1975 Honda GL1000 Gold Wing

It’s big, bulbous and ostentatious, but Honda’s innovative GL1000 is a technical tour-de-force and the most significant new model in motorcycling in a decade! Brian Cowan has the full story.

Rumours about a big, new Honda have been around so long that the bike was almost part of motorcycling legend even before it was introduced.

Through all the expert and not so expert guessing Honda remained inscrutable, denying nothing, confirming nothing, saying nothing.

Now the bike is reality the company’s lack of activity for the past few years makes sense. Most of the development work would have been put into perfecting the big fella, making sure it was a landmark in the same manner as the 750 was. Once again, the Japanese giant has pulled off the scene-stealer beyond compare, produced the marvellous mechanical rabbit from the corporate hat, and dared the rest to match the trick.

And what a trick: The GL1000 is not just another motorcycle, slightly bigger, slightly flashier, slightly more complicated than before. Sure, it’s those things separately, but the total effect is of a new type of machine, a supertourer if you will.

It’s not only the capacity, although the magic litre has always exerted a fascination for motorcyclists, acting as the barrier at which a bike is a “real biggie”. Hence the aura surrounding the Vincent Shadow, the Ariel Square Four, the Harley-Davidson V-twins.

But to look at it from a strictly practical point of view there ain’t much between 850 or 900 and 1000. So why don’t Norton or Kawasaki pull the same stunt? Possibly because they have motors which are still reasonably compact. The Norton twin started life as a 500 and hasn’t got much bigger in the motor department over the years. The Kawasaki has a similar ­sized donk to the Honda Four or any other 750, most of which can be bored out to a full litre without much trouble.

They all still look like a 750 which is one thing the GL doesn’t. From go to whoa it exudes the impression of largeness. Everything, but everything about the bike is massive, solid, substantial. The unkind could call it a car minus a couple of wheels, and in some respects they’d be right. Yet calling the bike that would be no reflection upon it. Many good ideas have been picked up from the world of four wheelers and used in the model’s design.

Underneath it all the GL1000 remains very much a motorcycle and a very good one at that. It is silent, smooth and powerful, for its size and weight suspension behaviour is remarkable, while handling is better than many a smaller machine.

The motor is the most remarkable part of this remarkable bike, and in no small measure is the reason for its size and weight.

Looking as if it had been plucked straight from a car, the unit still owes more to motorcycle design. It’s just that the way it’s aligned is different.

Between the vertically split alloy cases sits a one-piece crank, supported on three plain bearings attached to the right sidecase. A pair of crankpins, set at 180 degrees to each other, sit between each bearing journal. In effect, the motor is two 180 degree parallel twins set one beside the other, the right-hand pistons being set staggered forward from the left.

Or looking at it another way, it’s two BMWs one behind the other, with one set at Top Dead Centre while the other is at the bottom of the stroke. In usual Honda practice the bike uses two ignition circuits, each plug firing every time the piston comes to the top of the stroke, the spark on the end of the exhaust stroke having no effect.

A points cam on the end of the left side overhead cam shaft triggers two sets of points, one for the front cylinders and one for the rear. Since the shaft turns at half engine speed the points cam has two lobes, tripping each breaker once each revolution.

The rest of the working section of the motor follows normal Honda Four and car practice, with bolted up plain big end bearings and similar at the small end. The gudgeon pins are pressed into the pistons and don’t use retaining circlips as is common with bikes.

Three-ring pistons squeeze the charge into hemispherical combustion chambers with the valves set skewed to aid turbulence and promote more efficient burning. The little NGK D8ES plugs are set at a shallow angle into the combustion chambers. From the outside they are easily accessible, pointing upward on the top of the barrels.

Single overhead cams with valve rockers and screw-type tappet adjusters are normal fare for the Honda range and the GL1000 is no exception. The camshafts are located by three plain bearings, clamped by a one-piece cast alloy bridge which also carries the four short rocker shafts.

