Chances are, the last time you talked big-bore kits you were 16 years old, munching a saveloy and slurping a can of Shandy Bass outside the chip shop while you wondered if it was worth splashing out on a 65cc kit for your FS1-E.
Those heady days may have gone, but big-bore conversions are likely to be a topic of conversation again this year. This time, though, you’ll be in the pub talking about the modern equivalent of that FS1-E kit – Kawasaki’s decision to up the capacity of the ZX-6R by 37cc.
And the two questions you’ll probably be asking yourselves around the pub table are: Why did Kawasaki do it in the first place, and does it make any difference? Well, we can answer both after securing the world’s first ride on the 2002 bike weeks before anyone else.
So why has the firm bothered to break with a couple of decades of convention and finally break the 600 limit?
Well, firstly because it could. When the firm replaced the ZX-6R’s thick steel cylinder liners with much thinner aluminium plating in 2000, it was left with 2mm bigger bores. It then had to make them smaller again to ensure the capacity remained at 599cc. But now it has decided it might as well take full advantage of that extra 2mm to increase capacity to 636cc.
The engine cases and cylinder heads had to be re-designed to suit the bigger bores, but apart from that the engine is virtually the same – though the new barrels are different enough to stop you bolting them on to an existing ZX-6R.
The second reason is purely commercial. Though the changes take the ZX-6R out of the 600 class, the truth is there were few benefits for Kawasaki remaining in that class anyway. The 600cc limit was invented for racing (Kawasaki will continue to run its title-winning 600cc bike
in World Supersport this season) and the number of people who take ZX-6Rs on the track are dwarfed by those who use them for commuting, touring and real-world riding, where Kawasaki says " a slight boost in power and torque would be welcome " .
Ah, a " slight boost " . That works out at about 2bhp extra. So you know from the outset that the extra 37cc isn’t going to turn the ZX-6R into some kind of steroid-enhanced super-middleweight.
This is really a makeover rather than an all-new bike. Aside from the 40 minor engine mods, including a larger diameter gearshift shaft for " improved shift quality " , there are some suspension changes. The fork internals have been improved to give a smoother action, while new damping rates are aimed at improving steering feedback.
There are also more minor changes, like the new fairing stay, which means you no longer have the " H " frame blocking the view to the clocks. Or the fact that the front brake master cylinder has been moved to further clean up the cockpit and improve the view of the dash.
You could almost say that these alterations are little more than a blatant attempt to wring a little more life out of a seven-year-old design.
Except that you lot are still buying the ZX-6R (see story, page 27). It was the UK’s biggest-selling bike in January – albeit due to heavy discounting.
And though it’s not as cutting-edge as Yamaha’s R6 or Suzuki’s GSX-R600, it’s still likely to be at the front of any group of 600s due to a blistering turn of speed. While it does feel bigger than the R6, it can hardly be described as bus-like. And if you happen to know a road where you can turn the throttle all the way and keep it there for a long time (autobahns, for example) the 6R will leave not only 600s, but even bigger bikes in its wake.
So once again you ask: " Why 636? " Kawasaki’s public line is that the changes are simply to enhance your riding pleasure and make everything just that little bit easier. To find out whether that really is the case, we dived over to Holland, where local importers had managed to get their hands on the bike before they’d arrived in the UK. We also took a current ZX-6R with us for the world’s first comparison of the two back-to-back.
One thing is immediately obvious – these bikes aren’t mere siblings. They are virtually identical, apart from the " 636 " on the green bike’s fairing.
From the seat, things get a little easier. Though the riding positions and the highish, firm and generously wide seats are the same, you do notice the cleaner look of the cockpit without the " H " frame.
But when you buy a new model, you expect something that will really stand out in the crowd. This one doesn’t even stand out in a crowd of two.
I thumb the starter, listen to the familiar Kawasaki race of the engine on choke and the accompanying airbox rasp, and after giving it a bit of time to warm up, get out on the road.
Holland isn’t perhaps the first place that springs to mind when you think of going to the continent to ride a bike in February, but we’ve struck lucky with the weather and the roads. The sun is out and though temperatures are in low single-figures, the sight of clear blue skies always lifts every rider’s heart.
You imagine the Tarmac to be relentless miles of straight, dull dyke-topping. But the Dutch have managed to sneak a few wiggles in there and we go out of our way to find them.
First up is the new boy. And the sensation is… that you’re riding a Kawasaki ZX-6R. There’s plenty of go, but then the old bike had that. You have to really start feeling your way around the rev-counter to notice the difference. But it is there.
Right off the bottom of the rev-counter, the bike carburates cleanly. The old model isn’t bad, with relatively strong drive everywhere, but there’s a slight reluctance to pull at the bottom end of the range, while higher up, around the 7000rpm mark, there’s noticeable improvement in attitude, as if the bike suddenly decides it will play ball after all You don’t get that with the 636cc bike. There are no hiccups or dramas whatsoever. It starts to pull, it pulls some more, it keeps on pulling hard and then it pulls its hardest, all the way to the rev-limiter. Change gear and it does the same thing all over again.
But it hasn’t become bland. Sometimes a bike with a very smooth and even power delivery can seem like it isn’t doing much. The 636 isn’t one of them. At first, it seems the old bike is the stronger of the two. But as the kilometres clock up on the 636 and the engines get thoroughly warmed up, so the bigger bike begins to stretch its legs. Wind it on hard in first and it’ll just start to lift the front wheel as you get into the real power, even when you’re staying half-crouched over the bars. The older bike keeps its wheel firmly on the ground unless you sit up more. A small difference, sure, but an indication that there is plenty of grunt getting to the rear tyre.
