Suzuki Gs850

SUZUKI GS850

CYCLE WORLD TEST

Having learned with the two-strokes and rotary that people will only beat a path to the dealers' door if the better mousetrap is what people want, Suzuki has developed the successful GS street bikes. First there was the powerful GS750 dohc Four, followed by the GS550 Four, GS400 Twin and then the lithe GS1000 Superbike. ignition but the system works, is easy to repair if something goes wrong and it’s inexpensive. There are also aftermarket electronic ignition systems available for those who want them. Next is the 200 watt alternator w hich is marginal for heavy use. Many of the Japanese touring bikes have 300 watt alternators. Adding a few options, particularly high wattage electric riding suits to the 850 could overtax the system.

Now there's the GS850.

It doesn't have the power of the 1000. It doesn't have the handling of the 750. It has shaft drive.

Except for the shaft, the 850 is built from GS750 and 1000 parts, some modified where needed. And there are numerous refinements in the design befitting a touring bike. Things such as the 5.8 gal. gas tank, dual horns, extra wide seat and higher rate rear springs.

Front forks are identical to those on the GS1000, including the air adjustments, spring rate and damping. The cast alloy front wheel comes from the GS1000E, while the 17-in. rear wheel is a new design to match the shaft drive. Rear suspension is basically the same as the thousand, with four-way adjustable rebound damping, plus the spring rate is 5 lb./in. higher for the 850 which weighs 51 lb. more than the base GS1000.

Frame dimensions are a mixture of 750 and 1000, the front coming from the 750 and the rear section coming from the 1000. That means fairings which will mount to the 750 will mount to the 850, while any saddlebags or racks for the 1000 will work with the 850.

There are slight frame differences. With 28° rake, the front end is Io steeper than the 750 but the same as the 1000. Because of the new swing arm needed to house the driveshaft, the wheelbase is 59.75 in. or an inch longer than that of the 750 and 1000. Of course the swing arm pivot is different, modified to accept the driveshaft and swinging on a pair of tapered rollers.

The engine, for the most part, is based on the GS750, not the GS1000. When Suzuki officials explain that 750cc bikes are more popular than 1000s. there is no direct competition for an 850 as opposed to a 1000 and that insurance rates for lOOOcc bikes are exorbitant, the engine size begins to make sense. The same roller bearing crank used in the 750 is used in the GS850, providing the 56.4mm stroke. At 69mm bore is 4mm larger than the 750 which yields an 843cc displacement. Some engine parts have been changed.

Because the 850 was to be a touring bike, not a high performance machine, the engine was slightly detuned, as compared to the 750. Cams are from the 1000 which have less duration than the 750 cams and provide more mid-range power with less peak horsepower. The difference is 4" less duration on intake and 8° less on exhaust. Intake lift is 0.06mm more than the 750 cam w hile exhaust lift is 0.04mm more, all in the interests of mid-range power. Although the EPA may squawk, cams are interchangeable between the 750, 850 and 1000, so more peak power can be made available from the 850. though hardly needed.

Carburetion is the 26mm Mikunis also used on the 750 and 1000. When the thousand was introduced, Suzuki engineers said constant vacuum carbs would be a better choice for use on a touring bike but the conventional Mikunis were used on the 1000 for quick throttle response. Now comes the 850, still with conventional Mikunis. The only shortcomings are somewhat stiff return springs which make for tiring touring without a Twist-Assist or similar device, and abominable cold running performance.

Even in the moderate coastal California climate the Suzuki required full choke for starts and wouldn’t run without choke until the engine had run 10 minutes. Getting the engine to continue running 10 minutes is something of a chore and demands careful attention. Suzuki engineers tell us the carburetors have been carefully set to meet emission standards. So have the carburetors on other motorcycles which run better cold.

Two other engine details are worth noting. The ignition on the 850 is the same battery and points system used on the 750 and 1Ó00. It may not sound as impressive as anv of the modern varieties of electronic

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At least Suzuki has retained a kickstarter on the 850 as well as using a permanent magnet alternator which can start a bike even with a dead battery.

Once power has been generated and transferred to the clutch, the changes begin. Behind the innermost plate in the clutch is a wave washer and circlip, designed for smoother clutch engagement. Clutch size and design, otherwise, is like the 750 with the same coil spring shock absorbers to help damp shock loads.

A second damper on the left end of the transmission input shaft is more unusual. There’s actually a shaft within a shaft, the center shaft splined to a three-pronged outer piece which is spring loaded against a cam-like receptacle. The entire unit is damper, absorbing shock loads by having the male prongs ride up the cam-shaped ridges of the receiving unit while both pushed together with the coil spring. The concept is the same as for the shock absorbers used on Velocette primary drives, however the design is different. A rubber cush drive between the final drive unit and the rear wheel completes the damping arrangement in the drivetrain. With three dampers, drivetrain slack is minimized, Suzuki claims.

