Sunday 29 January 2017

Triumph Trident


The Trident actually beat the Honda CB750 to the marketplace back in 1968. This was a time when Triumph were famous for building light, fast, vibratory and weird handling big twins. The Trident was in a similar vein except that it was then a heavy, fast, vibratory and weird handling triple.

Using many engine components that stretched all the way back to the original vertical twin design of 1937, that the Trident engine actually made it from the drawing board to the production line was, in itself, a great shock and surprise to anyone who knows anything about engineering design.

Thus, the most surprising thing about the Trident is that it can be such good fun out on the road. The result one guesses of the engineering input of some of the long suffering engineers who had to work miracles with limited funds and out of date machinery. This is, of course, no excuse for the poor characteristics that the Trident shows in the harsh light of ownership.

The OHV engine has marginally long stroke dimensions of 67 x 70mm, develops 58hp and ls basically a Triumph twin with an extra piston and cylinder thrown on. Although many engine components are similar to the twin most of them are not interchangeable, which in the end rather made the whole scam a bit pointless. Much better to have started with a clean sheet of paper.

The first model had drum brakes similar in design to the twins, these were changed for conical hubs in '71, but it wasn't until '73 that a single disc was able to cope with the 470lb of steel and alloy. The '71 bike tested was fitted with the later disc and earlier weird if unique silencers.

It was not until 1975 and the introduction of the better T160 that the Trident gained the luxury of an electric starter. This particular example delighted in refusing to start on occasions. Even threatening the thing with a large hammer had no effect.

Whether this was a result of wiring defects or the poor quality of the contact breaker assembly I could not say. But poor starting is a well known problem among Trident owners. When the bike was in a good mood, it would explode into a meaty growl after three of four fairly desperate kicks.

Two problems immediately arise in trying to engage first gear. The clutch lever requires the use of molegrips to actually get the lever back to the handlebars and the clutch plates suffer from drag when the oil is cold. Like a 1910 Triumph twin, the Trident has to be kicked over with ignition switched off and clutch pulled in, to free the plates. The degree of drag is much greater than on, say, old Honda twins when first can be engaged, with the front brake on to stop the bike leaping forward. Try that on the Trident and the engine stalls with a deal of nasty noises.

The three Amal carbs need very regular balancing (100 to 500 miles) to achieve a regular tick-over. The low level of power development really doesn't justify the presence of so many carbs.

Blipping the throttle doesn't send the rev counter needle immediately flicking into the red, but the noise from the exhaust is quite exciting; triples and big vee twins have always made the most interesting sounds. First gear engages with an almost BMW type clunk, even with the clutch plates freed.

The bike won't take off with less than two and a half grand on the clock. The triplex primary chain and tortuous path through the gearbox means there's quite a lot of slop in the transmission. Whack open the throttle in first and the bars go a little light, the back end squats down and the vibration through the bars, footrests and petrol tank is more than a little noticeable. Not as bad as a Triumph twin but more intrusive than one of the old Honda fours.

The gearchange action isn't light but it is positive. Wear in the box makes the second to third change difficult and finding neutral at a standstill almost impossible. The primary chain would be in trouble trying to transmit half the Trident's power - it is noisy, absorbs huge amounts of power and wrecks both its tensioner and itself. Careful maintenance and regular oil changes give it a life of around ten thousand miles.

The Trident feels top heavy in town, the petrol tank is too wide, the seat height too high and the throttle and clutch too heavy. The steering geometry is set up to suit high speed handling in a similar manner to the twin, but the triple has too much weight to get away with this and retain the low speed agility that the twin was justly famous for.

The Trident needs brute force to drag it through traffic at a decent pace, but it is helped by some feedback from the road and a sensitive disc brake. Kids on even restricted 125s can make the triple look silly in built up areas.

The Trident only begins to make sense on fast A roads. Those relatively wide, sweeping bends let the bike's heritage shine through. In these conditions it can show a clean pair of exhausts pipes to Honda's CB750, although to be fair to the Japs, most of the modern 550s will make the Trident look very silly.

There's a nice surge of power around five grand, the bike will accelerate up to the ton in top gear with relative ease, higher speeds are a product of excessive vibes, an uncomfortable riding stance and handling that can do some very nasty things if the power is suddenly backed off.

The single downtube frame was a sort of scaled up sixties Bonnie frame, that shared with it poor support for the swinging arm. In the early twin, this used to verge on the suicidal but was improved by adding plates between engine and frame that held the outer ends of the swinging arm spindle. A similar set up is used on the Trident, but the frame still relies on a basically weak central saddle tube for some of its rigidity, with the result that the swinging arm can thrash about at high speeds.

For a lot of the time the Trident feels commendably secure, much better than the Honda four, but combine a bumpy curve with the sudden need to change direction and the reality of the Trident's design - too much weight carried too high - suddenly makes themselves felt. The back end wriggles and sometimes the front forks join in, the handlebars flip back and forth. Nothing as bad as a Kawasaki triple, but there is a lot of mass involved here and it does need plenty of muscle to keep it under control.

