Suzuki GS 850G
Road Test PLENTY. OF THE MOTORCYCLES WE TEST You may be thinking, as we did, that Suzuki should have developed the GS850 from the GS1000 instead of basing it on the GS750. Shaft-drive machines do carry more weight than their chain-gang brethren and the lighter, more muscular, larger-displacement engine would seem to have been a better starting point. Suzuki had good reasons for the choice they made. One was that many insurance actuaries recoil in horror from all motorcycles with engine displacements above 900 cubic centimeters, especially those owned by young men Viewed in that light Suzukis decision to stretch the GS750 makes sense. There's more than the expense of manufacturing in the ultimate cost of motorcycle ownership, and Suzuki didn't want to price the new shaftie beyond the typical young man's reach. Another reason for using the GS750. rather than the newer GS1000. was that when the decision had to be made, the latter was still very new. White the 1000 looked good in pre-production testing and while there was no reason to doubt the 1000's reliability, the GS750 had been in service long enough to have absolutely proven itself. Further, the GS750 engine actually was—and is—stronger. Suzuki's engineers pared weight out of the GS1000 in hundreds of small slices, taking it even from the main bearing supports and crank cheeks. They now know the paring wasn't overdone, but that hadn't Suzuki's creative urges obviously did find an outlet when the GS850's final-drive layout was being designed. The problem is to turn the drive 90 degrees behind the transmission and direct it back to a BMW-esque gear housing at the rear wheel hub. And to provide a drive-shock cushion to protect the whole drive tram, which will be more tightly tied together than it is when a chain and sprockets aro used. Others have resorted to transfer shafts and gears behind the transmission and/or separate bevel gear housings. But Suzuki grafted the necessary additions onto their existing shafts, taking advantage of available width and holding to the bare minimum the number of gears involved in transmitting power to the wheel. The bevels are placed about where the GS750 has a sprocket but are within the widened transmission cases. It must be stressed here that the width we're talking about is just dead space behind decorative covers in the chain-drive Suzukis; there has been no increase in the distance the rider has to straddle with his feet. Indeed, the only obvious external difference between the GS750 and GS850 is that the tetter's rear transmission wall is blank instead of having a chain cavity. Nothing shows outside but the flanged attachment for the drive shaft's U-joint. which is of the conventional automotive "Hooke" type rather than the more expensive constant-velocity coupling. Suzuki's choice of U-jomts may partly account for the elaborate system of elastic couplings in the drive train. The angular displacement of the Hooke-type joint's yoke produces cyclic speed changes In the rotating shaft, when the joint is working at an angle, and this can generate a torsional vibration. Suzuki may have had that in mind when the GS850 was given rubber-loaded bushings between its final drive gears and rear wheel, a spring-loaded face-cam cushion between clutch and transmission, and the usual set of shock-cushioning springs in the clutch itself. The arrangement works: there is no appreciable transmission-related vibra-tion-and very little of the drive-train lash we have all come to know and loathe in certain other motorcycles, mostly Yama-has in this regard. Another point at which the GS850 is a lot better than most Japanese-made machines is its shifting action. Any of the present generation of motorcycles will stir their gears in reasonably orderly fashion if you apply a firm toe at the change lever The Suzuki needs nothing but a light dab and snicks from one gear to another so smoothly its rider has to get really sloppy to miss shifts. This is one of the little things that makes the GS850 such a pleasure to ride. We like the shift action so well we're almost willing to approve of Suzuki's trendy digital gear indicator lights, which display in bright red numbers the gear you've engaged. These numbers used to be formed by LEDs (Light Emitting Di-cvcodes) but Suzuki has switched to regular filament-type bulbs behind red-tinted glass. The neutral indicator is still a green light, and it's still easier to get the bulb glowing than it is to actually get the transmission into neutral after the bike has stopped. It's easy to predict which ot the gear indicator light bulbs will be the first to burn out. Somehow, perhaps with the added displacement and GS1000 cams, Suzuki has made the 750 engine into a solid low-speed lugger in the GS850. We still haven't devised a satisfactory means of hooking shaft-drive motorcycles to the One of the more amazing things about the GS850 is that it is able to gather up a hurry when you want one. The bike is not only heavy for an 850, but heavy in the absolute sense. Top up its tank with fuel and it registers just over 600 pounds on a certified scale. Yet the GS850 ran through the speed lights during our quarter-mile testing at 104.77 mph, which is motoring right along. Its weight showed only in the relatively