What that means in practical terms is you get a smoother ride. Out of slow corners, the bike picks up the revs and gets going in a slightly easier way. You’re not waiting for the kick as it gets into its stride.
In side-by-side roll-on sprints, the new bike always wins, no matter what the revs are. The difference is greatest from the lowest speeds, with the large engine’s smoothness probably making more difference than the motor’s outright power.
The difference isn’t mind-blowing, though. It really is more of an extreme tidy-up than a step up to the next level of middleweight performance.
The rest of the package hasn’t been unsettled by the changes to the engine. The bike feels better-balanced than the old one going into corners, which is probably partly down to the new forks and partly to the Michelin Pilot Sport rubber the Dutch get instead of the Dunlop D207s fitted over here. You get more feedback and confidence on the new bike.
One thing that is totally unchanged is the braking. The old bike’s front set-up was almost scarily powerful. At MCN’s sports bike mega-test at Assen last year, we all noted that the ZX-6R possessed some of the best brakes of any road bike.
But, as the Pirelli adverts used to say, power is nothing without control – and the control is there. Early-model ZX-6Rs were criticised for wooden brakes. Newer ones consigned that to the history books. The power was backed up with a high level of feedback that let you control the amount of pressure you were putting on the front tyre accurately.
That is as true as ever for the new bike. If anything, the new fork internals have improved that, but in low temperatures you can only push so hard before you feel the tyre wanting to let go. In any event, it really needs testing on the track before you could really say if there is better control – we’re talking about on-the-limit differences here.
After a nice long run out on the bike, taking in some of Holland’s interestingly surfaced motorways as well as the twisty lanes we’ve managed to search out, the new 636 really shines. These are the kinds of roads Kawasaki clearly had in mind. Tighter, Alpine-style switchbacks would be better tackled on a sharper bike, and the same goes for race tracks. But out here the ZX-6R is king.
The motorways are smooth, but feature some deep depressions which really get softly-sprung cars wallowing – you can watch them bounce. On a hard-sprung bike you’d be launched into the air every time you came out of one. The 636 seems to have found just the right balance. There’s no wallowing, yet turn the speed on (watching out for the ever-increasing number of speed cameras) and things stay sane.
That pleasure doesn’t disappear when you get to the lanes. Where you might think you’d have to stop and stiffen things up on the fully adjustable suspension, nothing is needed.
The powerful brakes don’t overwhelm the standard set-up. And remember – this was already the fastest 600 out there. Now it’s even quicker so you’re arriving at corners a bit faster. It doesn’t matter. The brakes haul you down to speed, the forks cope without drama and you drop easily into the turn in the same way the old one did – quick and accurate, but not razor-sharp and twitchy.
Once you get into a flow, you can feel where the new engine is making more power. It is there in the bottom end, but it really builds in the middle, where a smooth drive means it’ll feel less than the speedo tells you. This is a bike that will be described as deceptively fast by many owners.
On a long journey, that deception will be very welcome. You’ll clock up the miles without noticing them rolling by as the Kawasaki’s generous proportions let you sit in comfort without troubling the gear pedal when you overtake or swoop through the corners. You can be lazy and it’ll let you get away with it, where other 600s will punish you with a reluctance to drive from lower down the rev range.
Strangely, given that Kawasaki insists the set-up is unchanged, the rear brake on the new bike seems to lack power. It feels like all you can do is give it a big stab and hope for the best. Rear brakes on sports bikes aren’t a big deal to most riders, of course, as most of the work is done up front. But in the rain the rear brake is very useful for keeping the bike balanced and improving stopping distances when you can’t really hammer the front. Hopefully, it’s just down to new pads.
That’s the only bluebottle in an otherwise tasty treacle.
With even the February weather unexpectedly playing ball, we’ve had the chance to really see how the new bike fares in the kind of conditions you’ll want to ride it in. And the answer is that it fares just fine.
Kawasaki, it seems, is reaching out to a slightly different corner of the 600-buying public. While the ZX-6R remains fast and superbly confident in the corners, it is moving towards a more all-round role.
It’s not about to turn into a ZZ-R600 and it remains more than capable of holding its own against the other 600s. However, on the road, more than ever it gives you a chance to cover big miles in far more comfort than race-bred rivals.
But the thing is, you already could with the existing bike. And the one before that. If you don’t want more than a 600 and need it to do everything – track days, touring and commuting – the ZX-6R is perfect. But that applies to the 1999 bike I’ve just sold as it does to the new one.
So has Kawasaki done enough to make the new bike stand out? That all depends on your wallet and how important it is to you to have the latest bike. It is better, but it is likely to cause a drop in the price of existing models as dealers clear the stocks. And that could be a better bargain.
We crossed from Harwich to the Hook of Holland on Stena Line’s High Speed Service, which takes a little over three-and-a-half hours. If you’re heading to Assen for the GP or WSB rounds, book early because it’s usually busy. The typical costs for a bike and rider in peak season, Friday to Monday, are £126 plus £26 for a pillion. Tel: 08705-707070. MCN is running trips to the Dutch GP and Assen WSB round this year. We’ll give you more details nearer the June 29 and September 8 race dates.
Thanks also to Pidcocks of Derby for the 2001 ZX-6R.