Monday 10 August 2020

Yamaha TR1

An ode to insanity, came to mind when I bought the early eighties 981cc V-twin. As someone who'd majored in replicas for the past few years buying what the UMG likes to term a proper motorcycle might seem a bit strange. But sudden loss of job meant either the CBR900 had to go or the house would be confiscated by the bank. Still, the choice was a very close run thing, indeed!

Reality was 70 ponies and 490Ibs of real iron. In fact, the TR1's power peaked at 6500rpm, a point at which the CBR was just beginning to become interesting! First impressions were of a rattly, vibratory, motor, a chassis that was about as sophisticated in feel as your average tractor, and, er, an amazingly comfortable perch. A few years on the replica had made me forget just how comfortable were normal motorcycles when properly rendered.

Everything on the Yamaha required extra effort. There was no point pissing around with delicate inputs, the old dear would just shrug them off and carry on as before - whether trying to change direction, brake or work my way through the gearbox. Muscle and force definitely needed.

After adapting to this, the TR1 was a relatively easy bike to ride. Much of my time was spent in heavy city traffic where I didn't really miss the Honda's manic acceleration - honest! The 29000 mile engine rumbled and grumbled away but delivered plenty of low rev torque and power. The gear change needed a hefty boot but was actually more precise and definite than the CBRs, with none of the latter's false neutrals - mind, the Honda had done more than 53000 miles of high speed riding.

After the ultra-quick turning 900, the Yamaha was very stately in feel, needing a lot of effort on the flat bars. The engine was mounted exceptionally low for a Japanese machine but the forks were quite kicked out and the wheelbase long. Thus the bike never felt entirely stable yet didn't have the flightiness of a replica’s front wheel.

The bike didn't react to the idea of excessive speed very well. Beyond 80mph the front forks went all spongy and the rear shock lost its composure. The bike wallowed along rather than weaved or wobbled, only really feeling like it was going to die a death when a large bump or hole was hit. The big but scrawny Taiwanese tyres weren't sure if they were coming or going, and wet weather could turn it all quite frightening!

The mono-track back end promised some kind of passing modernity but a few miles showed that its bearings were shot. This was revealed when the bike went into an alarming speed wobble just as I pushed the reluctant engine past the ton. The engine's used as a major part of the spine frame, always communicating some of the combustion process to the rider, turning rough once past 6000rpm. They must've been thinking about Vincents when they laid down the plans for the chassis.

The chassis rigidity fought with the suspension's looseness, only won out after I'd almost hit the side of a car! Panic slowly abated, the stress on the chassis so warping the bearings that it'd become a rolling deathtrap even at abysmal speeds. So bad that those nice guys at the AA had to be summoned!

The first problem with the swinging arm was actually getting at it, had to take the exhaust off, which revealed an excess of rust on the inside of the silencers. I had visions of them falling apart as I rode along, the venerable V-twin already making a racket that put to shame the average sixties British twin. The downpipes weren't too bad, so the usual bodge of a couple of universal cans was employed - but only after cutting up an intermediate couple of tubes (from an old Suzuki GT500 exhaust) to take into account the run of the existing system. Carburation was barely affected by this affrontery!

Back to the swinging arm. The actual spindle popped out without too much hassle but the top bearing had corroded in and was only rudely ejected after putting the arm into an hydraulic press (thank you, brother!). The rear shock was taken to the breakers where a slightly longer match was found, that had much firmer springing.

As I'd found the front disc totally wimpy I had a look around for a potential front end replacement, ending up with stuff meant for a CB1000N! Fitting it all back together blew most of a weekend, differences in the fork yoke sizes had me scratching my head until brother came to the rescue with some sleeves and a new top yoke! Very useful having a close relation with a workshop!

With the back end slightly raised and a lower front end, geometry was moved in a more sporting, quicker turning direction whilst the suspension felt absolutely rock solid. In fact, the front end flopped around so uselessly on its stock springing that the TR1 only ever had a vague approximation to the designer's intended steering geometry. 

I felt much more at home on the transformed TR1, especially enjoying the new found braking forces - just a gentle caress with one finger had the front tyre screaming for mercy! As might be imagined, though, there was now a massive mismatch between the back Taiwanese condom reject and the front, ultra sticky Metz! However, as the latter only had 500 miles life left it in, an ultimate compromise was found in a slightly used pair of Avons.

Having sorted out the chassis to my liking, I then had to contend with a motor that kept cutting out. I'd inadvertently loosened a connector in the main ignition circuit - I think I tore about a third of my hair out before I sussed it! This era of Yamaha had dodgy cut-out switches but they had all been taken out of the circuit and even the starter motor had been modded to avoid its well known tendency towards self-destruction.

That wasn't the only electrical problem | had. A little way down the line, the battery began to falter. I dug it out, finding half the plates full of white crap. The breaker was visited and a likely candidate found. This popped in OK but only lasted a couple of days, most of the acid burned off, the plates warped. Digging into the ancient electrics I found a non-standard rectifier/ regulator and some weird wiring. Bore no relationship to the wiring diagram in the workshop manual.

It's a waste of time asking breakers for TR1 parts, they usually assume it's some old Triumph car! MCN turned up a guy who was breaking one... I was the first one to phone up after the ad had been in for two weeks. His seized motor was in a million bits but the rest of the chassis was intact. I could have the lot for a hundred quid. Gor, that's cheap, thought I. It wasn't, the chassis had almost completely merged with the greenery on his garden wall. In the end, I agreed to take it away for free! Luckily, the black boxes had been thrown into the crate with the engine bits and they worked OK after I sussed the wiring out!

Engine maintenance wasn't much of a chore. Every 1000 miles, or so, fiddle with the carbs, adjust the valves and change the engine oil. The top ends are similar to that on an SR500 but seem longer-lived, tend to go from rocker demise around the 50000 mile mark. Crankshaft life depends on frequency of oil changes, neglect a few of those it'd soon be in trouble. TR1 engines can be surprisingly rugged and long-lived, also full of character!

With everything set up nicely, I could eke out a gallon of fuel for more than sixty miles, although it needed half a pint of oil every week, or around the 200 mile mark - didn't dribble so it must've just been down to the well worn clearances in the cylinder. The bike's distaste for high speed cruising, as in anything over 90mph, was shown by fuel no better than the CBR around 35mpg!

Despite being naked, the TR was pretty comfortable up to 90mph, someone had thought about the relationship between bars and pegs (not that common back in the early eighties) and the seat/tank interface suited my rather squat body. After about seven months a brief blast on a CBR600 reminded me what I was missing - power, sophistication and ease of use. Leaping back on to the TR1, the poor old thing felt so agricultural that | felt sure it was going to fall apart under me. A couple of hours was all it took for the ruminations to fade into the background.

After about eighteen months, more than 25000 miles, the bike and I have become firm friends. It's very dependable, very useable (especially after the suspension mods) and quite cheap to run - tyres, for instance, last two to three times as long as the CBR. Alas, once the high rev, outrageous power and totally berserk speeds of a modem Jap replica gets in the blood it's hard to forget - with improving finances, I'm going to be able to afford an R1 soon. But the TR1 will remain as my second bike, winter commuter.

John Williams