slow elapsed time, a wink under 13 seconds, which reflected a sluggishness during the first 20 feet more than any reluctance about gathering speed once it was truly moving. We know a 600-pound 850 shouldn't have Superbike acceleration, especially when it's pulling tali gearing, but the GS850 does. It's only about as fast as a good 500 getting across the tirst halt ot an intersection, but from there on it feels like a 1000. The GS850's suspension is a mixture of GS750 and GS1000 hardware. Its fork differs from that on the 750 only in having tubes that are 20mm longer, and the springs and air valves come directly from the GS1000. The rear shocks, which have four-stage adjustable rebound damping, are from the 1000 but carry different coil springs. Suzuki does not supply the pump and air gauge you sometimes get with a GS1000 to set the GS850's air-fork pressures. They provide a dial-type air gauge and instructions about how much pressure you should use in the fork tubes. They should include their very best wishes because that's the least you'll need when you arrive at a service station ready to put some more air in the fork. We found that adjusting the fork air pressure was a very difficult job without the GS1000 tool. It's easy to get the caps off the little valve stems (our test bike lost all its pressure when ridden with the caps off) and you don't need a special air chuck. But the quickest jab with the chuck we could manage put the pressure at 30 pounds per square inch and on most tries we sent it beyond the gauge's 40 psi scale. We then learned to just tap at the valve stem to bleed off pressure—and found that each quick tap was worth a four psi pressure drop. We also discovered that merely checking the pressure with the gauge reduced the pressure by about two psi. It wasn't easy to fiddle the pressure where we wanted it. The only reason this adjustment won't be a btg problem tor GS850 owners is that they won't have to do it otten. For all practical purposes, it's purely a ride-height adjustment. Owners will lind it useful in compensating tor the weight ot a big windshield fairing, and the spring-sag that comes with many mites of riding. We found no difference in ride with fork pressures varied between zero and 30 psi. and onty small variations in handling (at cornering speeds somewhat more lurid than the sane motorcyclist would enjoy). The usual adjustable lower spring collar is there and. as usual, it sets only the bike's rear ride height. You crank up preload if you're going to carry a passenger or it you want more cornering clearance. The other, less familiar adjustment is in the shocks' rebound damping; this one is made by turning the knurled collars under the rubber weather boots just below the upper shock eyes. And on some surfaces there is no perceptible difference between "1" (the softest setting) and "4" (full-resistance). One stretch ot nde-quai-ity test road we use has a wavy surface, with about 10 feet between crests and a couple of inches from crest to trough. On that road the GS850's ride did not change when we ran Ihrough the range of damper settings. And the ride was good. Those undulations send most motorcycles into a fierce hobby-horse pitching when traveled at 50 mph; the GS850 only nodded going across them. The damper adjustment did make a difference on choppy surfaces (i.e. cracked, patched and pitted pavement) and in the GS850's cornering behavior. Specifically, the higher-number settings felt like compression damping stiffness. Apparently, lots of sharp ripples cause the dampers to pump down, effectively stiffening the springs and making the suspension more harsh. This effect was felt when cruising along, riding solo, on rough roads, and it made the GS850 chattery when cornering fast on smooth surfaces. Both conditions disappeared when the damper resistance was reduced. The IRC "Grand High Speed" tires seem to cope wilh the load extremely well, and only the intimidating thought of what it might be like to wrestle 600 pounds of sliding motorcycle acts to keep one's enthusiasm in check. You just know that if so much mass gets out of control, it's going to stay beyond control a long, exciting time. Otherwise.the GS850 will let you play canyon-racer all you like, or at least as much as you think you can get away with. The GS850 doesn't (perhaps due to its sheer weight) display the typical shaft-drive bike's power-on/power-off attitude. Evaluation of braking performance has been changed by the introduction of hydraulics and discs into motorcycling. Back in the bad old days of drum-braked big bikes, stopping power was a sometime thing. But sheer braking force almost never is lacking with discs, especially when-as is the case with the GS850-you have a dual-front, all-disc system. So you think in terms of controllability, the tire/road connection, and whether the Motorcyclists do not live by performance atone. It's ail very well to wax eloquent over power and handling; those things don't mean much in a bike with a seat so uncomfortable that you can't ride it without getting an enormous pain in the expression. Here, too. the GS850 has been blessed Suzuki and one of its suppliers, the Correct Seat Company, also of iackel Source Cycle magazine 1979 |
1979-80年Suzuki GS 850G
2013/7/31 8:55:00