From the transmission input shaft damper the power runs through the gears to the mainshaft and through bevel gears on the left end of the mainshaft to driveshaft. Each set of bevel gears is held in place w ith a pair of tapered roller bearings for a total of six tapered rollers in system w hich helps account for part of weight difference between the 1000 and 850.

Other features add more weight. Instruments are a mixture of GS1000 and smaller GS models including the gauge of the thousand and the center idiot light pod of the smaller Suzukis. There have been refinements. The gas gauge sender has been reshaped to provide more accurate information. Used to be Suzuki gas gauge would read empty when the tank was half full. The new' system better, but not perfect. Now the gauge reads empty when the tank is empty but reads 3T full w hen the tank is half full.

Previous Suzukis used light emitting odes to show which gear the bike was But the LED display was so dim the numbers weren’t readable in daylight. After looking at all the LED units available, Suzuki decided to use individual tungsten lights to display the gear numbers. result is an indicator which is readable day or night. The improvement will be used on all new Suzukis.

Suzuki's First Shaft Drive Mixes the Suspension of the GS1000 With an Enlarged 750 Motor and Ends Up an Excellent Touring Machine

Instrument lighting is still red. Opinion around the office is divided on the color, most riders finding it acceptable and one complaining instruments are harder to read at night than those on bikes with green indicator lights. Could be the brightness. too.

Gone are the separate ke\s for ignition and gas cap. The removable rectangular gas cap. offset to the right of center on the tank, now is operated with the same kev w hich controls ignition and seat lock. And the fork can still be locked at the ignition switch, a definite plus. Just behind the key is a rubber pad covering the center of the handlebars. A similar pad was first seen on BMW's last year and didn't offer any real benefit. It isn't any more useful on the Suzuki, although the pad is smaller on the Suzuki and not so easilv removable.

Handlebars are the same tiller-shape as on the other Suzukis but extend higher. The bars bend back far enough so as not to remind the rider of the extra-long gas tank. The touring guv on staff wanted the bars angled down more at the ends while the sport guvs wanted the bars farther forward. Shows how compromise works.

Controls are standard Suzuki, which is to say very good, plus the addition of a turn signal canceller, same as the GS1000E. There's still a vestigial light switch, just waiting for an anxious owner to pull the

plastic tip. trim off a tiny plastic pin and reinstal 1 the tip on the switch which will then work. It's nice to have, even if most people will never use it. The turn signal cancellers work beautifullv. better than those on the Yamaha. Only difference is that the Yamaha requires too much distance to cancel while the Suzuki is spot on with most riders. To cancel the Yamaha signals manuallv. the lever is pushed in. while on the Suzuki the lever is pushed down. No big.

Unquestionably the worst feature on the Suzuki is the clutch/ignition interlock. The starter w ill not work unless the clutch is pulled in. even if the transmission is in neutral. Suzuki wanted to use a svstem w hich allows the starter to work when the transmission is in neutral or when the clutch is pulled in but it turns out Honda has a patent on that system. The problem is aggravated by the cold-blooded nature of the 850 which would benefit from careful choke control if a third hand could reach the choke knob, conveniently placed on the steering head.

Like Honda. Suzuki has been experimenting with mirrors, living to reduce the vibration level, first Suzuki rubber mounted the mirrors which reduced some v ibration. Then weights were added to the mirror heads. The weights caused the mirrors to flex too much in the rubber mounts so on the 850 the mirror stems are hollow to reduce the mass and minimize the flex. The end results are mirrors which don't

vibrate but do bounce in the rubber mounts. Compared to the mirrors on the Honda CB750K tested in January, the Suzuki mirrors could be improved but thev're a close second to the Honda and an improvement over the first efforts.

Behind the wide, long gas tank is a seat nearly as wide. Suzuki has tried several approaches to improving its seats, beginning with the GS750. When the 750 was introduced to the press, the first test bikes all sported different seats. During the introduction the test riders were asked which seats were most comfortable and the final GS750 seat was the one picked bv the test riders. Other seat configurations were tried for the GS1000. the end result being an expensive and very comfortable laminated seat of two different density foams. During development of the 850. various other seat designs were tried. The final result is a wide slightly stepped seat made with two densities of foam, firm around the edges and softer in the middle. Our touring rider's official back seat tester claimed the seat was the most comfortable motorcycle seat made. The shape, being mostly flat, allows riders to move about and it doesn't force riders into unnatural positions.

