no more a sports 600 than, say, Ducati’s 748 and 749 (which although quality for race alongside inline four 600s, are, for the purposes of this story, 750s, not 600s). But anyway – just look at it! As a near-perfect example of styling and engineering perfection, the first 675 is up there with the RC30s, 916s and MV Agusta F4 750s of the world and a nailed-on future classic. Sharp nose, aggressive lights, slim profile, sleek tail unit and a tall, spacy riding position with quality suspension and brakes – and that fabulous inline triple motor, churning away producing the best of both worlds – more torque than a 600cc inline four and at least as much power.

The decision to drop the previous Daytona 650’s inline four was made even before the 650 was released – 675 development began almost as soon as the TT600 was launched, in 2000. It was a crucial, but obvious, marketing and engineering move – triples are what modern Triumphs are (apart from heritage twins), and the layout has so many advantages; at the time it was unused by anyone else, it combined perfect primary and secondary mechanical balance, and had unique power delivery characteristics.

The Daytona 675 wasn’t just the last great sports 600. It was also the best. Until now...?

And then, it was over...

As the 2000s rolled over and capitulated into the current decade, the world changed. The credit crunch in 2008 sent prices of Japanese bikes through the roof, and a Japanese sports 600 cost more than a litre sportsbike of only a year previously. But sales of the 600s were already waning, as older European riders – and, especially the once sportsbike-mad Brits – turned away from increasingly cramped and hardcore sports 600s and moved instead to naked bikes and adventure bikes; machines better suited to a modern riding environment and lifestyle.

The sports 600 was suddenly caught, high and dry, stranded and delivering the sensations and thrills no-one wanted, at a price no-one could afford. Development slowed – from the mid 2000s, Suzuki barely lifted a finger to move the GSX-R600 on, Honda changed CBR paint schemes but little else, Kawasaki introduced traction control and continued to restyle the ZX-6R, and Yamaha persisted with the same R6 they’d been building for years. Triumph updated the Daytona with a new engine and chassis in 2013, but from 2016 onwards there’s little appetite for a new pure sports 600. There are no more CBR600RRs, no more Daytona 675s, no more ZX-6Rs and no more GSX-R600s. Only the R6 remains under a new Euro 4 compliant, 2017-guise.

And if that sounds like a downbeat ending to a glorious career, it shouldn’t. All things have a natural span; no-one makes precious, dazzling little 400cc sportsbikes these days either. The world has moved on and if sports 600s were what we all wanted, the factories would still make them.

And, in a way, they still do – the current crop of A2-licence friendly middleweights – bikes like Yamaha’s MT-07, Honda’s CBR650F and Kawasaki’s Ninja 650 – may be a million miles away, in terms of spec, performance and – let’s face it – build quality, from the sports 600s of the 1990s. But they supply just as much fun, and are just as valuable in providing a steppingstone into other areas of biking for thousands of riders.

The age of the supersport 600 might be coming to an end, but the age of the A2 supermiddleweight 600 has only just begun.