The simplest way to get a big discount on a new bike is to turn up at the nearest multi franchise dealer in the middle of December with a wad of used fifties in your underpants. Works every time. A few hours later I emerged with a brand new TDM850 Yamaha and over four grand poorer (one hell of a big pile of fifties). I had ridden a friend's and been immediately smitten by the huge production of low speed torque. It had more grunt than a 850 Commando, knocking out 58lbft at 6000rpm as well as 78 horses at 7500rpm.
My friend had impressed me by taking off rapidly in fourth gear with hardly any clutch slip! The brand new five speed gearbox was both loose and stiff at the same time; requiring a hefty boot that only rarely managed to put the bike in gear - it soon became obvious why he liked taking off in third or fourth, the gearchange action was so horrible that he had no choice. I consoled myself with the thought that the box would surely get better when a few miles were put on the clock.
The riding position was relaxed for town riding and we chuffed along happily enough the 50 miles to my humble abode in Walsall. The lack of protection afforded by the plastic was par for the course. I hated the twin headlamp binacle perched below what would otherwise pass for an attractive half fairing.....if only Yamaha had had the guts to dump the plastic altogether I am sure the bike would have looked all the better for it. My hands were frozen solid, useless clumps of leather and flesh, by the time I arrived home.
I have always liked big vertical twins, having been brought up on various Triumphs and Nortons but I soon tired of their lack of reliability. I also owned an XS650, a fantastically reliable machine but slow and awful handling. With a dry weight of 440lbs the TDM was lighter and endowed with a vastly superior chassis, as well as much more power and torque, so some progress has been made.
To my mind, 440lbs is excessive for a vertical twin, even a 850cc one. Yamaha make a 600cc four that weighs less than 400lbs so I would have thought that the TDM could lose a 100lbs if they put their mind to it - just chucking the plastic and the massive exhaust system ought to save 75% of that! On the road, though, the Yam does not feel like a 440lbs, it manages to combine the light feel that its trail bike look might suggest with an overall feeling of security that is well at odds with its long travel suspension.
A lot of this must be down to the rigidity of its steel Deltabox frame, the narrow, relatively low slung engine dispensing with the need for lower frame members. The cylinders are radically canted forward as per FZR fours, although the way the clutch and gearbox are tucked upwards make the engine look like the whole unit has just been twisted through the vertical. High technology freaks will be relieved to see that the motor is watercooled and that there are five valves per cylinder.
After 500 miles of mild running in, a period over which the vibes noticeably diminished, only a 4250 to 5000rpm range was left that was reminiscent of running a 650 Bonnie at around 6500rpm. A hundred miles of cruising at, say, 85mph, would thus lead to dead fingers and fading vision, although much to my relief it showed no sign of imitating its British brother by either depositing essential bits of chassis on the road or self destructing.
The engine features balancers, of course, but no one has yet explained to me how engine balancers work.....yes, you can get them to cancel out primary imbalances at one point in the combustion cycle but at other points they produced there own vibration. I think what happens in the case of the Yamaha is that reciprocating masses are minimal, crankshafts are dynamically balanced and what vibes are left are redirected from the vertical to the horizontal by the balancers where the frame and chassis can more easily damp them out.
It used to be an old and secret art, designing frames to soak up the worst of vertical twin vibes, but judging by the smoothness of the TDM at all over revs, one that Yamaha has cracked. Perhaps their experience with the old XS650 helped, that had such excessive mass that most of its vibes were soaked up (although it could never attain the levels of smoothness associated with the TDM)....perhaps if the TDM lost that 100lbs it would become as bad as the old Brits!
The most outstanding feature of the TDM, I have found in the last 6000 miles, has been its torque. A total idiot could ride one, it almost makes the idea of an automatic gearbox redundant, at most it just needs two gears! The gearbox has become easier to operate and slightly more precise but it is ridiculously easy to miss gears when changing down. The clutch is light enough to hold on all the time at traffic lights as an alternative to spending fruitless hours searching for neutral.
Acceleration in the lower gears is phenomenal. Just opening the throttle in first or second is sufficient to have the front wheel pawing the air; even hard acceleration out of corners in third causes the front end to go light, the bike driving across the tarmac as the front wheel patters over the road. It catapults up to 110mph faster than my brain can happily cope with, then slows somewhat up to an indicated 135mph. It will cruise tirelessly at the ton all day, the engine out of its rough spot and remarkably smooth for an 850cc vertical twin (better than a Commando).
The Dunlop tyres stick to the ground with tenacity and the suspension has shown no signs of wear so far. Adjustable preload and damping is available at both ends and I've managed to set mine up on the soft side of firm. It eats the potholes with ease yet doesn't allow any wallowing in either a straight line or through the bends. This paeon of praise was somewhat ruined by the seat, which was not as comfortable as it should have been and produced a sore bum after a 100 miles.
With a seat height of 32" it's passable for those short of leg and the reasonably placed footpegs allied with slightly higher bars than I would have liked were otherwise comfortable enough for 150 miles of fast road work and a blessed relief, in town, after the cramped arrangements of a race reptile I had been previously posing around on. The 850 will stay with 600 replicas on twisty roads, only losing out on fast A roads. The big difference is that the TDM is the kind of bike that adapts to how you want to ride rather than dictating the pace. Its excessive torque below three grand means it will meander along in BMW style; most relaxing and almost economical at 50mpg. The other side is using the throttle a bit, although not excessively, past 7500 revs power begins to tail off dramatically, although out of interest I have had the engine in the red in the lower gears. Used to the frantic gearbox action of across the frame fours it took me a while to adapt to just opening the throttle but that feeling of gut wrenching acceleration was wonderful. Not so wonderful was the 39mpg that resulted.
It made me wonder how I had ever given up my Commando for the dubious delights of a Honda four. That's where the TDM shines - it's taken all the attributes of the best of British vertical twins - excessive torque, narrowness, flickability - and added to them even more grunt, compliant suspension that is perfect for our ruined roads and rock steady handling. Compared to the old Brits its 50lbs too heavy and nearly 20mpg down on fuel (the TDM averaged 42mpg under my hands) but this is only the second version of the engine (the Super Tenere was the first) and it may get better in years to come. I can't wait to get my hands on an aftermarket exhaust which will certainly lose mass and may help economy.
The consumables have been pretty good, still plenty of life left in tyres, pads and chain. Engine servicing is easy enough for the DIY fanatic (my experience of dealers had been such that I feel it's better to put a match in the tank than hand over the machine for a service). 10 valves is excessive but the upside is that they have required no adjustment from new. I change the oil and filter every 2000 miles just to be on the safe side. Yamaha build really tough four strokes, these days, so I have no qualms on longevity. Even the finish has held up well through the winter with only a few spots of rust on the rear subframe and exhaust.....but with a new bike I'm pretty fanatical about cleaning and polishing.
There are a few on the used market now, but nothing much under £3500 - if Yamaha were selling them for around that new they could probably move a few hundred a week but at a retail of over five grand I can't see many people buying them. I certainly wouldn't have unless I could have got the big discount I did; now that I've bought it, though, I've got no intention of selling her.
P.B.