Over to you, Bologna...

Words: Alan Cathcart
Picture: Gold & Goose

More than 64,000 examples of the TDM850 sold in the past decade since its 1991 launch - new version goes on sale in January 2002. Alan Cathcart was at the launch.

You had to give them marks for trying, but it was still impossible not to smile.

At September's Milan Show, Ducati tried to underline the growing diversity of its desmo V-twin range by displaying chief designer Pierre Terblanche's Multistrada "polivalente" prototype, due for production in 2003. It's a bike which (and I quote from the official Ducati press release) "introduces... a new concept in motorcycling. The Multistrada combines sportbike performance and design, with all-round abilities".

You have to wonder if whoever wrote this really believed it. If they did, give them a D-minus grade in motorcycle studies.

For just one week later at the Paris Show came a reminder that the Italian company indeed did not invent go-anywhere sportbiking, when Yamaha unveiled its latest take on a versatile everyday motorcycle first released 10 years ago - the new TDM900 parallel-twin.

Originally launched as a multi-purpose all-rounder derived from the Dakar-winning XTZ750 maxi-enduro, more than 64,000 TDM850s have been built in the decade since, establishing a market niche in much the same way Ducati's own M900 Monster did in a quite different class around the same time. Like the Monster, the TDM has proven immune to imitation by Yamaha's competitors.

The recent plethora of dirt-derived tarmac trailies on the market still doesn't hit the same spot the TDM always has. Sales of the world's only true "moto totale" have continued to be bullish, especially after a 1996 revamp adopted its TRX850 sporting sister's unique 270-degree crankshaft throw with a sympathetic restyle. The TDM850's best two sales years came in 1999-2000, when 10,000 bikes found homes in Europe and Australasia. Yamaha's decision to give its still-unique concept a 10th-birthday makeover will see the TDM900 on sale in dealerships around the world in January.

Well, everywhere except the USA. You gotta feel sorry for the American biker, deprived of the chance to buy one of the world's most practical and unique motorcycle models, which embraces the word "versatility" like no other bike yet built for sale.

Yamaha has retained the same liquid-cooled 10-valve parallel-twin dry-sump engine (with cylinders inclined forward by 45 degrees and chain-driven dohc) introduced in the 1980s as a 360-degree 750, bored out to 848cc in 1991 for the first TDM, then converted to 270-degree crank configuration five years later. This has now been bored out a further 2.5mm to 897cc, but retains the same stroke (so, dimensions of 92x67.5 mm) for 5% more power (now a claimed 86.2bhp at 7500rpm) and more than 11% more torque right through the rev range, peaking at 9.1kg/m at 6000rpm. With the same crankcases and a modified 270-degree crankshaft, the overbore requires a new cylinder block and cylinder head with 10.4:1 compression ratio, as well as various up-rated engine internals designed to reduce weight and increase power. New lightweight re-profiled camshafts offer greater valve lift and longer dwell.

Carburised conrods are not only stronger, but also 12% lighter than before. Re-designed forged pistons run in ceramic-composite plated cylinders that are lighter, improve cooling and thus accommodate a smaller water radiator. The distinctive circular pressed-steel oil tank mounted above the gearbox gives way to a new 23% lighter one with the added benefit of an oil-level sensor.

There's also an all-new six-speed gearbox with a lower bottom gear and higher top than the previous clunky five-speeder, but with closer ratios to improve performance. Fuel injection has now been adopted for the first time, with twin 38mm Mikuni throttle bodies and a Mitsubishi ECU that also controls the innovative variable-operation air intake duct monitoring the volume of air entering the system. A single injector per cylinder is located beneath the throttle butterfly, closer to valves that remain the same size. Finally, the new twin-silencer stainless-steel exhaust system features twin catalysts, enhanced by a compact new air-induction system that feeds air directly from the airbox through the cylinder head and into the exhaust ports. This secondary airflow accelerates oxidisation of exhaust gas particles, improving the catalytic converters' efficiency and allowing the TDM900 to comfortably meet strict new Euro-2 emission standards.