Underneath the seat, in the tool kit. are the rear tire changing tools. No. not tools like tire irons or patch kit or air pump. Tools like the front fork compressor and the centerstand lock and the swing arm holder. Reasoning that touring riders have occasion to change rear tires and that the task is difficult because it's difficult to remove the rear wheel. Suzuki engineers have supplied tools just for removing the rear wheel.

f irst the bike gets propped on the centerstand (reasonably easy to do). Then one of the screwdriver bits is inserted through two holes which then prevent the centerstand from folding up. Another screwdriver bit aligns two holes which hold up the swing arm after the upper shock bolts have been removed so that the axle can be pulled past the upswept ^ ) mufflers. To provide clearance for the w heel to slide past the rear fender, there’s a cable

• with a loop at one end * and two hooks on the other. This is used, with a lever device, to compress the front forks. One end of the cable hooks to the bottom triple clamp and the other hooks to the lower fork tube, then the lever pinches the cable together and pulls the ends closer, squeezing the forks together. It's a complex procedure to go through just to pull the rear w heel, but the job is more easily done than it would be without the tools.

Besides the tire ^ changing tools. ^ jl|\ there are .<'•* the usual assortment of pot-metal wrenches, polished on the GS850. plus an air gauge for measuring pressure in the front forks or perhaps even the tires. It's not an expensive gauge, but it's worth having.

New for 1979 on all the Suzuki GS models are folding footpegs. During tests on earlier GS models Suzuki explained that non-folding pegs were used as a safety measure to protect the rider. The nonfolding pegs couldn't be considered a serious ground clearance problem there are plenty of motorcycles which have less cornering clearance but the folding pegs w ill benefit serious pavement scratchers. On the heavyweight 850 the folding pegs may not be of as much value as the dual horns. While the noise makers couldn't be described as deafening, they’re out of the party-toy class found on most motorcycles and may even surprise a few sleeping motorists.

The most important requirements for a touring bike, comfort and load carrying capacity, have been taken care of. Superbly.

Comfort comes from the plush suspension and the supple seat. The front forks, which were as close to perfect as they could be on the GS 1000. work even better on the> 850. Here, the air boost is needed. With a base pressure of l l psi. the air forks absorb the tiniest freeway ripple. The standard pressure is 3 psi higher than the 1000's standard pressure, due to the greater weight. During the test we added a lightweight fairing. With the fork pressure raised 2 psi the effect was negligible. If a large frame mount fairing and huge tankbag were installed, more air pressure can be added. Perfect.

In back the adjustable damping shocks are. again, more valuable on the touring bike than they are on the sports bike. With a solo rider and no load the shocks work fine with the lightest damping and preload. Compression damping is so light as to not interfere w ith the absorption of tiny bumps, however rebound damping is strong enough to control the weight. Even with the stock settings a passenger added doesn't interfere with suspension control excessively. When saddlebags, top box. passenger and load are added, the shocks come into their own. Put the damping at the highest of four positions and the springs at the highest of five pre-loads and the comfort and control are still there.

Besides the able suspension, load carrying capacity is assisted by the 17-in. rear tire and strong frame. Compared to other large displacement motorcycles, the frame on the GS extends further past the top shock mounts, providing a better mounting system for accessories. Gross vehicle weight rating on the 850 is 1003 lb.; that breaks down to 375 lb. maximum for the front and 628 for the rear. Apparently the rear tire is the limiting factor on the rear wheel GVWR as the maximum load capacite of the Dunlop 4.50-17 Gold Seal also is 675 lb. A stronger K9l Dunlop would give the bike all the load capacity needed for a long-distance touring mount.

Because the GS850 has the frame and suspension components of the GS1000. it should be a good handling motorcycle. It, is. But the 850 is no match for either its larger or smaller mate in terms of ultimate cornering power. The 5 l lb. weight penalty is too much of a burden to allow the 850 to corner with the 1000. The 850 is still a stable and secure feeling bike but it can't be flicked from side to side in the same manner as the lighter bikes can. It takes more effort to steer the 850 than it does the other GS Suzukis. Still, there are no problems in the 850's handling. It goes where it’s pointed. There is no wobble or noticeable flaw; just the need for more effort than is required on the 750 or 1000. Cornering clearance also is more limited than it is on the other GS models, with the sidestand scraping during spirited lefthanders, particularly when the suspension is worked by bumps.

For touring use or even sports touring, cornering ability is adequate. Compared to any of the other Japanese large displacement touring shaft drives, the GS850 is a superior handling motorcycle. It doesn’t have the cumbersome feeling of the heavier Yamaha Eleven or the ground clearance problems of the low Gold W ing. Its suspension alone outclasses any of the other big Japanese bikes.

