Suzuki AD 50

SUZUKI 500 FANS – T500 and GT500

The road machines – the T500 and the GT500



The Suzuki Titan was a shot in the arm for lovers of fast and loud motorcycles who could overcome the blanket dislike of two-strokes that was common at the time. As discussed in the article on the Suzuki Cobra (see Australian Classic Motorcycling Issue No. 20), the predecessor to the Titan, this was one 500cc twin which had solved the un-reliability, peakiness and generally messy nature of two-stroke riding.

The Suzuki 500 was a relatively smooth, ultra-reliable, economical, light machine which provided an impressive high speed, good acceleration and stable handling at a very reasonable purchase cost.

The off-set to all of this was noticeable vibration through the pillion pegs at over 60 mph (nothing compared to a certain 650cc British twin, though), a cloud of blue smoke from the ample exhausts when cold, significant piston/ring rattle at low revs (sometimes sounds like a can of nuts and bolts has been dropped in the inlet port) and of course a nauseating bop, bop, burble, pop, bop, bop, burble, pop from the pipes at low speed which could never replace the sound of a Norton Commando or a Triumph Trident on song.

Of course this was all irrelevant to the average young motorcyclist of the time who was being asked to choose between aging (even then) British twins, Honda 450’s and Yamaha and Kawasaki 350’s. The Titan was a full 500cc, a most popular size at the time, when 650cc was considered big. Many young riders entering the rapidly growing bike market did not have pre-conceptions of what a bike should be.

They were looking for fast and flashy bikes and performance was the name of the game. The big two- strokes were delivering the performance and beginning to dominate the Grand Prix, though that was really of little interest here before the age of live television coverage or video.

Helping to sell machines like the Suzuki 500 was their superior performance over comparable machines and their ultra-reliability and low maintenance. Hard as it is to admit now, the British competition was its own worst enemy, as perusal of contemporary journals will reveal. Quality control was at an all time low, model changes were often made for the worst, cost cutting led to dreadful bastardised machines and reliability on the road was truly dismal.

Simple things such as constantly breaking cables, vibration, and more serious mysterious seizures, short-lived bearings and burnt valves all helped to persuade the young buyer to go Japanese. No wonder rattly two-strokes became machines of some standing and attracted a loyal following that is still strong today.

A little disclaimer at this point perhaps. British bikes were, and are, capable of giving good service when ridden and maintained in the manner their designers intended. There were also serious faults with the British industry in the 60’s and while the performance of British bikes slowly improved it was often at the expense of reliability and smoothness.

But British bikes have a charisma and an appeal that is at the heart of the Classic motorcycling movement and that is why enthusiasts collect bikes as varied in performance and value as Vincents, Panthers, James and Bantams. No matter what make it is or how bad it performed at the time an old bike has a nostalgic value to someone that can never have a price put on it. This no doubt will even be the lot of early Japanese machines as the late 60’s/early 70’s rider grows older and nostalgic for the good old days that they experienced!

The Titan at it’s flashiest – the T500J of 1972

Anyway, the last time we were talking about the Suzuki 500 twin we discussed the questionable advertising hyperbole that accompanied the release of the Cobra i.e. the bike that couldn’t be built etc. Well by the time the Titan was released in 1970, this was clearly arrant nonsense and the factory was proclaiming the machine’s seemingly effortless power instead. The bite of the Cobra was exchanged for the strength of a Titan.

Understandable, for by now Kawasaki had released the 500 Kawasaki which had eclipsed nearly every bike for sheer power, acceleration and speed, albeit at the expense of handling and reliability! Thus the Suzuki advertisements of the time highlighted the steroidal, masculine features of the Titan instead.

Is the on-looker tougher than the bike – the long and lean T500J model of 1972

THE BRUTE WITHOUT BULK, the pamphlet leads, this is the giant of the motorcycle clan – yet it looks clean as a whistle with the grace of a gazelle. Does this make the point? Well, demand has caused this to be the first mass-produced 2-stroke, twin-carburetor 500cc model in the world. A cool 6,500rpm puts the full 47hp at your command with a top speed of 192kph.

When you want to stop, a dual safety system of oversized brakes and super-grip high speed tires quiets down the brute right now. smoothly. The non-glare, speedometer and tachometer is a vote for safety. Big features and small – such as Suzuki’s famous Posi- Force Lubrication and the newly-designed fuel tank luggage rack – all set out in a yummy Candy Colors with red-lined tires make this the fair- haired brute you’ve been looking for.

