Suzuki GS 750EZ

What do you do for an encore when you already build a motorcycle that's the best thing in its class? Well, the radical approach would be to throw that design in the scrap-head and roll out an all-new one. Or you could go to the other extreme and simply rearrange the pinstripes before running the same old bike by the public one more time. Probably, though, the most intelligent strategy is to stick with that same basic motorcycle, all right, but to improve it by rectifying anything that had caused problems or provoked criticism.

Judging by those parameters, Suzuki seems to have made the right moves with its new 750-class flagship. Because that company's 1982 GS750EZ is essentially the same motorcycle as the 1981 GS750EX-a bike hailed by most critics as the best all-around 750 on the market—except that it now boasts a number of refinements and detail changes, most of them in response to complaints about last year's bike. As a result, Suzuki has extruded a significantly better motorcycle out of the one that already was acknowledged as The Best.

Not that the '81 GS750 gave anyone much to grouse about. It was, after all, equal to or better than its competition in virtually every imaginable category of performance (as verified in Cycle Guide's 750 Comparison Test, June 1981 issue), and it offered a range of versatility that the others couldn't match. Regardless of whether it was involved in ten-tenths horizon-tilting on a twisty backroad or relaxed vertical cruising on the Superslab or just plain day-to-day lunchbox-toting around town, the GS750E always seemed to be doing precisely what it liked best.

Still, some riders did find fault with it, even if they had to pick a few nits to do so. Take engine performance, for instance: The Suzuki, they whined, was not the hottest 750 around, pointing to the Yamaha 750 Seca's capability of blitzing the quarter-mile a few hundredths of a second more quickly than the GS. But unless Yamaha has secretly pumped up the Seca's power output for 1982, that situation seems likely to change. Because every GS750EZ rolls off of the assembly line armed with considerably more firepower in its 16-valve, double-cam motor - about a quarter of a second's worth, to be more precise.

What this means is that the Z-model GS is a 12-second-flat 750, one that could even dip into the high elevens if the strip conditions are any better than those we encountered at Orange County International's slick start-line area (left by a Funny-Car National run there the day before) when we recorded our 12.011-second best E.T. What's more, the engine's newfound thunder has not come at the noticeable expense of the healthy low-end and midrange torque that made last year's bike so pleasant to ride when it was not in full-on dragrace mode.

That's intoxicating, leading-edge performance, indeed, for a 750, but what's more impressive is that so much additional power (a quarter of a second in a quarter of a mile is a bunch) has resulted from only three relatively minor engine changes. The intake cam was ground with one more millimeter of lift, and it now bumps the valves open six degrees sooner and lets them bang shut six degrees later. And complementing this rudimentary hot-rodding trick is a recalibrated ignition curve that initially retards the timing two degrees (for a smoother idle with the more-radical cam) but adds five degrees at full advance (for maximum power production).

There are a few differences of lesser significance on the new engine, one being the use of hex-head bolts to secure the cases and covers rather than the traditional, easily bunged-up Phillips-head screws. The sole cosmetic change is that the little rectangular "beauty covers" on the outer ends of each cambox are now black-and-polished alloy castings rather than chrome-plated sheet-metal stampings. And electrically speaking, the Z has a permanent-magnet starter motor that's claimed to out-crank and outlive the electromagnetic motor used previously.

Otherwise, the engine remains just as it was in '81. It retains Suzuki's patented TSCC (Twin Swirl Combustion Chamber), four-valve-per-cylinder configuration with forked cam followers that allow each lobe to open two valves. The real-world advantage of this design (also used on the GS1100), however, is that the followers make it easy for the owner to perform his own valve-lash adjustments, whereas conventional shim-and-bucket arrangements call for an assortment of tools and shims that most people just don't have.

Engine-wise, the GS750 actually shares quite a lot with the GS1100, which speaks well for its reliability potential, but there's an important difference in the lower-end construction: The 1100 uses a built-up crankshaft with roller bearings on the main journals and con-rod big ends, while the 750 has a one-piece forged crank with plain bearings all around. And although roller-bearing cranks are fractionally more efficient for maximum-performance applications, a plain-bearing bottom-end is at least as durable, not to mention being considerably less expensive to manufacture, as well as to repair or replace.

Plain-bearing engines also tend to run a bit more smoothly, which may account for some of the GS750EZ's exceptionally low level of vibration. At moderate rpm the rider is only remotely aware of the motor's presence just inches from his knees; and it takes an excursion up into the tachometer's twilight zone before any tingles show up in the grips and pegs that could be considered even mildly annoying.

Smoothly, in fact, best describes the way in which the GS750 engine does just about everything. It pulls smoothly from just above idle all the way up to its 9500-rpm redline; it makes the transition smoothly into the really productive part of the powerband at around 6000 rpm; and it snicks through the gears smoothly, completing each change with the short-throw, low-effort precision that has become a hallmark of Suzuki gearboxes in recent years.

The only way, really, in which the engine is not ultra-smooth is in the way it behaves when the throttle is switched from fully closed to barely cracked-open and vice-versa. The reaction to those minimal changes is simply too abrupt; and that oversensitivity of the Mikuni CV carbs, magnified by a bit of excess lash in the driveline, tends to produce some minor but nonetheless bothersome lurching as you try to regulate the rpm at these smallish throttle openings.

