After 2000 miles on my new GPz500 I was well pissed off. My first impressions of the bike had been good. Riding from the dealer it had felt commendably smooth, stable and flickable. Within the constraints of running in revs, I could feel the promise of sixty horses waiting to belt along less than 400lbs of metal. I carefully ran the beast in, so it wasn't until 2000 miles that l was fully able to rev the balls off it. There just didn’t seem enough power to make it really accelerate, even if it went all the way up to an indicated 130mph without trauma.
The gearbox had become notchy, at low revs in top gear the bike made an awful clunking noise like the transmission was about to fall out of the engine cases, the tyres had lost their edge, the bike especially skittish on wet roads, and the front forks dived and twisted under heavy braking — I only weighed eleven stones; god knows what they would do if I was a more typical heavyweight biker.
l persevered. hoping that the 3000 mile dealer service would see things get better. They didn’t, the engine felt exactly the same as when it went in. If l hadn't seen the mechanic adjusting the valves myself I might have suspected they had just dumped the bike in the corner for a day and done nothing. I started looking at 600 fours, but another round of price increases put paid to that particular daydream.
At 4000 miles the engine became smoother and the bike started to move with grin inducing acceleration. By 5000 miles things had improved so far that rather than think about selling the bike, l was convinced I had a good 'un that i should hang on to for the next ten years! When I did my own oil change at 5000 miles and put in some top grade oil, even the slight remaining notchiness in the gearbox disappeared. The bike obviously needs a much longer running in period than the handbook suggests.
The GPz500 employs sixteen inch wheels that are almost perfectly matched to the steering geometry — at least on brand new OE tyres. The Jap Dunlops that the bike came with were fine for the first 1500 miles, then rapidly deteriorated until they were both dangerously inadequate at 5000 miles (when the rear was just legal). The 120/100x16 rear tyre is a real bastard to replace because of its odd size and few tyre manufacturers offer a recommended replacement, although i have seen bikes fitted with Metzs. On new tyres, the GPz is not twitchy. it is wonderfully flickable but still very stable in a straight line. On worn OE tyres, the front wheel shakes its head over bumps (although only once, thank god) and the rear weaves slightly on fast roads. On wet roads a worn front tyre can let the front wheel slip away without any warning, and then seems to have little inclination to regain its grip. This may help explain just why there are so many GPz500s advertised in breakers.
l was sure the tyres were at fault, because I effected a complete cure to the problem by fitting of a set of Avon radials, one of the few sets of tyres recommended for the bike. The fat, 140/80 rear only just fits into the swinging arm and looks very meaty indeed. The set cost £125 including fitting, which is more than many readers will be willing to pay for a whole bike, but in view of the lack of alternative rubber and the loss of money in trading the bike in for something bigger (the only other viable alternative) it’s money very well spent in my book.
Within yards of riding my re-shod Kawasaki, I was a happy man again, instilled with confidence from both the feeling of security emanating, once again, from the machine and years of riding Avon tyred bikes. Although leaning the bike over sharply wasn't quite as progressive as I would have liked (an initial impression that either faded with use or the tyres settling in) I felt able to really lean the bike over at absurd angles — contrary to reports in other magazines I've never experienced ground clearance problems (perhaps those journos ought to shed some of the five stone beer belly and give the GPz suspension an easier time) and nor do I consider the looks of the bike to be at all plain (cast your eyes at the all white job, morons).
Put very simply, if you buy a GPz500 insist on Avon radials as part of the deal. They are that good.
In fact, the tyres are ahead of both the engine power output and the chassis. Not that the frame or suspension are particularly bad. The Unitrack rear end is controlled by an adequate shock with only preload adjustment available (at least after you go out and buy a suitable spanner) that is still usable after 25000 miles and 18 months. The front forks are well damped but inadequately sprung - after 2000 miles it was far too easy to get them down on their stops and they twisted under heavy braking from the single disc. A fork brace helps here. Fork gaiters were fitted after 5000 miles and no problems with the seals have been experienced. I am so impressed with the rest of the bike, though, that within the next year I will be bunging on high quality forks and a new shock.
The square section frame is badly welded and badly designed in that it uses a bolted up section around the engine to allow it to be pulled out, but it is stiff and does have excellent steering geometry —- so I can live with it quite happily for the next decade or so. The swinging arm, also square section, has old fashioned chain adjusters that are the usual tedious pain to operate (although the toolkit does provide the means to loosen off the back wheel). but despite no signs of flex I shall soon be replacing it with an alloy job with eccentric adjusters.
