Cycle News - Archive Issues - 2000's

first TDM, then converted to 270degree crank configuration five years later. This has now been bored out still further by 2.5mm to 897cc, while retaining the same stroke (so, dimensions of 92 x 67.5 mm), for 5-percent more power (now a claimed 86.2 hp at 7500 rpm) and over l1-percent more torque all the way through the rev range, up to a maximum of 65.8 Ibs./foot at 6000 rpm. While retaining the same crankcases as well as a modified 270-degree crankshaft, the overbore has necessitated a new cylinder block and cylinder head with a 10.4: 1 compression ratio, as well as various uprated engine internals aimed at reducing weight and increasing power. These include new lightweight reprofiled camshafts offering greater valve lift and longer dwell, as well as carburized connecting rods that are not only stronger but also 12-percent lighter than before, fitted with a new design of forged pistons running in ceramic-composite-plated cylinders that are both lighter and help improve cooling - a fact which allows the TDM900's radiator to be quite a bit smaller than before. The distinctive circular pressedsteel oil tank mounted above the gearbox has been replaced by a new one, 23-percent lighter than previously, which also has the added benefit of an oil-level sensor. In addition, there's an all-new six-speed gearbox with a lower bottom gear and higher top than the old model's previous clunky five-speeder, but with the ratios in between closed up, to improve performance. Additionally, fuel injection has now been adopted for the first time on the new TDM, with twin 38mm Mikuni throttle bodies and a Mitsubishi ECU, which also controls the innovative variable-operation air intake duct monitoring the volume of air entering the system, with a single injector per cylinder located beneath the throttle butterfly, closer to the valves which remain the same size as before. Finally, the all-new twin-silencer stainless-steel exhaust system features twin catalysts, whose operation is enhanced by a compact new air induction system which feeds air directly from the airbox into the cylinder head, and thence directly into the exhaust ports. This secondary airflow accelerates oxidization of the particles in the exhaust gases, improving efficiency of the catalytic converters, which allows the TDM900 to comfortably meet the strict new Euro-2 emission standards. The resultant engine package is located in an all-new, aluminum twinspar frame, much stiffer as well as lighter than the old TDM850's steel chassis, with a detachable rear subframe neatly integrated into the over- From this point of view, you can see the fuelInjected parallel-twin engine with Its twin exhaust outlets, the 10ng-tr.Ivel suspension, the twin 2gSmm front discs (which share calipers with the R1 and R6) and the newly employed aluminum chassis that's 2g·percent lighter than previously. all design, offering a 30mm-taller 825mm seat height, and revamped suspension, including a fullyadjustable rear shock with rising-rate link - still with 43mm conventional forks, though, which are now adjustable for preload and rebound damping - not compression - 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-percent lighter than the previous one, helping to reduce dry weight of the TDM900 by no less than 24.2 pounds over the old bike, to a claimed 418 pounds, thanks to the engine being located slightly further forward and more upright than before, and it has a 50/50-percent distribution between front and rear axles, rather than the rearward weight bias of the old TDM850. The aluminum swingarm is now also 40mm longer than previously, taking a leaf from the R1/R6 book to promote improved traction and a more centralized mass, in turn enhancing handling. The 18-inch front and 17-inch rear wheels are both wider but also lighter than before, with 1mm thicker 298mmdiameter front discs now gripped by the same four-piston monobloc Sumitomo brake calipers as employed on the R1 and R6 sportbikes, and Dunlop's new D220 Sportmax multi-purpose rubber fitted as standard. A slimmer 5.2-gallon tank and restyled bodywork aim to deliver improved protection compared to the old model, says Yamaha, and coupled with a longer 59.4 inches wheelbase (against 58.8 inches before) and that rangier steering geometry underline the touring rather than sporting pretensions of the latest version of one of Yamaha's best-selling benchmark models. down mountains, doing the ton along deserted desert roads whose quality would not disgrace a Grand Prix circuit, trailing along disheveled dirt tracks running alongside goat farms, or crawling in traffic through a twisting mountain pass, often with a corrugated road service not yet the beneficiary of pork-barreled Euro-money, it's impossible not to conclude that Yamaha has succeeded in making an already excellent package even better. Slinging a leg over the TDM900 is no less convenient than before for anyone of average height, even with the 30mm-higher seat, from which you have the same excellent view of the road ahead - as well as the countryside around you - with an ultracomfortable, upright stance that is great for monitoring traffic flows ahead, with good leverage from the quite wide handlebars. These have big balance weights in either end, but thanks to the gear-driven balance shaft at the front of the engine, the only slight vibes you feel are through the footpegs at anything over 6500 rpm - not a factor on a bike whose distinctive combination of the trademark exhaust drone of a paralleltwin, mixed with the offbeat lilt of a 90-degree V-twin (thanks to the 270degree crank, concocted on Yama- TO OA MOON The chance to put those claims to the test as one of the first outside the Japanese company to ride the bike at the outset of its press launch on Spain's volcano-encrusted Canary Island of Fuerteventura, underlined the TDM900's credentials as one of the world's great go-anywhere rides simply because it does everything you ask of it at the least very acceptably, and many things very well. This is a bike for every type of road condition - what, a 'Multistrada' now, without having to wait until 2003? - which after spending a 190mile day aboard it riding up and cucle n e _ S • DECEMBER 5. 2001 9

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