Motorway cruising was no problem. Up to 85mph vibes were acceptable, between 85 and 105mph the vibration became much worst and, at times, felt as if the whole plot was going to fall apart. Riding at this kind of speed for any length of time made the engine overheat, the valve gear make enough clatter to silence the exhausts and blew every bulb on the bike. From 105 to 120mph things smoothed out again, but the bike couldn't hold this speed against headwinds or hills.

Wringing the last few mph out of the bike brought back the vibration in its most intrusive form, it felt as if every moving part in the engine was about to self destruct, the mirrors were a useless blur, the instruments were gyrating wildly and the engine sounded as if all the ball bearings had shaken loose.

Top speed varies from model to model and ranges from 120 to 130mph, this particular bike with forty grand and two rebuilds, was unhappy going past a true 120mph. Above 100mph the bike goes into a gentle weave even on flat, smooth roads. This weave gets worst as speed increases but it never switches into a speed wobble even on bald tyres. Although riding on bald tyres in the wet is not a good idea as the weight of the bike doesn't make it easy to pull the Trident out of a slide.

Riding in the wet would have been quite pleasant as the bike has a secure feel and a reasonable disc, but the engine likes to try to run on two or even one cylinder. If the engine cuts out in a corner in the wet the sudden loss of power can have the back wheel swinging off line. Some Trident owners are of the opinion that this is just good clean fun...

The disc brake was in trouble knocking off speed from 100mph plus speeds, but was otherwise as good as any Jap disc of the period and much safer than earlier drums fitted to the Trident. Disc pads last for about 7500 miles and are quite easy to replace.

Fuel economy is not good. Even the most moderate use does no better than 50mpg. At 80mph it averages 42mpg, at 100mph it's down to 35mpg and really flat out a frightening 28mpg. Fuel averages out between 38 and 45mpg. The four gallon tank gives a range of about 150 miles before reserve. Chain wear isn't too good, either. Between five and eight grand depending on use and maintenance.

The engine has a number of problems arising from the basic design and others from a lack of regular maintenance. The exhaust valves like to burn out due to overheating, especially those of the centre cylinder.

Maintenance every 500 miles helps but the only real solution is to ride slowly. The primary chain has already been mentioned. The clutch likes to burn out, but it's quite cheap to repair. Some engines seize up without warning, oil changes every two grand help together with regular filter changes. The contact breakers fall apart and the advance/retard unit sticks, making starting impossible.

There are other minor problems with pushrods, tappets, camshafts and  gearboxes. The Trident needs lots of attention to stop it giving trouble, but spares are plentiful and cheap when compared with Jap stuff.

The BSA version, the Rocket 3, had a similar engine with the cylinders canted forward and its own stronger frame that wasn't so keen on shaking its back end. The Rocket 3 was finished off in '72 and its relative rarity has gained it cult status and higher prices.

The BSA engine reappeared in the T160 with an electric start thrown on for good measure. The new Trident had an engine with some of the problems sorted out (going as far as was possible without redesigning the engine) and an uprated chassis. Although the new bike weighed even more than the T150 (510lbs) it handled better and really was the bike Triumph should have introduced in '68. In the mid-seventies the demise of the UK industry had gone so far there was little hope for the bike. The T160 is even more expensive than the old bike but a much more usable machine.

Engine life of the T150 varies enormously, depending on maintenance and riding technique. Really thrashed and neglected engines will need a major rebuild by ten grand, at the very least including a complete top end overhaul, a rebore & primary chain. The highest mileage that I could find in which the motor has not been taken apart was 35000 miles. There are a few bikes that have done over a hundred grand, but these have had most of the internals replaced since leaving the factory, at least once if not two or three times.

The Trident engine is not easy to work on, and requires a great deal of attention to detail in reassembly to avoid another early rebuild. Norman Hyde is the leading supplier of spare parts, tuning goodies and big bore kits. This stuff has a pretty good reputation and filling up the engine with all the appropriate bits and pieces makes it much stronger and longer lived.

Prices vary between £750 and £1500, although some people try to demand as much as three grand for so called immaculate examples. Finding a bike for £750 will be hard going but not impossible.

Noisy top-ends and primary chains are the most obvious symptoms of an ill engine. An engine on the way out will also make lots of vibes at all revs and have smoke coming out of the silencers. It's quite hard to disguise the effects of abuse, unlike the twin which will just keep going to the last, expensive moment. It should be possible to buy, something that's running well for around a grand, although it'll probably have a few non-standard parts fitted.

Having ridden this Trident and a few other examples, I can appreciate why some people like them so much - on the right roads the bike really shifts for a heavyweight multi. The fact that the Japs have redefined the multi market with lighter an more powerful bikes rather leaves the Trident gasping for beath.

The bike never had much to offer the economy-minded rider and now doesn't have the performance to cut it amongst the new breed  of 550s (or even 400s). It doesn't offer much more performance than the twins, and isn't that cheap to run.

Johnny Malone