Monday 7 September 2020

Honda CBR600 vs. Kawasaki ZX-6R

Modern 600s offer the perfect compromise. More than enough power to get ya chucked in jail for excessive speeding yet running costs that aren't entirely out of the real world of yer average yob. Plenty of different Jap models available but, apart from a couple of quick blasts, most of my riding's been done on Honda and Kawasaki 600's.

It all started with one of the first Honda CBR600's. These more or less defined the breed, though the excessive plastic wasn't to many tastes I thought it a brilliant looking machine. Honda had long realised that the more extreme race replicas soon annoyed their riders with their lack of comfort, and the CBR600 had excellent ergonomics in contrast. The kind of machine you could sit on, feel instantly relaxed and ready to rock and roll. So awful are modern road conditions that no distractions can be tolerated.

This was back in 1988, the machine a year old with 9700 miles under its wheels. These models only had 80 horses and weighed about 410lbs, needed some revs to run well, but were about as good as 600's got back then. A 4-1 exhaust liberated an excess of noise and improved top speed from 140mph to 145mph, not an experience I'd willingly repeat. Not only did I have to buy ear-plugs but the suspension went all dangerous above 135mph.

Right out of the crate, the suspension was probably adequate - the glossy comics didn't complain too loudly, anyway. But a year's worth of wear, the previous owner a bit of a porker, had left them open to abuse from the larger bumps at low speeds and prone to fluttering in protest at speed even over apparently smooth roads. My favourite country lanes also turned up some handling horrors, the bars going from lock to lock when exiting bumpy bends at about 50mph.
 

Not too amusing but I soon became used to the bike and compared to my previous Z1000 it ran on rails, could be flicked about with hardly any effort and was a relaxed 120mph cruiser! Acceleration could do my vision in but I was always aware that the motor might end up wailing away - down to the notoriously slack Honda gearbox that wasn't really sorted until the last model!

The engine was one of those complex water-cooled mills that was best left alone apart from 1500 mile oil changes. The carbs needed a balance every 5000 miles or so but even when they were out the major downer was secondary vibes singing through the chassis rather than any noticeable diminution in outright performance.

These were tough motors, even the camchains could do 50000 miles. Thus, the bike stayed in my hands for four years, 67000 miles on the clock when I decided to trade in. A new camchain and tensioner at 42000 miles the only major expense. By the time the bike was traded in, top speed was down to a mere 135mph, fuel was 35mpg (compared to 45mpg when I bought the machine) and secondary vibes were particularly vile at 9000rpm.

The replacement was a nearly new 1992 CBR600. First impressions were of searing acceleration, mind numbing 155mph top speed and an ultra-precise gearbox. Handling wasn't as taut as my old one - I'd fitted a stronger shock and uprated fork springs - but it motored along superbly, making previously rough roads feel as if they'd been recently resurfaced! The twin discs were about twice as powerful, Honda calipers going pretty dire after 20000 miles (needing a rebuild every second pad change at 8000 miles).

Oddly, the engine demanded a full service every 6000 miles as well as the same frequent oil changes. Ignore the valves or carbs, acceleration turned all somnolent. Along with short-lived if excellent Metz's, the expenses soon piled up. Fuel was 30-40mpg, depending on acceleration and velocity. Performance was quite addictive, any excuse for a ride and always taking the longest route!

By 23000 miles the chassis was going off rapidly. The forks had always felt a bit marginal at the excessive velocities possible but by then the seals were dead and the damping AWOL. The rear shock did a perfect pogo-stick imitation once it overheated from excessive speed action. The handling finesse was totally lacking but the steel chassis combined with its clever geometry made sure the bike didn't go completely out of line.

A White-Power shock - multi-adjustable and re-buidable - soon sorted out the back end; much better than new! The forks needed a complete rebuild, fitted with heavier springs and the damping holes constricted. The bike was then racer taut, rumbling over low speed bumps but becoming very slick when the throttle was rolled open. New found angles of lean and speed through corners shocked my mates into submission. Not a cheap upgrade but well worth it.

