Yamaha XV 1000 TR1

THAT'S JOHN HUNTER'S CONCLUSION AFTER ROADTESTING JAPAN'S 1000CC V-TWIN.

WAY BACK IN THE SWIRLING MISTS OF motorcycle history, in those heady pioneer days when major manufacturers operated from a small wooden shed at the bottom of their Mam's garden and new models rattled their way on to the market a mere two weeks after Willy, Alf or George had sketched out the basic concept on the back of a penny postcard, somebody somewhere had the bright idea of converting a single pot thumper into a revolutionary V-twin.

Aye, the notion has been around since Albert Tatlock were a nipper, by gum, and beer were thruppence ha'penny a gallon. V-twin Harleys and Indians were plying the streets of Milwaukee and Massachusetts before the first war. Brough Superior's 980cc SS100 first hit the road in 1924. And Moto Guzzi started producing bikes with in-line 120° V-twin motors as long ago as 1933.

The reason for the early popularity of this engine configuration is that the conversion from single pot to V-twin was a relatively simple matter of grafting another cylinder on to the same crankcase and fitting the new motor into the same bicycle-type frame. The result was a machine with twice the capacity and a good deal better performance.

Contrary to initial impressions, however, Yamaha's new one litre entrant into the V-twin stakes, the TR-1, is not simply two SR500s spliced together but is a completely new machine designed from scratch.

There are two stories concerning the origin of the Yamaha V-twin concept. The official US version of events has it that the company's US subsidiary, Yamaha Motor Corp, identified a market need in the States for a big V-twin (what on earth gave them that idea?) and commissioned the XV750 from the design boffins back in Hammamatsu. Europe then got a sawn-off version of this factory chopper  the TR-1.

The other tale  the official UK version  is that Paul Butler's Yamaha NV in Amsterdam identified a market niche in Europe for a big V-twin tourer, pointed it out to Japan and got the TR-1. According to this story, the poor little XV750 is an emasculated version of the Euro-tourer  a sort of V-sign to the States, if you get my drift.

Whichever of these  if either  is true, it should be pointed out that there are in fact three, not two, Yamaha V-twins in production.

The TR-1 or XV1000 has a 980cc motor, was designed for Europe's high-milers and is on sale only on this side of the Atlantic.

The XV750SE was designed for America's boulevard cruisers and is on sale in Europe and in the US, where it is called the Virago. The XV920 is a smaller capacity version of the TR-1 and is on sale only in the US, where apparently it falls into a cheaper insurance category than would a machine with another 60 cubes.

Now motorcycle history — remember those swirling mists — has largely shown that if you don't change with the times you don't survive (BeeEmdoubleWho? The Triumph upright Twhat?), however, as acutely highlighted by the miserable failure of the rotary Suzuki RE-5, you need to get it right before you get involved in mass distribution.

Yamaha, unlike certain other manufacturers, don't tend to sit on their collective backside and copy Honda, and this has resulted in the past in such radical departures as the XS750 triple, the SR500 single and the watercooled 250 and 350LCs, and in the present in the new V-twins.

So what of this super-spiff TR-1, this 'big road sports model' as the publicity blurb puts it, with added 'super quiet accurate operation'? Is it a BeeEm? Is it a Harley? Or is it SuperYam? And whatever it is, have they got it right? You only have to turn the ignition on and start the engine to discover how superficial is any imagined resemblance to the big Harleys. Gone is the familiar vibro-massage, whump, whump, whump, of the big American, as if they've excised its dicky iron heart and replaced it with the muffled rattle and gentle undulations of an efficient alloy pacemaker. It's not a Japanese Harley and it doesn't try to be one. What it does attempt, I think, is to challenge the domination of the sports tourer market by the likes of the big BMWs and the CX500. Yamaha have given the basic V-twin engine design a projected useful life of ten years — into the 1990s! — and that's a long time in terms of modern motorcycle design, a time that it will attain only if it can succeed, if it can out-BeeEm BMW, if it can out-CX Honda, if it can find, or has found, that elusive ideal combination of flexibility, handling, safety, comfort, reliability and economy that makes long-distance riding a pleasure rather than a chore.

The TR-1 is built around a comparatively small and therefore lightweight pressed steel spinal frame which Yamaha designates 'monococfc' design, to distinguish it from monocoque (which it ain't), to which is bolted a sub-frame at the rear which supports, inter alia, the battery, seat and grab-rail. The engine is a stressed frame member, replacing the entire lower part of conventional frames.

Each highly oversquare pot breathes through a single inlet valve operated by a single overhead cam, and the mixture is sucked through two 40mm Hitachi CV carbs with SU-type butterfly valves, which nestle in the 75° angle between the pots. Air is ducted to the carbs through the interior of the spine frame from an air cleaner beneath the seat.