The novelty comes from the method of camshaft drive which is by toothed rubber belts as has been used recently in some cars. The belts sit behind distinctive housings bolted to the front of the motor and drive wheels splined to the end of each camshaft. Whereas a chain of equivalent length would require sophisticated tensioning devices the belts require only an idler wheel each. Other benefits are smooth and silent running, although if experience with cars is any guide they are likely to be as expensive as a chain and in need of more frequent replacement.

Honda has stuck with a Hyvo multiplate chain (as used in the other Fours) for the big fellow’s primary drive. The clutch shaft (mainshaft) lies underneath the crank on the centre of the crankcase joint, with the clutch projecting to the rear of the motor. No ten-minute stripdowns here – for any major work on the unit the motor would have to be removed from the frame, itself a daunting task.

To the right is the gearbox output shaft, from which a spur gear transfers effort to the main driveshaft. The drive is placed above the transmission, about on a level with the crank and off to the right. Like the BMW, it is encased by the right side swingarm and incorporates a universal joint at the line of the pivot.

Farther back, sliding splines are used to counteract minor changes in length as the suspension moves, while the hypoid rear axle set is contained in a beautifully cast hub.

Interestingly, the Honda engineers have gone for a very old mechanism in providing drivetrain shock absorption. This is matched rounded dogs backed by a strong coil spring, set into the main output shaft just before it projects through the rear of the motor casing.

Anyone who knows the old (pre-1950) British singles will realise the unit is almost a direct copy of what the bangers used to have on the crank behind the primary chain sprocket. Knowing Honda, the engineering group would have tried every type of drive line shock absorber known to man, plus a few brand newies. It’s good to know there’s really nothing new under the rising sun.

Various other shafts and gear trains live inside the huge volume enclosed by the Honda’s engine cases. A chain from the back of the clutch actuates a shaft running fore and aft in the lower left section. This carries the water pump (at the front) and two trochoid oil pumps, the larger scavenging the wet sump lubrication system, and the smaller taking oil from the clutch housing.

A mesh filter on the intake side in the sump takes care of particles of scunge while a disposable paper full flow filter lives behind a cover on the right side of the motor.

The bike has a neat stroke of genius aimed at eradicating the sideways torque reaction of shaft drive bikes with fore-aft cranks when the throttle is blipped. Instead of the alternator being placed at the logical place at the front of the crank, it’s gear-driven to the side.

Why? Because on the crank it adds a considerable weight to that already whizzing around, the result being an even worse. torque reaction. Geared to the crank, it spins the other way. Like the counterbalance shafts used by Yamaha and Kawasaki, its inertia acts against the crank, the result being no torque reaction. For all practical purposes anyway. If you sit and blip the throttle at a stop, you can feel the merest tendency for the bike to rock to the right, about as much as you’d get from a puff of wind.

The alternator is a heavy-duty 300W monster, built to take on the demands of electric-only starting and a complete electrical system. There is a kick lever, for emergency only, carried clipped to the side of the “petrol tank” and fitted to a tube and ratchet mechanism at the rear of the motor. Use is the same way as a BMW starter – kicking down while facing the bike on the left.

The electric starter is nestled low on the left of the motor, above which is the gear-driven generator. All in all the engine of the GL1000 contains an impressive number of things which go round and round, be they chain or gear driven.

Were it air cooled, it could well be a terribly noisy devil, but the handsome water jacketing keeps the din well down. A big radiator mounted to the front downtubes circulates a 50/50 mixture of antifreeze and water in a pressurised system. Behind it an automatic electric fan switches on when the temperature reaches 100 degrees C. The rider can keep an eye on how things are going from the little temperature gauge set into the bottom of the tacho. A separate plastic header tank located high on the frame allows a quick check of the level and the chance for topping up even when the system is warm and under pressure.

Another of the bike’s remarkable features is its exhaust system, for which the factory makes a claim of 77 dB. And if the figures don’t mean much, 77 is very, very quiet! So the thing should be. It’s a monstrous horseshoe-shaped unit, curving ahead of the rear wheel and projecting either side to terminate in a pair of chromed outlet pipes. Like the header pipes from the block, the main body of the muffler is finished in a neat matt black. The header pipe pair from each side siamese into one before clamping to the muffler.