At the same time, I was aware that the discs were in a bad way. Well, not just the discs, the calipers were all gummed up and reluctant to work precisely. The discs themselves had gone all thin, marked with many minor grooves... so bad that the pads lasted for less than 2000 miles. The cost of new bits likely to cause an heart attack, replacements from breakers were secured, replaced after the usual tussle with seized in components.

With the old 600 I'd preferred EBC pads, but the newer bike had better braking with Ferodos. The differences were minor but every little bit of edge helps and I found the Ferodos had a touch more feel and feedback; with a decent set of discs and calipers, lasted for as much as 5000 miles. The refurbished brakes weren't as good as when I bought the bike but just about up to the machine's brilliant lust for road speed.
 

Particularly memorable was a high speed trip through France, when the speedo rarely went below 120mph. The Honda really hammered along the autoroutes and wide, almost empty, A road equivalents. At one point, a rather brave Frog cop leapt out into the road, gesticulating wildly. By the time I'd realised he was there I was well past him, decided throttle to the stop for next couple of miles was the best reaction.
Didn't get booked, anyway!

By 30000 miles the top end was rattling away. The camchain was knicker elastic. One replacement later, the motor was back to its normal purring but didn't really want to rev right out in the taller gears. It was a minor rather than major problem, if someone bought the bike they probably wouldn't notice. But I worried over this lack of top end fidelity and had the bike serviced, plus new plugs, air-filter and carb inlet manifolds (which can crack as they age). No difference, so I decided it was just one of those things.

At 39000 miles the engine seized solid. Not amused, I was doing 95mph at the time and the skid shook the bike like a jumbo jet flailing with a failed engine, until I managed to get it together and pull in the clutch. The seizure was caused by loose big-ends rattling the pistons about, so finely honed the engineering that any minor bit of wear can cause massive failure. I had expected to do twice this mileage!

Pissed off, I went around the breakers searching for a replacement engine. Luckily, a lot of 125 graduates write off their 600's and a 1993 engine was found, fitted and enjoyed. Well, sort of, when something like this happens it always makes me a bit wary of the machine, as if it's jinxed.

Nevertheless, the final reading on the clock was 54000 miles, when the Honda was traded for a new ZX-6R in 1995. A toss up whether I went for another CBR600 or the Kawasaki, but as the latter sported more power and speed I was seduced away from the world's largest motorcycle manufacturer. Many weren't, the CBR600 remaining the top selling 600.

More sporting in appearance, the ZX was less comfortable in reality, though first impressions were favourable enough. No, it took an hour's hard riding to turn my arse to stone and my wrists to agony. The bike became less annoying after a couple of months, my body adapting to its chassis, though the seat remained a particularly skimpy item compared to the Honda's, especially annoying for pillions.

The chassis was more high tech, less forgiving but more precise than the CBR's. The frame was alloy rather than steel, though of a similar wraparound design. Take the plastic off, the Kawasaki looked a lot less well integrated with various bits and bobs tacked on without much thought. With about 160mph possible, any hint of malevolence in the chassis would've been much pronounced but the bike seemed to run better the more the speed was poured on; the twin ram-air ducts forcing extra power out of the engine when really illegal speed was indulged - the bike seemed to boomerang forward at about 125mph with a violence that the Honda couldn't match.

However, the Kawasaki turned in about 25mpg against the Honda's 35mpg when ridden flat out. Combined with the ZX's lack of comfort, the Honda was easily the better high speed tourer even though the Kawasaki was faster and better accelerating at the top end.

I preferred the Kawasaki's taut suspension but it went mushy after 20000 miles, some quite heavy weaving at the back and twitching at the front. In that state I wouldn't run the Metz's beyond 3000 miles, though previously I could manage 4000 miles. A similar upgrade to the Honda got the bike back on the pace. Valves and carbs could be left for 10000 miles without any apparent problems whilst I did the oil changes every 2000 miles. Compensated for the heavier fuel consumption.