Exhaust gases are chuntered out of the pots, again through a single valve per cylinder, into at the front a thick header pipe double-skinned to prevent heat discolouration and at the rear a narrower single-skinned pipe more or less concealed behind the side panels, and thence into the open air via long conical mufflers.

Power is transmitted from the crankshaft via a spiral geared primary drive and a conventional wet multiplate clutch to a 5-speed gearbox whose constant mesh is sweet enough to make clutchless changes — at least in the upward direction — all but effortless. (So much, in fact, did thr; bike enjoy these shifts that once or twice it tried to do them itself, but managed to get no further than halfway, leaving us coasting along in neutral.)

Final drive is by fully-enclosed chain which runs in a grease-filled enclosure with expanding rubber bellows to allow for chain adjustment. Cush drive arrangement is normal for chain driven bikes, operating through five pairs of opposed rubber blocks in the hub.

The motor fires up easily from cold, heats up very quickly and won't idle when warm unless the handlebar mounted choke is fully off. Yamaha claim to have solved all the overheating problems often associated with upright in-line V-twins simply by offsetting the cylinders slightly, attaching a black air scoop to the right-hand side panel and cunningly ducting the hot air past the monoshock unit behind the rear cylinder — where else would you expect it to go anyway?  to exit just for'ard of the back wheel.

Despite this  and a couple of very convincing infra-red photos that Yamaha have produced to prove that heat build-up is no greater in the rear cylinder than in the front  I remain, yours truly, unconvinced. When I had possession of the test bike, it seemed to me that the rear cylinder was running considerably hotter than the front, and after one particularly gruelling spell in slow city traffic the rear pot cut out entirely in a flurry of pops and bangs and would not consent to fire up again until it had been allowed a ten minute cooling-off period. This only happened the one time, though.

Once in motion, the engine displayed an admirable ability to rev effortlessly through the gears, reaching its 7000 red line with deceptive ease and no complaining. Maximum torque occurs at 5500 and maximum bhp at 6500, and the bike will pick up from very low revs, with no detectable power bands or flat spots.

The cast italic rear wheel is mounted on a tubular section swinging arm which pivots on the rear of the engine casing. This is suspended on a monoshock unit derived from the Monocross system used on Yamaha's motocrossers and the 250 and 350LCs.

Like these, it incorporates a temperature compensating device designed to accommodate for those changes in operating temperature caused mainly by the unit's proximity to that hot rear cylinder. This works by using an expanding magnesium rod to restrict the movement of the damping oil  as the unit heats up and the oil thins, the rod expands and cuts the size of the opening through which the oil moves, thus maintaining even damping.

Damping is remotely adjustable in six stages from a knob attached to the subframe below the seat which is connected to the De Carbon type monoshock unit via a cable. The cable can also be adjusted at the other end, though the men from Mitsui say this is not the official company line and is therefore inadvisable.

There is no spring preload; instead springing is air assisted and the air cushion is adjustable from a valve beside the damping knob. Pressure can be increased using a garage air line or a foot pump, and can be set at anything between 7 and 57psi at the back, the 'standard' being 14. We found that pumping it up to 17psi improved the back end for solo high speed travelling.

Air cushion adjustment at the front was a much more tricky and annoying business. Whoever it was who decided to put the valve nipples in such a position that you have to remove the handlebar before you can fit the line on ought to have his bottom smacked. Even with this done we found it very difficult to get the footpump nozzle on securely and even more difficult to get equal pressure in each fork. And another thing, Yamaha, the dustcaps over the nipples kept falling off . . .

The TR-1 handled reasonably well in dry weather. The low centre of gravity of the engine/frame arrangement means that there's a low moment of inertia about the roll axis and therefore that keeling over to corner is a pleasantly effortless business. In fact, the Yamaha launch publicity blurb makes much of the fact that the bike's 'light' weight — 4851b compared with 467 for the Honda's CX500 and 485 again for BMW's R100/S  and consequent deeper lean angle 'helps to increase the pleasure of sport riding'.

Ha so? Seems to me that the handout should also warn unwary journalists that finding a deeper lean angle is severely hampered by the bike's aggravating tendency to ground its centre stand rocker lugs.

If the story that traces the origins of the TR-1 back to Yamaha NV in Amsterdam is the correct version of events, there must surely be more than a grain of truth in the rumour that Japanese bikes are no longer designed according to the dictum that 'It never rains in Southern California'. Can the same be said of the tyres?

A tyre dealer told me that though once upon a time Japanese tyres were designed only with the Great American Marketplace in mind  that, is they were very hard wearing but had poor grip in the wet — nowadays the Japanese tyre designers work with an eye on the World's Second Greatest Motorcycle Market (Europe, don'tchaknow?), the consequence of this being that current Japanese covers are almost as good as their European-made counterparts.