The resulting engine package sits in an aluminium twin-spar frame, much stiffer and lighter than the old TDM850's steel chassis. A detachable rear subframe, neatly integrated into the overall design, offers a 825mm seat height and revamped suspension. The fully-adjustable rear shock with rising-rate link still has 43mm conventional forks, but they're adjustable only for preload and rebound damping, and are set at a 25.5-degree head angle (compared to the TDM850's 25 degrees) with 114mm of trail (was 105mm). The new chassis is a massive 29% lighter than previously, which helps reduce the TDM900's dry weight by no less than 11kg to a claimed 190kg. With the engine located slightly further forward and more upright, weight distribution is 50/50 between front and rear axles, rather than the rearwards bias of the old TDM850. The aluminium swingarm is also 40mm longer, which promotes improved traction, a more centralised mass and, in turn, enhanced handling. The 18in front and 17in rear wheels are both wider and lighter, with thicker 298mm-diameter front discs now gripped by the same four-piston monobloc Sumitomo brake callipers used on the R1 and R6 sportbikes. Dunlop's new D220 Sportmax multi-purpose rubber is fitted as standard.

A slimmer 20-litre tank and restyled bodywork aim for better protection than the old model, says Yamaha. Combined with a longer 1485mm wheelbase and that rangier steering geometry, the new look underlines the model's touring rather than sporting pretensions.

The chance to test those claims came at the bike's press launch on Spain's volcano-encrusted Canary Island of Fuerteventura. The setting underlined the TDM900's credentials as one of the world's great go-anywhere rides, simply because it does everything you ask of it very acceptably and many things very well. This is truly a bike for every type of road condition. After a day riding 300km up and down mountains, along deserted desert roads that would do a Grand Prix circuit proud, trailing along dishevelled dirt tracks, or crawling in traffic through a twisting, corrugated mountain pass, it's clear Yamaha has made an already excellent package even better.

Slinging a leg over the TDM900 is as convenient as before for anyone of average height, even with a 30mm-higher seat that provides the same excellent view of the countryside around you. The ultra-comfortable, upright stance is great for monitoring traffic flows ahead, with good leverage from quite wide handlebars with big balance weights in either end. The gear-driven balance shaft at the front of the engine means the only slight vibes you feel are through the footests at anything over 6500rpm. That's not a factor on a bike that combines the trademark exhaust drone of a parallel-twin and the offbeat lilt of a 90-degree V-twin to sound like nothing else on the road.

The restyled bodywork has the rear of the fuel tank narrower than before, even though it's a litre bigger in capacity. The reshape allows your knees to tuck quite nicely into its flanks in a rational and relaxing riding position.

It's a nice place to spend a day, because the relatively rearset footrests and fairly plush seat pad help reduce saddle-soreness after a long run.

Although the screen-cum-wind deflector isn't that high, its angle flows most of the blast over a six-footer's helmet and around his shoulders, ensuring you don't get buffeted about unduly at speed. Two optional screens, 80mm and 150mm higher, are available as part of the extensive TDM900 accessory package, which also includes FJR1300-inspired hard luggage with detachable liners, heated handgrips and a factory-approved alarm that will cut your insurance premium.

Most owners really ought to fit the optional main stand, especially since there's already a humungous amount of ground clearance and you have to work really hard at decking the long hero tabs on the flipup footrests. The sidestand is a good one, though, with a well-positioned tab making it easy to use.

The rear view mirrors are superlative - zero vibration, great visibility and they look quite good, too. Same goes for the redesigned dashboard, with a central analogue tacho with digital clock in its face, a water temp gauge on the right and a digital speedo on the left, adjustable for miles/km. A trip and very truthful fuel gauge are also extremely readable and classy-looking.

