Yamaha TDM850

Yamaha TDM 850

File:TDM850.jpg

Yamaha TDM 850 Facelift Model (Mk 2)

The Yamaha TDM is an 849 cc two-cylinder motorcycle, manufactured by the Yamaha Motor Company of Japan, that first came out in 1991. With a lot of torque, and 78 horsepower, it is considered to be a very good all-rounder.

Version History

The TDM 850 was the first motorcycle which was designed around the rider and not (as with most bikes in these days) as a bike with a buddyseat. Designing the TDM, Yamaha used a lot of ideas from their "Morpho" project. That is why the positioning of the rider on the TDM 850 was unique in these days and ideal for the longer (+ 1.80 mtr.)riders. Yamaha wanted to create a motorcycle which was capable of handling the mountain roads of the European Alps and that would cope with the sometimes not so smooth roadsurface.

It was imported into the United States for only two years, 1992 and 1993.

It was never a big seller in the United Kingdom or in The Netherlands but in countries such as France and Germany sales were very strong. In 1996 Yamaha released the Mk2 TDM with updated bodywork and a 270 degree instead of a 360 degree firing order. This upgraded engine was first seen on the Japanese market in 1995, when Yamaha introduced the TRX850. Thanks to this update, and the work of the Dutch TDM/TRX Club and in particular the founder and president Nico de Vroome, the TDM 850 became a popular bike in the Netherlands as well. (several years in the top 15 of most sold bikes)

In 2001 the 3rd incarnation of TDM arrived, the TDM 900 again with new bodywork, 6 speed gearbox, fuel injection, R1 derived brakes,reduced weight to 190kg dry, and a new smother 900 cc engine. Also it incorporates a diamond shaped aluminum frame & swinging arm.It has slightly wider tyres at 160 rear and 120 front. It has a 2 position trip meter, an analogue clock, and a horizontal bar graph fuel meter.It is available with ABS as an option.

The TDM is classified as New Sports a new class invented by Yamaha, but most of the people compare it with Dual Sports or Adventure Sports bikes. Its engine was derived from the Paris Dakar winning Yamaha XTZ 750 Super Tenere. Although too large and heavy for serious off-road work, the TDM has a long travel suspension and is well suited for gravel tracks and light off-road use. Most popular modifications include fitting aftermarket exhausts,R1 brake calipers, and dual sports tires.

Performance

Top speed around 220 km/h 0-100 km/h, around 3.8 sec.

Specifications

Yamaha TDM Twin 900, front view

Yamaha TDM Twin 900, rear view

Engine
Type	4-stroke, DOHC, liquid-cooled
	Forward Inclined Parallel 2-cylinder
Displacement	849 cc
Bore x Stroke	89.5 x 67.5 mm
Compression Ratio	10.5:1
Maximum power (claimed)	78 bhp 56.6 kW)@7500 rpm
Maximum power (True hp, measured)	60-62 true hp @7500 rpm, all stock
Maximum Torque (claimed)	8.1 kg-m @ 6000 rpm
Starting System	Electric
Lubrication	Dry sump
Carburetion 92-93 all locations	Mikuni BDST38/2 38mm CV type
Carburetion 94-97 all locations	Keihin CV type
Primary Reduction Ratio	67/39 (1.718)
Secondary Reduction Ratio	42/17 (2.471)
Clutch type	Multiple disc , Wet
Transmission Type	Constant mesh 5-speed
Gear Ratio 1st	37/13 (2.846)
Gear Ratio 2nd	37/20 (1.850)
Gear Ratio 3rd	30/21 (1.429)
Gear Ratio 4th	27/23 (1.174)
Gear Ratio 5th	28/27 (1.037)
Ignition System	T.C.I. (digital)
Final Transmission	Chain

Chassis
Overall Length	2170 mm
Overall Width	780 mm
Overall Height	1280 mm
Seat Height	795 mm
Wheelbase	1470 mm
Minimum Ground Clearance	160 mm
Dry Weight	198 kg
Frame Type	Steel, diamond shaped
Caster Angle	25°
Trail	105 mm
Fuel Tank Capacity	20 L
Front Suspension	Telescopic fork 41mm
Rear Suspension	Swinging arm (monocross)
Front Wheel	MT3.00 x 18, Aluminum
Front Wheel Travel	149 mm
Rear Wheel	MT4.00 x 17, Aluminum
Rear Wheel Travel	140 mm
Front Brake	Dual discs, 298 mm diam
Rear Brake	Single disc, 245 mm diam
Front tyre	110/80 ZR18
Rear tyre	150/70 ZR17

External links

True Horsepower Reference table