This is one specific complaint about the GS750 (and GS1100, as well) that has not been adequately dealt with by Suzuki ever since the 1980 model year. The same could be said about a particular shortcoming of the chassis, that being the relatively limited cornering clearance. The combination of low-slung engine and soft suspension makes it easier to bang the usual undercarriage bits - stands, pegs and exhaust hardware—on the GS than on most comparable bikes when the cornering gets hot and heavy.

Suzuki's reluctance to remedy this condition, however, is a lot more understandable than is the throttle-response problem. Because significantly increasing the cornering clearance on this bike would have entailed either a major chassis rethink or a considerable firming-up of the springing and damping rates to reduce suspension compression during hard cornering. And since the former would be prohibitively expensive and the latter would ruin the most luxurious ride in the 750 class, the best alternative (and the one Suzuki chose) is simply to leave well-enough alone.

Besides, despite its Rolls-Royce ride, the GS750EZ handles with marvelous ease and agility right up until the sparks fly. And at that point, the bike has been banked over at a respectable if not incredible angle, especially if the spring preload on the Showa damping-adjustable shocks is on its highest setting and the fork's static air pressure is up around 10 to 12 psi. A hard-charging canyon racer will, no doubt, yearn for more leanability, as will anyone roadracing the GS in box-stock classes—in which case, removing the centerstand will net some more of that precious banking angle. But for 95 percent of GS750EZ riders, the standard cornering clearance will be more than adequate 99 percent of the time.

Actually, the springing and damping rates at the front of the '82 bike are slightly softer than on the '81; in fact, the entire fork is different, the leading-axle fork with its two-rate springs having been exchanged for an inline-axle type with triple-rate springs. But that softening doesn't seem to have hurt the handling at all; and there is 8mm additional front wheel trail afforded by the new fork geometry that makes the GS even steadier and more confidence-inspiring than it was before, no matter if it's barreling down the straight and narrow or bending around the tight and twisty.

Anyone who's ever ridden an '80 or '81 GS750 and tries the new bike will, however, notice a small improvement in what was already the finest ride in the class. The fork absorbs little chops and ripples more readily, and the big bumps melt away under the GS as though they were optical illusions instead of concrete realities. And most of what does get past the fork and shocks is soaked up by one of the finest seats in the business. The only time the ride feels even the least bit harsh is over smallish, abrupt bumps, like the expansion joints of some concrete-slab highways. There's a bit of choppiness then, felt mostly through the rear; but perhaps this is more noticeable only because the front suspension is so efficient over the same undulations.

Nobody, of course, asked for a smoother ride after trying last year's 750, but many did clamour for a more reasonable handlebar, something to replace the super-long, radically swept-back tiller-style bar and the bolt-upright riding position it forced. And they got their wish, for the Z-model has a bar with a much less-dramatic rearward sweep that lets the rider cant his torso forward ever so slightly. Not only does this allow a better seating position for improved long-ride comfort, it feels more natural and confidence-inspiring when you're play racing on your favourite backroad.

Suzuki also was bombarded with impassioned pleas to do away with the bulky-looking rectangular headlight and the bulbous instrument package that went along with it in favour of something more conventional. And the company's response to that input from riders and dealers is apparent in the round halogen headlight and traditional-style instrumentation on the Z-model. And in the process, the dashboard acquired a handy oil-temperature gauge on the right side to balance the fuel gauge on the left. But more important, the overall effect of this new hardware is to make the new 750 look a lot lighter than the old one. In truth, the Z-model's weight is down just a bit - six pounds - some of it due to the new light/instrument package; but the bulk of it is because the new front fork assembly is considerably lighter.

That fork lightness seems all the more impressive when you consider that its overall weight includes the hydraulic anti-dive mechanism that's built onto each slider leg. The purpose of the anti-dive is to keep the front suspension from compressing so dramatically during hard braking, a trick it attempts to do by virtually closing off the flow of damping oil whenever the front brake lever is squeezed. The idea, of course, is to prevent the steering geometry from being quickened due to front-end dive, thus allowing the bike to remain much more stable during hard stopping - a time in which it needs all the stability it can get.

But while the anti-dive might not weigh a lot, it doesn't really do a lot, either. The truth is that it doesn't prevent front-end dive as much as it merely slows it somewhat. The fork will still compress just about as far during most braking situations as it would have without the anti-dive, but it just takes a little bit longer to do it. So even though you end up with practically the same quickened geometry you would have without the anti-dive, that slower transition gives the rider a little more time - even if it's only a fraction of a second - to adjust to that change.

That fact alone qualifies the anti-dive as a worthwhile feature, even if it could stand some additional development. And that pretty well sums up the GS750EZ as a complete motorcycle, as well, for all of its model-year refinements are worthwhile ones that have made an exceptional motorcycle substantially better, even though there still is room for improvement.

But is it still the best? Common sense says that it ought to be, since the other manufacturers have not changed their comparable models as much as Suzuki has changed the GS. But because we haven't actually tested those other new 750 fours, we can't be positive that the Suzuki will retain its King-Of-The-Hill status for 1982. Especially not when a near-revolutionary machine like Honda's all-new 750 vee-four is looming just over the horizon.

But those questions are impossible to answer right now. And until someone actually does come along with a 750 of any configuration that is faster, smoother, more comfortable, more versatile and better-handling, the GS750EZ is The Class Act in the 750 class. It's a case, in fact, of the encore being better than the original performance.