Bimota Tesi ID 906

 

 

 

Make Model

Bimota Tesi ID 904

Year

1991

Production

20 units

Engine

Four stroke, 90°“L”twin cylinder, DOHC, desmodromic 4 valves per cylinder 

Capacity

904 cc / 55.2 cub. in.
Bore x Stroke 92 x 68 mm
Compression Ratio 10.4:1
Cooling System Liquid cooled

Induction

Weber fuel injection

Ignition

Ignition

Electric

Max Power

 84.3 kW/ 113 hp @ 7500 rpm

Max Torque

92 Nm /  9.4 kgf-m / 67.9 lb/ft. @ 7000 rpm

Transmission

6 Speed 
Final Drive Chain
Frame Pair of upside down boomerang shaped plates that envelope the engine on either side. They are made of aluminium alloy and are machined not cast. The engine, unlike the preceding series, has no load bearing functions. At the far ends of the engine are the hinged swing arms, made of anticordal alloy.

Front Suspension

Swinging arm with Marzocchi single shock stepless preload 10-way compression and 25-way preload damping adjustment

Rear Suspension

Marzocchi single shock stepless preload 10-way compression and 25-way preload damping adjustment

Front Brakes

2x 320mm discs 4 piston calipers

Rear Brakes

Single 230mm disc 1 piston caliper

Front Tyre

120/70-17

Rear Tyre

180/55-17

Dry Weight

188 kg / 414.5 lbs

Fuel Capacity

16 Litres / 4.2 US gal.

Consumption  average

7.4 l/100 km / 32 mpg

Top Speed

225.3 km/h/ 140 mp/h

The second version of the Tesi was actually presented only a few weeks after the first. The only modification was engine displacement which was increased from 851 to 904. It was absolutely identical to the 1D 851 and was later to become known as the "SR". This was to cause confusion as the later "SR", which was different in both appearance and chassis.

The Bimota Tesi is one of the most radical, m extraordinary and most interesting superbikes ever built. With the Tesi, the small Italian factory took a giant leap forward in motorcycle design, one that only Yamaha (and to a lesser extent BMW) have dared to follow, although 'specials' builders such as Nico Bakker have produced similar machines in very' small numbers. What Bimota did was put into production a superbike that featured hub-centre steering rather than traditional telescopic front forks.

The problem with conventional telescopic forks is that they flex under braking and cornering, and because they compress under braking, the steering geometry of the bike is altered. In an ideal world the suspension and steering of a motorcycle should be separate and independent to each other. With telescopic forks this isn't possible, no matter how good the forks are, but with hub-centre steering the suspension can be separated from the steering.  So instead of wrapping the motorcycle's engine in a conventional frame and then bolting a pair of forks to the headstock and a rear swingarm to the back, Bimota have wrapped their chassis around the sides of the engine and then bolted a swingarm on at the front and at the back. The rear swingarm pivots in the traditional way and actuates the rear shock, while the front shock is bolted to the left-hand spar of the front swingarm and to the chassis. A complicated system of linkages joins the steering column to the front wheel to allow almost 30 degrees of steering movement. One of the advantages of using a twin-sided front swingarm (as opposed to a single-sided one like the Yamaha GTS 1000) is that it allows two brake discs to be used. And with twin 320mm front discs gripped by four-piston Brembo calipers, the Tesi has one of the best brake set-ups of any superbike.

The engine itself is a modified version of the Ducati 904cc water-cooled eight-valve dcsmo-dromic V-twin engine which uses a development of the Weber-Marelli fuel-injection system to produce a hefty 117bhp. If all this doesn't sound exotic enough, the whole bike is clad in carbon-fibre bodywork and equipped with a pair of Kevlar silencers. The finished result is a bike that scales a featherweight 4071bs dry and which has a whcelbasc more akin to a 400cc machine than a litre bike. On the road the Tcsi is quite unlike anything else. The lack of dive when slowing, and the fact that the suspension continues to work during hard braking, means that the Tesi can be braked later and cornered harder than anything else on the road. The fire-breathing Ducati engine means that top speeds of 160mph are a breeze and that in terms of performance the Tcsi will stay with the very best that Japan has to offer. The down side is that the Tesi is a solo machine, with no accommodation for pillion passengers, and it costs twice as much as a Yamaha GTS 1000. In fact, except for the Honda NR750, the Tesi is the most expensive production bike in the world. But then it is also arguably the best production bike in the world.

Source Super Bikes  by Mac McDiarmid