The fair haired brute you’ve been looking for! Somehow I think the Suzuki ad-men got that bit of market research all screwed up. They also had a nice turn of phrase when they described the auto lubrication system.

Posi-Force lubrication is the world’s most advanced lubing system. it spews pure oil, never polluted by fuel gas, directly over the. big end etc! A touch of class?

A 1972 T500J model with wrong mudguards and tail-lights, but hey who’s being picky?

For those who didn’t read the article on the Cobra, I’ll just recap a bit. The Cobra, being the bike that couldn’t be built, was a sensation in 1968. A big two-stroke that ran faultlessly, didn’t foul plugs, performed like a 650 four stroke; but was light and cheap to buy.

It had strange handling, the thirst of a cane-cutter and by today’s standards woeful brakes. It looked kinda dumpy too, in typical 60’s Japanese style, with a velour seat, a short wheelbase and a watermelon shaped petrol tank. To many of the buying public though it was a hit, everything worked together fine.

The engine and gearbox are well balanced for the road, the engine comes on strong over four thousand revs, (up to a claimed 47 bhp at 6,500), and there is no need to constantly screw open the throttle around town as there is ample low down pulling power. Not what the un-initiated would expect from a two- stroke!

So what changes had been made to the Cobra to convert it into the more appealing Titan. Well some obvious changes were made to the appearance. The petrol tank was now a more pleasing shape, reminiscent of a familiar British design, as was the more conventional seat.

Additionally, the front mudguard was much lighter and less valanced, the sidecover and oil tank were redesigned, the rear shocks were no longer shrouded and had exposed springs, American style cow-horn bars were introduced, new instruments and a passenger grab rail. Whilst the Cobra had the headlight cowl, instruments and rear shocks all colour co-ordinated, the Titan was very shiny with abundant chrome wherever possible.

The Titan was designed to bring the Suzuki 500 into the 70’s, its styling was much flashier, leaner and more colourful. The Cobra had more in common with Suzuki’s earlier mid 60’s styling efforts with its bulbous, tall tank, complete with chrome side panels and knee rubbers, large sidecovers and studded seat.

Enginewise, the Titan was little changed externally; but gone for good were the Cobra’s 10 finned barrels to be replaced by 11 finned barrels with altered porting and new stronger pistons with larger piston porting. Quieter running was possibly one benefit of the new pistons as the piston to cylinder liner tolerance was much closer in the new motors.

One outcome of the new pistons was a spate of piston skirt failures when the standard pistons were used in a sporting mode, i.e. over-revving the motor for extended periods. This was easily solved by using the heavier, stronger GT 750 pistons whose engines had precisely the same bore and stroke dimensions as the 500.

The only other significant change to the motor was the dropping of the 34mm carburettors for 32mm Mikunis. There is no evident loss of power as a result and the intake howl is much the same; but, fuel consumption dropped markedly from 35mpg on the Cobra to around 50mpg on the Titan. Cruising at 65mph in the country it was possible to return 63mpg, which is not to bad on a loaded two stroke now is it?

Whilst the changes between the Cobra and the Titan were quite marked there was little change to the character and performance of the machine. Feel and handling had been improved by the use of a longer swingarm much earlier and the test riders of the time while unable to get overly excited about the handling commented favourably on the bikes open road stability.

This stability was enhanced by the standard fitting of a friction steering damper.

A beautiful bike in its day the T500R of 1971..

Model changes were pretty limited for the Titan for a number of years. Changes were basically limited to paintjobs and minor ancillaries for four years. The T500-II of 1969/70 came in Candy Gold with a Suzuki S badge on the tank, the T500-III of late 1970 was similar except for the tank luggage rack fitted as standard. 1971 saw the T500R arrive in memorable Candy Lavender (purple to you and me) and White and with a new metal Suzuki tank badge which would remain standard fitment until 1975.

In 1972 the T500J was gaudier than ever with large chrome plastic sidecover ornaments. This model was probably the most attractive of all with Candy Vedoro Green or Pearl Orange petrol tanks. A noticeable change for this year was the adoption of a larger tail-light lens which would remain standard on the GT range as well.