Oh, really? Well if the Bridgestones on the TR-1 were anything to go by — and I suppose I ought to point out here that the company makes a vast range of different motorcycle covers — my dealer was talking through a hole in his crash helmet and the Japanese tyre designers have one hell of a lot to learn.

For though the TR-Ts brakes were excellent wet or dry (twin discs front, drum rear, no wetlag anywhere), the rear cover simply refused to stick to the road even under comparatively mild wet weather braking, an opinion confirmed by one of my colleagues who found himself in the most alarming Brakin' Quandry (geddit?) when the rear wheel locked up and the tyre lost its grip.

This all came to a dangerous head when I took the bike out on the poorly-surfaced narrow high-speed test circuit at MIRA. It was raining heavily the day I went, and at high speed on the uneven bumpy surface the bike wobbled insanely, uncontrollably. And when all that's keeping you upright at plus-ton speeds is the gyroscopic effect of all those spinning bits and the fickle finger of Lady Luck, it's time to quit. That's what I did. My top speed was a mere 106mph, and though the bike, must be capable of a good bit more I wouldn't chance it.

Not on those tyres.

At MIRA.

In the wet . . .

An unf aired bike  no matter how spacious the seat or how relaxed the seating position — will never be as comfortable on long trips as the same bike with a fairing, however comfort can sometimes be pretty much a matter of what you're used to, what you prefer and how tall you are. Editor Dave Calderwood, who tops off at 6' 2" found the TR-l's seating position fairly tiring at 80-90mph cruising velocities, while I (5' 10") found it no bother. Then again some commentators have found the front foot pegs a few inches too far forward for long distance. Not me  I found them ideally located.

The slightly stepped dual seat is soft enough and spacious enough to make two-up riding more than tolerable, and there's a heavy box-section grab-rail for the passenger. Instruments and idiot lights are clear and easy to read, and switchgear — in all the normal places is as convenient for operation (or as inconvenient) as is usual.

The only thing the bike lacks for comfortable long distance touring is a fairing, and I'd place a bet that that'll turn out to be the purpose of that suspiciously vacant extra lug at the front of the engine. Any takers?

There have been one or two gripes in the motorcycle press so far about the TR-l's fuel economy — or the lack of it. I find this surprising. We got 4S.2mpg under fast, hard riding and a normal riding average of 46.S. This compares with 45-46 for the R100/S and a miserable 44 for the CX500, so the bike seems to be well up with the competition.

T'ain't possible to say much about reliability after a two week roadtest of a brand new model  for that we'll have to wait — however Yamaha have ensured that periodic maintenance, that bugbear of high mileage tourers, shouldn't be too much of a problem.

The final drive chain enclosure incorporates a small window through which you can check chain tension — the recommended adjustment interval is 4000 miles with an anticipated chain life of 30,000 miles. Oil changes should be done every 3000 miles, the left-hand crankcase having a small window to check the level. Ignition is of the transistorised electronic advance variety and as such should not require adjustment.

Yamaha have made a ten-year prediction of model Life for the TR-1 and its derivatives, though it has been produced to a deadline of only two years. The owner's manual disclaimer takes on a mysterious significance — 'Some data in this manual may become outdated due to improvements made to this model in future

You bet it will. And fast. Like all new models it will be so much better after a couple of years' refinement that early buyers will wish they'd been a bit more patient. Or maybe not. After all, the bike is a real traffic stopper at the moment and if you want to be a flash poseur for six months or so go out and get one right now. Kids on push bikes will stop and stare. Taxi drivers will hang out of their windows for a chat  'Is it really lOOOcc, mate?' Old gents with eyes misty for their long-gone Vincents and Zeniths will tell you it's the bike of their dreams, son, but I don't think I could manage the weight anymore.

There are some neat touches to the big V-twin  for example, like the XS1100 tested elsewhere in this issue, it comes complete with a safety chain and padlock.

However there are some nasty bits too. What about that ugly back end, for instance, with the mudguard clipped to the swinging arm? What about that plastic. . . er, thing, beneath the steering head which has no discernible purpose other than concealing the engine mountings?

And then there's the whole question of engine cooling and that cheapo black air scoop glued to the right-hand side-panel. These quirks of Japanese technology run to overtight deadlines surely won't survive for as long as the model's projected useful life.

Will the model itself last that long? Only time will tell the answer to that question. It's worth noting, however, that though when I was in Germany recently I saw more than a few of the big Yamaha V-twins, most of them were 750s and only a smattering were TR-ls. The bike is an ugly beast when compared with its smaller stablemate, but that shouldn't bother all those sporty tourers or they wouldn't buy CXs and Bee-Ems, now would they? ■