The Unitrack linkages are perfectly exposed to the road dirt, so I cut up an old inner tube and riveted and Araldited it between the space between rear guard and swinging arm when I pulled the linkages apart at 6000 miles. There was no sign of wear, but a distinct lack of grease (as per swinging arm spindle and wheel spindles), so I smeared on a copious quantity of grease and reassembled. The result, still no wear with 25000 miles up.
With the Avons fitted, even when well worn, the bike can be used with equal ease as a fast motorway cruiser or back road hustler. The seat, peg and bar relationship is just about perfect for any kind of riding. In fact, the seat is the most comfortable I've experienced since a K & Q equipped Gold Wing I once borrowed. OK, with the suspension a bit dodgy it can rattle a bit over bumpy going, but I swear on the good book that I’ve never been able to lean a bike over so far before or cruise with such equanimity at ton plus speeds. On back roads I've seen off just-about everything from rabid LCs to newish hyperbikes.
Braking is about as good as you're going to get. The single front disc is wonderfully powerful and controllable, works without the slightest hesitation or worry in the wet, and once a fork brace was fitted to help out the front forks, just couldn't be faulted. The original pads lasted 13500 miles and I was so impressed with them that I stumped up for a pair of Kawasaki originals rather than venturing into the dubious delights of aftermarket suppliers. The rear SLS drum was equally excellent.
It is still on the original shoes, rod operated it has such excellent feedback that I’ve not yet locked up the back wheel, yet it provides more than adequate stopping power. Either brake can be applied mid corner without upsetting the machine. I really can’t think of any way of improving on the brakes — and the front's still on the original brake fluid!
If the riding position is the perfect compromise, there are a few niggles that upset me after paying £2700 for a bike. The neat fairing does nothing to protect my hands, my leather gloves are still soaked through in a downpour. Had Kawasaki fitted conventional bars instead of the cast alloy jobs, I would have lost four or five inches off each end by fitting narrow, flat bars, thus putting my hands out of the wet and cold. Equally annoying is the stock screen that fails to throw the air over my head. Easy enough to cure, i thought, fit a higher, flip-up screen. Very clever, at 90mph the wind blast deflects the screen downwards to the height of the original bit of plastic. Also, if the petrol tank was a few inches narrower it would have put my knees out of the wind blast. Oh well, can’t have everything. At least the seat height is very low, a factor with the large tank, that makes the rider feel right at home within a very short distance The bike can be ridden for more than 200 miles without worrying about filling the petrol tank or any discomfort from the riding position — and it can hold 100mph without any problems.
At such speed there was none of the annoying secondary vibes so prevalent on four cylinder machines. My initial impression of the machine was that it was a little rough at certain revs, but once the initial 5000 miles were over I either became so used to the machine that it no longer bothered me, or the engine became a real smoothy. I had assumed the handlebars had some kind of rubber mounting, but on disassembly (when l was trying to work out how to replace them with a more conventional set up) found that they were directly mounted to the yokes, so for a vertical twin the GPz really is smooth!
There is little that is stunning in the basic engine design. save that Kawasaki are the only factory to apply such concepts to a road going vertical twin. Based on the EN450, itself half a GPz900R, I really only have two complaints. The camchain should have been placed on the end of the crank rather than in the middle — to be fair, Kawasaki’s camchain and auto-tensioner design is one of the better and I expect long life. The eight valve head has screw and locknut adjusters for valve clearance, despite being served by twin cams, instead of shims which could have been left alone for 20000 plus miles.
Maintenance, as far as i am concerned, consists of changing the oil every 1500 miles and giving the bike to a dealer every 10000 miles for a major service (£75). Getting at the valves to adjust them means a major disassembly job — I couldn’t even get the petrol pipes off, let alone clear some of the plumbing out of the way. At the last service the dealer reported that everything was in good order, so this philosophy seems to work OK. I have great faith in water cooling and regular oil changes.
The bottom end design goes back to the days of Suzuki's mid seventies GS400. with pistons that move up and down out of phase and a single, gear driven (thank god) balance shaft. The GPz engine always feels like it's working unlike the GS, and this is a plus point in my view. Primary drive is via long lasting gears, to a light, predictable clutch and a six speed box. I would have been quite happy with four or even three gears.