Despite some wild riding, I never actually came off the Hondas. Not so with the Kawasaki. Such was the delivery of power that I found it a bit dodgy on wet roads, didn't take much effort to have the back wheel sliding away. One day in Central London, I gave her a handful and lost the back end completely! The bike would've slid down the road except that there were all these cages in the way.
 

Bouncing from car to car as I staggered off, quite a lot of damage was done! Not least to the Kawasaki's plastic, wheels and discs. That all added up to major expense and an insurance claim that must've had the assessor in tears! No way I was going to chance secondhand wheels or brakes, not with the ease with which the stock stuff cracked up in an accident. Whilst the Kawasaki was being repaired I blasted around on a cheap, early model CBR600. Felt really slow but was so comfortable I began to wonder why I bothered with the ZX. The Honda celebrated each year with a new owner, having done a grand total of 134400 miles when it came into my hands.

Amazing how some bikes can run and run, though no telling what had actually been done to the engine. The chassis had toughened up suspension, plus later discs and calipers, meaning it went where it was pointed and stopped nearly as well as the Kawasaki. What it lacked was the mind warping acceleration and full-on, balls out, top end speed. Still, I did 9000 miles, sold it for what I paid for it, and was getting a pretty amazing 50mpg.

Once repaired, the Kawasaki was a real ball to ride flat out everywhere, the only kind of speed when I failed to notice how bad was the riding position. Another 5000 miles of fun and games rolled by before the chassis began to give problems. Firstly, the swinging arm bearings went, causing some wild wobbles at 80mph! Being a suspicious and cynical soul, I also checked out the wheel and steering head bearings, all just about due for replacement. Whilst mucking around with the rear suspension linkages, some wear was noted here also. Not much fun doing all that work just to get back to where I started.

The 105hp motor was beginning to bellow out of the exhaust, which also rattled with loose bits of rotted baffling. Not fancying holing the pistons from running the engine too lean, I bought a Motad 4-1 and Spent an amusing weekend getting it to fit on - you basically needed three pairs of gorilla-like arms! The Motad gave no more power, as far as I could discern, but a very nice growl once past 8000 revs.

The fairing lowers were always a pain to put back on and I was hardly surprised when I managed to crack the plastic around one of the mounting holes. Superglue was the obvious answer and it actually worked for 400 miles when there was a mild bang; the small crack had turned into a bloody big one. Seven miles was all it took to end up with the fairing flapping around dangerously.

A back street hero did the plastic welding honours, which worked if you didn't mind the odd blob of plastic and lack of colour coordination. I did, so sanded those down and made with the spray can and a couple of trendy Performance Berk transfers (sick, I know, but they were free!).

By 31000 miles I was suffering from blowing front lights and reluctant starting. The battery wasn't willing to hold a charge, the excess voltage flowing through the electrical system. A new battery and used light sorted that. Or so I though, 300 miles later total ignition failure. The electronic igniter unit was dead meat. The breaker sold me a dud, and was reluctant to exchange it until I told him my brother was in the CID.

As 35000 miles closed in I got the feeling that the bike was running out of zest, the overall finish wasn't brilliant and the seat was now totally flat, the edges of the plastic cutting into my thighs. The big bruiser had definitely lost its edge and was perhaps close to needing some serious engine work. I didn't fancy paying out for that, so it was traded in for an import Honda CBR600 in 1998.

Compared to the somewhat tired ZX-6R, the new Honda was well on the pace, though I'm not sure it quite had the high speed zest of a new ZX. The handling was better, though, more precise and easier to throw through the bends.

Comparing the new Honda to the early one, the bike had come a long way, not least in the handling, gearbox action and engine smoothness. Comfort and cruising abilities were about the same (and much better than the ZX). However, owners of the early stuff need not despair - a suspension upgrade and later spec brakes can have the bikes on the pace even if they are 20mph down on top speed (my licence's long gone but you can get fake ones in the Smoke!). I would be wary about buying a high mileage ZX-6R but something recent should be a real buzz.

Geoff S.