Quiet it all is, but one hopes it isn’t prey to the corrosion problems experienced by the 750 Four. The replacement cost would be staggering judging by the internal complexity of the system.

Honda has stuck with the well-known Keihin CV carbs for the flat four. They offer quick response and good economy, although we found the bogey of low-speed snatchiness has not been fully put to rest. The four 32 mm units breathe from a cast alloy plenum chamber bolted to the top of the engine cases. Air is fed through a treated fibre filter set inside the “tank”.

That “tank”. It is the single most unusual feature of a bike crammed with unusual tricks. With the real petrol tank taking up all the room it can under the seat, behind the motor and in front of the rear wheel, the top one is merely a dummy, but a very useful one at that.

A lock at the rear holds down the hinged top section. Flipping it up uncovers the fuel filler cap and a plastic tray with room for minor storage and holding the tool roll. Lift this out and you can undo a pair of big screws which allow the sides to drop. Each is retained by a wire stay, the right side one gives access to the radiator header tank and the radiator cap plus the emergency start lever.

On the other side the eye is amazed by a staggering collection of electrical equipment. Actually, it’s not much more than the average bike, but with more room to spread around in, each unit is built bigger and looks more rugged. All are neatly laid out and well labelled, so fiddling with the wiring system on the GL1000 should be a joy.

On the other hand there’s a ton of it, the bike is crammed full of tricky ideas, most of them in some way tied up with electricity. Like the automatic cut-out on the starter circuit which stops it from firing if the bike is in gear unless the clutch is pulled in. Very handy in the case of the 1000, because if ever it fell over righting it would be like towing a beached whale back to the waves single-handed.

Then there’s the audible indicator alarm, a high-pitched beep which sounds when the flashers are in use. It’s a handy reminder to switch them off after a corner and it’s so penetrating you can’t ignore it.

The real petrol tank holds 19 litres ( 4.2 gal) which is not bad for the bike’s prime function of tourer, although since it is fairly heavy on the juice, range per tankful isn’t tremendous. A mechanical pump on the righthand camshaft pulls petrol through a filter and thence to a vacuum valve on the plenum chamber for the carbs, which in turn routes it to the various float bowls .

The carbs have quite complex linkages for the main butterfly valves plus a duplicate set for the chokes. These are actuated by a pull button set beside the speedo. The test bike proved to be a somewhat reluctant starter, and needed full choke for a cold fire-up. Then it required a five-minute warm-up period before it would pull happily without stuttering. Only when the needle of the temperature gauge was well on its way across the dial would it sound ready for the fight.

Because the exhaust is so quiet, the mechanical noise from the motor seems correspondingly loud, although it is well below the average bike since the water jacketing masks most of it. There is a gentle whistle from the rubber cam drive belts and a clatter from the tappets, plus various whines and gentle grumbles from the transmission.

The clutch on the test machine tended to take up fairly suddenly, although lever pressure wasn’t so light that the friction point couldn’t be picked precisely. Through the test it would engage with a slight grinding noise when starting off. Then right at the end as we were taking the acceleration runs, it burnt out.

We had to forgo the chance to take additional runs or check for top speed. However, the one clean run we’d accomplished was a blistering 12.6 seconds for the standing 400 metres – a remarkable effort right there in Kawasaki 900 territory!

Despite giving away something like 40 kg to the Z the GL is equally as strong a performer. The factory claims 84 hp from the flat four, a figure we can believe. It really scampered.

On the basis of the acceleration figures and the claimed peak power rpm (7500), the bike should pull that happily in top, making the upper ceiling of its performance close to 210 km/h (130 mph). Again, that is right into Kawasaki 900 territory.