Passenger accommodation cleverly incorporates handgrips in the neat, but quite small, luggage rack out back and the relatively low-set companion footrests are possible thanks to the low placement of bigger twin-exhaust silencers. The only thing Yamaha has left out is a convenient way of altering the preload on the rear shock for when you carry a passenger or some heavy luggage. Instead of an easy-access external knob like on the Aprilia Futura, you must attack the shock with the C-spanner carried in a quite complete toolkit. Pity!

That adjustable rear shock delivers 133mm of rear-wheel travel, combined with 150mm at the front from cartidge forks adjustable only for preload and rebound. But effiacy of the R1-type front brakes made the standard suspension settings at both ends too soft, even for a solo rider with no luggage. They stop the TDM brilliantly, with great modulation on the lever when you need it. But under repeated hard braking hard through winding mountain passes or along twisting country roads, the soft suspension loses shape when you grab the five-way adjustable lever, then release it to get back on the power again. The weight transfer sends the bike pitching back and forth, a problem easily resolved by stiffening up the four-position front rebound damping to maximum, then doing the same within four clicks of maximum at the rear.

Adding a turn of preload to the rear shock completed the job, and made the TDM much better behaved on and off the gas, without compromising the long-travel suspension, which ate up the worst that Fuerteventura's roads threw at it.

Serious angles of lean are possible from the pretty capable D220 Sportmax Dunlops and the even weight distribution allow quite high-speed cornering without any strife. The TDM900 feels slim and agile at slow-speed corners, but planted in faster turns. That new, more conservative steering geometry definitely gives extra stability, without making the Yamaha heavy to steer. Nice.

But if you just want to go with the flow and tootle along in traffic, the TDM allows you to chill out as happily as it will put on a race face, with the smooth-action cable-operated clutch picking up easily in a line of cars.

That's when you encounter the single greatest improvement over the old TDM850 - the gearbox. Instead of the clunky change and occasional transmission snatch that marred the old model, the new bike's six-speeder changes faultlessly, provided you use the clutch for upward shifts. Trying to do so clutchlessly still produces a harsh, rather notchy action, but doing so "properly" is much smoother, if a little slower. That really isn't an issue on this kind of a bike.

That's because the big-bore engine has a mile-wide powerband and an ultra-flat torque curve that makes it pointless to shift gear more than necessary, especially with a sweet spot as wide as 4500-7500rpm. There's a notional 9500rpm revlimiter, but nobody in their right minds will ever encounter it, since the 10-valve engine pulls hard and clean above 3000rpm, providing loads of lazy torque and more than enough power for the TDM's purpose. The six-speed gearbox is not only quieter and less graunchy in operation, it also has a much better choice of ratios than before, closer but still evenly-spaced with an average 900rpm between changes. Combined with the 86bhp on tap, that gives the TDM900 reasonably muscular acceleration. But the real strong point is a midrange roll-on from 4000-7000rpm that, together with the crisp pick-up from the fuel injection, makes this a great bike for twisty roads.

Yamaha's decision to locate the single injector per cylinder south of the throttle butterfly means the TDM isn't as snatchy in mid-turn as other fuel-injected bikes with an external injector, especially when you open the throttle again after a tight bend. There is still a slight jerk, most noticeable on a loose surface, but really this bike is best treated as a totally tarmac tool.

Performance at the other end of the scale is excellent for a real-world sportbike, with surprisingly comfortable ton-up (160km/h) touring with the tacho needle parked effortlessly on 6000rpm. But wind it up to 200km/h/120mph at 7000rpm and you'll be exercising your arm muscles unduly, especially if you go for the 227km/h/142mph indicated top speed I saw with the revcounter needle just creeping into the 8000rpm red zone.

Pretty pointless, though, For if ever there was a versatile, go-anywhere sportbike that excels in real-world riding conditions, where the fun of attacking a switchback mountain pass or a fast, sweeping B-road is more important than setting off speed cameras, the Yamaha TDM900 is it. This is a refined, hard-to-fault version of a bike that has already established a design benchmark no other manufacturer has yet succeeded in copying.

Over to you, Bologna. It's your turn to try... but beware, Yamaha just raised the cross bar for you.