Had Kawasaki not designed the gearbox so that only first or neutral could be selected from a standstill, l would've quite happily pulled off in second up quite steep hills. My only complaint was that even with a high mileage up the bike couldn’t be run down to 1000rpm tickover in sixth — below 1750mm the transmission crunched nastily, perhaps a leftover from the EN450 engine which in being belt driven did not need to pay so much attention to the cush drive design.
The GPz is fitted with an O-ring chain that needed minor adjustments for the first 2000 miles and then settled in quite happily, requiring attention only every 1500 miles if given a quick spray every 500 miles. Unfortunately, chain spray technology (or lack thereof) still means that the back and gets plastered in crud. If I could buy a full chainguard enclosure I would. The original chain lasted for 15000 miles. the second is still going strong — I was not amused at the effort involved in fitting endless chains.
The new EN500 Custom has belt drive, as does the GPz305, so it’s a pity that Kawasaki can't extend this design philosophy to the GPz, rather than just changing the paint colour every year. A proper design of belt drive would get rid of the last bit of ancient design on modern motorcycles and also save some weight. I don't like the weight or handling penalties involved in shaft drive bikes.
One magazine had the absurd notion that the GPz500 was buzzy. I suppose any engine that is willing to rev to 11000rpm can be described as buzzy. if you insist on misusing the English language In fact, the 500 is a typical, schizoid vertical twin. Below 6000mm it produces enough torque to waltz along on minimal throttle openings in fifth or sixth gear, and will run along at 70mph all day without a care in the world. Used thus, the bike returns 70 to 75mpg.
However, such fun can be had by revving the engine beyond 6000rpm that it’s unlikely that any owner will achieve such economy. The exhaust takes on a really delightful howl and the power pours in. Harshly applied in the lower gears it’s possible to get the front wheel a foot off the ground, but no more, such is the steering geometry of the Kwak that you really have to push it to impress the LC brigade with wheelies. The power is a fraction short of the arm wrenching, vision distorting nature of big fours but quite addictive in use of excess revs and low gears. As soon as funds provide, I will fit a stainless steel 2—1 Motad exhaust, which as well as hopefully liberating an extra bit of urge will save some mass into the bargain. It is definitely a fun bike to ride, but one quite hard to get into serious trouble upon.
I average somewhere between 55 and 65mpg, although it’s possible to go down to 46mpg. The engine doesn’t like unleaded fuel at all, dropping consumption to a mere 40mpg and making the engine run especially rough. I tried it once and never again. Oil consumption was negligible between oil changes. although there was a very slight oil leak where the oil filter site which was cured at the last fllter swap.
Controls are common to many other Kawa models. The push to cancel indicators are a great idea once you become used to them. The headlight has an excellent main beam, adequate for fast work on unlit back roads, although the dip beam isn't quite up to that standard. The mirrors are perfectly mounted for hitting car mirrors when you filter through traffic but give an adequate rearwards vision, although at low revs they can blur a little.
Finish on the cycle parts is excellent - l have one of the all white bikes, a colour which perfectly complements the lines of fairing, tank and side panels. Mudguards, panels and seat base are all plastic which stops any worries about rust. Every 1000 miles, or so, the wheels need a quick polish to stop them going white and the bike gets sprayed with Gunk (don’t bother with the foam version, it doesn’t work very well) and jet washed. It is still in excellent condition now, despite being ridden in all kinds of weathers. I dumped the belly pan as i like to see an engine and it saved a bit of weight. The stock exhausts are still serviceable and I suspect will last about three years.
I have done no pillion work so can’t comment on that aspect. I do, however, suspect that anyone weighing over 12 stones who rides the bike solo will push the capabilities of the suspension to its limits, and that any three year old bike will need a new set, preferably of superior specification, to maintain the excellent standard of handling provided by the machine from new. Bear that in mind when considering if you can afford one.
I do feel, that for a modern motorcycle, Kawasaki have not paid enough attention to minor details and if they expended a little effort could get the dry weight down to around 300lbs whilst retaining the same motor. After all, Yamaha produce a 600cc four that weighs in at under 400lbs. i also feel that although it is a very practical machine, more attention could have been given to weather protection and access to the valve gear. Overall, though, I am mightily impressed with the bike and intend to improve it as funds allow, sticking with it until the engine gives signs of expiring.
It’s a little too early to comment on engine longevity, but I have seen examples with over 50000 miles on the clock already that seem in good shape. I am hoping for at least 100000 miles before i have to do anything major to the motor. The engine presently exudes a feeling of unburstability and seems to have lost none of its edge. I look forward to many more happy years.
Dick Lucas