The Honda’s powerband is broad, and it pulls the massive 265 kg (584 lb) dry weight around from anything above 2000 rpm. But it’s also peaky; torque gets better and better as the revs rise, coming in really strong at 5000 rpm, reaching a mind-blowing peak at 6500, and then dropping fairly swiftly. The tacho is redlined between 8500 and 9500: if usual Honda practice is being followed the segment is actually an “orange” zone, with the no-no line at the upper limit.

In the lower gears there’s so much power to spare the motor would pull happily up to these exotic figures, but in normal circumstances there’s no need to go anywhere near that far. Effort drops away past 8000 and there’s always more waiting in the next gear. We found that the best acceleration could be gained by limiting upshifts to the modest 7500 rpm peak power figure.

In other words, the company has built a bike with the toughness to rev hard, and then given it so much punch at lower speeds there’s no need to knock it around. Coupled with the water cooling, long life should be assured.

On the move the bike is exceptionally silent and exceptionally smooth. You know it has to be with the cooling, the muffler, the piston firing every 180 degrees of crank movement, but it still comes as an eye-opener. Honda has done its homework well and turned out a top-class product.

As a long-distance tourer the bike has the easy power to keep going almost indefinitely. Overtaking manoeuvres are carried out in less time than ever before while headwinds, hills and riding two-up are virtually unnoticed.

And so smoothly does the motor perform all its tasks that it’s hard to pick at any time what gear the bike is in, apart from the figures shown by the tacho. Around town for instance, it will happily pull anything from second (4000 rpm) to fifth (2000 rpm) at a 60 km/h road speed and sound little different in both cases.

As with any big, upright machine, cruising speeds are limited by wind strain on the rider’s upper body and arms. Consequently the GL becomes a pain to hang on to above 150 km/h for any length of time, despite the fact that it will achieve 175 km/h plus (110 mph) in a twinkling and maintain it indefinitely. Fitting flatter bars than those supplied as standard would be a must for the serious touring rider, while the addition of a fairing should also come under some scrutiny.

On that subject the factory advises against handlebar or fork­mounted fairings. The big four is rock-steady at high speed but the warning carries a hint that fairings tend to introduce nasty habits. This has been the experience with the Kawasaki 900 when set up for police work, and Honda is taking no chances. Above 192 km/h (120 mph) is exotic territory and you can’t fool around with steering stability.

On the other hand. a well­-designed fairing bolted to the frame should have a beneficial effect as well as improving rider comfort.

While on the question of comfort and touring (for this is the job for which the bike was designed) we were slightly disappointed with the size of the fuel tank allied with consumption. At around 13 km/litre ( 36 mpg), or a touch more at cruising speeds, the bike will stretch to 250 km for a tankful. That’s not bad, but not in the 300 km and over class of the serious touring machine. And there’s no way of increasing capacity unless you go for some exotic pannier-mounted auxiliary tank.

At the same time the need for as much fuel space as possible has caused the factory to provide a seat which is thinner and harder than it should be, meaning that the rider’s rear end starts suffering halfway through a long day. The GL is quite a comfortable bike, but simply not up in the top bracket. Seating position is good. The seat itself is low to the ground, so that normal­sized people don’t have any bother wrestling the bike’s weight to a stop. The footpegs are also set low, so there’s no feeling among the long-legged brethren of having their knees jammed under their chins.

In fact it might be too much the other way for short riders and the firm could look seriously at raising the pegs. Not only would the comfort improve slightly, but one of the machine’s biggest bugbears, lack of ground clearance, would be improved.

As it is, the pegs will have to remain where they are, for they touch only just before the muffler and centrestand, and act as an early warning system. They swivel back, and have a round metal knob at their outer end which touches first and gives the warning.

Of course jacking the springs up is a must to aid ground clearance. In the long run the factory should have a close look at the problem and redesign the muffler to sit higher and/or further in. It’s such a great lump at the moment that surely the designers could include the same baffling in a smaller volume. Then the pegs could be raised, and the mad fangers among us would be happy.

The only sort of road the bike has some trouble on is the tight, one-corner-after-another sort of stretch, with the bends posted at 35 km/h. In those conditions the jerkiness of the CV carbs becomes apparent, and the bike is either slowing down suddenly, or getting most of the 84 horses together in an equally sudden rush. There’s no way to do it as smoothly as this sort of road demands.