1973 and 1974 saw the death knell for T500’s as we know them. Presumably in a bid to make their GT range of triples more attractive the Suzuki factory de-tuned the T500. Significantly they also modified the lower crankcase half of the motor to resolve a long-standing design weakness. The new models T500L M were designed to accommodate 1400cc of gearbox oil, some 200cc more than the earlier models.

This modification ensured that high speed running would not lead to oil starvation of the 5th, 4th and 3rd speed gear clusters. The bane of T500’s until now, the inadequate gearbox oil supply could, over time, lead to pitting of the gears and their eventual destruction as the case hardening deteriorated. It is easy to tell if the gearbox on an early model is on the way out, when riding the bike the gearbox will make as much noise as a steam driven freight train pulling up hill.

Perusal of any T500 enthusiast’s garage will unearth a comprehensive supply of stuffed 4th and 5th gear clusters!

The cynical marketing exercise of de-tuning the Suzuki T500 to make the GT range more attractive did not work. The GT380 and 550 triples were overweight, peaky and unattractive. The T500 had a loyal following and still sold steadily if unremarkably.

The subtle changes to the inlet port and the carburettors had robbed the T500 of approx. 3hp and returned the fuel economy to near Cobra standards. The Suzuki factory has a lot to answer for!

The following chart illustrates the factory marketing ploy;


1972 T500J 400lbs 47 @ 7000rpm 5.3 kg/m @ 6000rpm $895

1973 GT380 392lbs 38 @ 7500rpm 3.9 kg/m @ 6000rpm $939

1973 GT550 412lbs 50 @ 6500rpm 6.1 kg/m @ 6000rpm $1215

1973 T500K 400lbs 44 @ 6000rpm 5.4 kg/m @ 5500rpm $925

Other than the gearbox, there was no real change for the better in 1973 through to 76. In 1976 we saw the Suzuki factory finally make some significant changes for the better, well overdue and as usual with Suzuki, some bad always accompanies the good.

The year 1976 saw the unveiling of the GT500, same motor, same strangled power; but, the brakes were finally sufficient to cope with the bike’s weight and power. Despite statements to the contrary by enraptured road testers the Suzuki T500’s twin leading shoe drum brake had always been woefully inadequate. The GT500 wore a single front hydraulic disk brake, identical to that which had been fitted to the GT380 and Gt550 since 1973!

The forks were similar as well having 35mm stanchions and identical triple clamps to the GT range. The instruments were also identical to those found on the GT range.

The 1975 GT500 engine was a significant advance

A non-GT item of inestimable value was the fitment of the Pointless Electronic Ignition (terrible name that!) or PEI system which disposed of the twin points/alternator used on the T500. The PEI system consisted of a rotor, CDI unit and single coil which fired on every stroke (i.e it has a wasted spark). A simpler system, which does not need adjustment and provides a more powerful spark and yet Suzuki had been using this system on their 250 trailbikes since 1970!

Why the wait, Suzuki?

The last of the line in 1976, the GT500

Another example of parts rationalisation was the use of the GT750 fuel tank on the GT500. A cheap plastic insert replaces the unnecessary radiator access flap on the front of the tank. The tank gave welcome extra range to the 500; but didn’t really suit the machines lines. A new seat accompanied the change of tank.

Thus modified the Suzuki 500 twin saw out its days and in 1977 the GT500B was the end of the line and hardly any of this model were ever delivered by the factory. The last few GT500s on the showroom floor were heavily discounted and moved away to make way for the new four cylinder four stroke range. The King was dead!

Significantly the GT triple range, which had stifled development on the Titan, died with it. There was not much sorrow ar the demise of the triples; but the 500 had earned a loyal following.

T500 fans had watched frustrated while watercooled versions of the motor had produced formidable power on the track and gained triple disk brakes and suitably sporty styling. None of this development was realised on the road, however. The Suzuki factory was distracted by its RE5 Rotary engined fiasco and blinded by its range of triples.

What would a lightened, better framed, watercooled twin with triple disks in 1973 have performed like? The race bike was able to give 85bhp by 1975. If Suzuki had put a cheap, lightweight, sporting replica on the road in 1973 it would have become a Classic and beaten the RZ500 Yamaha and the RG500 Suzuki race replicas by 10 years.

If only?

Copyright reserved: M Barnard 1989

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