Certainly it doesn’t lack braking ability what with its triple discs. W;hile the discs^ appear to be the same as those on the GS1000E. the outside diameter is an inch less than that of the disc on the base GS1000. Pad material, however, is the same on the 850 as on the other Suzukis.

Unlike the manufacturers who have been changing puck compounds to improve wet weather braking ability. Suzuki tells us the pad material hasn't been changed on the new models. The result is excellent braking power, fine control and short stopping distances. Not having any rain during the test, we can’t report on wet weather braking ability of the GS850.

One characteristic which helps the big Suzuki outcorner any of the other big Japanese shaft drives is the absence of rear end deflection during acceleration or braking. On every other shaft drive bike tested so far. the rear end has lifted noticeably during acceleration and dropped during deceleration. W'hile the lifting is merely an oddity, the drop can reduce ride height and cornering clearance when power is reduced during cornering. Suzuki engineers said the 850 was designed to eliminate the problem but couldn’t say how it was done.

U.S. Suzuki testers said the engineers weren’t able to explain to them what was changed. They only knew there was a difference.

Adding the transmission shock absorber to the drivetrain has cut the driveline slack noticeably. The difference between the Suzuki and other Japanese shaft drives is particularly noticeable in lower gears.

Whether caused by reduced drivetrain slack or clutch misadjustment, the test Suzuki didn’t shift easily, particularly when cold. Starting out in the morning the motorcycle could be shifted into first with a loud clunk but couldn't be shifted out of first gear using normal techniques.

Before the 850 could be shifted out of gear the choke had to be pushed in enough to slow the engine. Because of the poor cold running characteristics of the engine, it wasn't easy to slow down the cold engine and keep the engine running.

Even warm, the transmission wasn't as easy shifting as any of the other bikes in the CYCLE WORLD garage. It always responded better to clutchless shifting or partial clutchless techniques such as preloading the shift lever and just touching the clutch to complete the shift. U.S. Suzuki testers felt the problem was caused by improper clutch adjustment and wasn't typical.

Once warmed up the Suzuki was subject to slight clutch slippage under full throttle acceleration, even when the clutch was adjusted for adequate play. During the day at the dragstrip the clutch began slipping during the top speed run. after a half dozen quarter-mile acceleration runs. While such use isn’t normal fare for touring bikes, many touring riders carry huge loads on their bikes and a growing number are pulling trailers which can be enormously demanding on clutches. Racing tuners have discovered that the Suzuki 750 clutch, w hich the 850 is based on, is weak for racing use. The 1000’s clutch is far better. In the 850 the clutch should be adequate for normal use.

Certainly the engine lends itself to gentle clutch use. By using the 1000 cams and generally mild tuning there’s enough low end power that the 850 can be started from stop with the engine at idle. It’s possible to shift the 850 into fifth gear at 10 mph and accelerate steadily, without problem, to normal speeds. Such use isn’t recommended. but it demonstrates the mild state of tune of the GS850 motor.

Despite the gentle tuning the 850 has a strong motor. Turning 12.70 sec. in the quarter mile is respectable for any touring bike. The time, compared to the Í2.78 sec. of the GS750 indicates that the 850 has more power than the lighter 750. Considerably more.

With the broad powerband of the 850. the bike could have used w ider gear spacing. The ratios are virtually identical to those in the GS750. which has a much cammier engine. Certainly the close ratio gearbox helps acceleration figures but it also means a busier engine at highway cruising speeds. At 60 mph the engine is turning an indicated 4500 rpm. The only other 850cc motorcycle made, the Moto Guzzi, runs 1000 rpm lower at the same road speed.

Although the smooth Suzuki motor isn’t uncomfortable turning high rpm on the highway, it isn't as relaxed or as economical as it could be. Turning in 41.9 mpg in the CYCLE WORLD mileage loop is a good average figure, but nothing special. The figure is almost identical to that of the GS 1000 and it’s comparable to the mileage from the Gold Wing and Yamaha’s Eleven.

Add to that the 5.8 gal. gas tank and the 850 has a respectable touring range of well over 200 miles.

Suzuki’s first shaft drive motorcycle is an attractive package. It excels in rider and passenger comfort, a quality important to the true touring rider.

Despite having a displacement disadvantage in comparison to the largest touring bikes, the 850 has performance on a par with the thousands while offering superior handling. When it comes to special features, the 850 offers many conveniences, the most important of which is the adjustable suspension. Add to that the instant availability of touring accessories to fit the GS and the 850 looks like a nearperfect touring bike.

SUZUKI

GS850

$2999