Despite the steadiness of the steering the effect of the weight is felt when flicking from one side to the other. No wobbles, simply a longer time than the average bike to lay over. But we must say it again – on medium speed bends and over the GL1000 handles remarkably well.

It also stops well, although here again the weight is the limiting factor. The big new calipers on the double front discs are a departure for Honda in that they are fully floating instead of pivoted. They are well-matched to the bike’s needs, give great control from an easy halt to a full-fledged anchors -out panic effort. Squeeze hard and they’ll lock the front wheel, which is more a reflection on the choice of a rib tyre than any fault in the brakes.

At the rear, another hydraulic caliper provides equally good service. This one is pivoted, on a long cast alloy arm, and offers the same degree of control as the front pair. Applied hard it will lock, but on most occasions it does the job calmly and quietly. During the test we had a lot of rain to ride through and despite our fears the brakes didn’t go all weak and useless. Somewhere along the way the boffins have done their homework, because the front brakes don’t even have water shields like Honda’s other disc brakes.

The thing to remember about the Honda GL1000 is not that it’s as quick and fast as any bike yet produced, or that it’s crammed full of enough trick ideas to give the opposition a year of sleepless nights along with enormous weight (which can be a real pain when shoving it in and out of garages).

If you’re committed to a fast line through a tight corner often you have to keep cranking over, and soon after it’s the turn of the neat black muffler to cop scratches along its underside .

Granted, the situation improved when we jacked the rear springs up to the top preload position (which, incidentally, gave the best combination of comfort and suspension control), but we could still hang up both sides (the centrestand on the left) when riding solo. With two people and a mountain of baggage aboard watch out!

Okay, so the bike has not been designed as a sports scratcher but as a long distance beater. This we admit, but at the same time argue that any bike should be able to be herded through bends pretty fast, particularly if it has better than average handling and suspension as does the GL.

Better than average? From a big Honda? Right on baby! The engineers really put their heart and soul into this one, and have come up with a bike that’s easy to manoeuvre at low speeds yet tracks steadily at high speeds. It’s not as good at super-low stuff as the Suzuki Rotary, but it’s so much better all round than the 750 Four that you wouldn’t think the same company made both bikes.

When you think about that weight for a moment the job the factory has done becomes even more impressive. Two hundred and eighty-six kilograms ready to roll! That’s nearly three times the average 125-175 trail bike! Steering has to be good to compete against figures like that.

The suspension also does a remarkable job. The forks handle the whole deal without a moment’s worry, steering a neat middle course between stiffness and wallowing. At the rear the springs have to be jacked right up, which makes the bike somewhat stiff­-legged over small bumps. The alternative is to leave the preload on position two or three, and be comfortable over the small bumps, but cop a lot of movement over the larger ones.

It’s not crook damping, it’s simply that there’s a lot of weight, and once it gets on the move even the world’s best dampers have a hard job buttoning it down. Better to reduce the initial movement with stiffer spring settings. When we did, we were impressed with the way the damping controlled movement.

More importantly, it is a good motorcycle when the classic standards of handling, braking, smoothness and silence are applied.

No matter what pricetag the GL had, it would set new standards. It’s listed at below $2500 and that makes it one of the hottest bargains of the decade. Granted, the costs will catch up in other ways. Motor overhauls will be no longer a thing to do by yourself on a spare weekend. Even pulling the engine out would require four or five hours plus the help of three strong mates and block and tackle.

Looking back, it’s generally acknowledged the 750 Four marked the dawn of a new era in road motorcycles. The company may not sell as many GLs but the introduction of the model marks an even more significant milestone.

Quite suddenly, motorcycling has taken a gigantic step forward. It’s name is the Honda Gold Wing.

By Brian Cowan, Two Wheels, July 1975

Guido from AllMoto takes a look at how the early Gold Wings stack up as a classic bike buy today here.