The following is a re-edit of a piece posted by MotorMartin on DriveTribe under the I Love Motorbikes banner run by Tony Yates, perhaps better known as @Xinterceptor.
There was a time in the early nineties when it appeared that motorcycle design and engineering was stagnating. There were the Sportsbikes of course, powerful yet with frames and suspension that could barely keep everything under control, commuters that offered reasonable economy but twenty year old styling and a variety of singles and twins that, far from offering an alternative, were awful enough to push the consumer away from motorbikes in the first place. Yes, there were some aging two strokes trying their best to keep things interesting and delivering their beautifully pungent blue smoke upon the highways and byways of this green and pleasant land but for the majority, motorcycling was in a downward cycle.
But not everyone was downcast with Yamaha keen to look into and develop something new, a class of motorcycle that would perhaps introduce that spark that many of us look for when choosing a new bike. And this is what they came up with, the criminally underrated TDM850, perhaps the first time that the thinking behind a trail bike had been combined with a sportsbike in a bike created for the mainstream. An adventure bike in the manner of the latest Triumph Tiger 800 XR range, 25 years before Triumph got theirs out of the door.
Yamaha got it right first time with the TDM, especially in Europe where the Yamaha was the second-biggest selling 750-1000cc bike from 1991 to 2001 and yet it wasn’t such a hit in the UK despite contemporary reports reviewing the Yamaha favourably, even going so far as to label it a Sportsbike beater. So what was it that our more enlightened European cousins could see that us Brits could not?
The TDM was a thoroughly modern creation and one that broke new ground for many riders this side of the channel, motorcyclists perhaps less open minded than the Yamaha’s more natural target audience. At it’s heart was an all new water cooled, 849cc, parallel twin, DOHC, 5 valves per cylinder engine producing around 75bhp at 7500rpm and torque of 55 ft/Ib at 6000rpm, an engine that combined the quick revving nature that Yamaha was rightly well known for and the traditional torque of a twin cylinder machine. All in all, this was a great motor and one that suited the TDM down to the ground providing the rider with plenty of low down stomp for real world riding whilst retaining a top end rush right up to 129mph if you tucked in tight enough.
With it’s pressed steel perimeter beam frame, similar to Yamaha’s Sportsbikes of the time, the TDM utilises it’s twin cylinder engine as part of the chassis which, when combined with 41mm telehydraulic forks, adjustable for preload and rebound and monocross single DeCarbon type shock, enabled the Yamaha to hold fast in the corners despite the raised, trail bike style riding position. Far better than you might expect and with good suspension and brakes, for the time, makes the Yamaha TDM850 a genuine sports bike for the road whilst also providing a ride quality that is more than good enough as well.
What the TDM did so well was to create a new class of motorcycle that could be all things to all men/women. A bike that actually managed to provide the rider with that most rare of qualities. A machine that could take you to work and back in comfort during the week whilst still providing more that’s enough ability to thrill at the weekend, the engine and deltabox style frame working together beautifully. This in itself gave Yamaha a problem. With the relentless pace of progress pushed upon the consumer by the big four Japanese manufacturers and their rapid refresh rate, Yamaha needed to find a new angle for their 850 whilst still providing the rider with the qualities that had made the TDM such a good bike (if not good seller), in the first place.
The original TDM, produced from 1991 until 1995, sported an overall look was fresh and exciting, the twin headlights and half fairing blending well to provide illumination and protection whilst still suggesting sporting potential and aggression in equal measures. The traditional twin cylinder engine thudding away and allowing the tyres and suspension to dig in and propell you along your favourite B road. And then, in 1996, the clever folk at Yamaha’s R & D department caught everybody by surprise.
For the TDM’s first major update the most visual change to the bike was the replacement of the original twin headlights and fairing with Glynn Kerr styling and a smoother all-round look, a look that sought to appeal to an even broader fan base but perhaps one that also softened the overall image and toned down the original’ purposeful stance. The second major development was a change to the engine of the Yamaha. Still sporting a watercooled parallel twin cylinder engine, the TDM’s motive power now sported a 270-degree crank, an idea developed by Yamaha to give the bike a better connection between the rear tyre and the road itself, providing the rider with more grip and torque, much like today’s R1 and it’s much referenced ‘crossplane’ four cylinder unit.
Combined with the new engine Yamaha also allowed the forks an increase to 43mm and the radiator becoming slimmer, reducing the bike’s width and frontal area. The exhaust system was also redesigned to take advantage of the ‘big bang’ firing of the 849cc twin and on a practical note, the fuel tank increased in size to a far more useful 20-litres, allowing the TDM to stretch 200 miles or more from a tankful of juice.
The end result? A bike that still generated the core values that the TDM 850 had become famous for, a bike that looked great, performed even better than before with the characterful new firing order, excellent long travel suspension perfectly matched to the strong chassis and typically strong Yamaha brakes. What wasn’t to love?
And yet us Brits continued to ignore it. Yamaha’s biggest problem with the TDM? It was 25 years too early. Bugger.
Where will you go?