Bimota Tesi ID 851


Make Model

Bimota Tesi ID 851


1990 - 1991


127 units


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


851cc / 51. 9 cub. in
Bore x Stroke 92 x 64 mm
Compression Ratio 10.4:1
Cooling System Liquid cooled


Weber fuel injection


Analoque CDI
Starting Electric

Max Power

72.9 kW / 103 hp  @ 9500 rpm

Max Torque

83 Nm / 8.75 kgf-m / 61.2 lb-ft.@ 8500 rpm


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
Wheelbase 1410 mm

Front Brakes

2x 320mm discs 2 piston calipers

Rear Brakes

Single 230mm disc 1 piston caliper

Front Tyre


Rear Tyre



Length: 2265 mm / 89.2 in.

Width: 770 mm / 30.3 in.

Height: 1120 mm . 44.1 in.

Dry Weight

188 kg / 414.5 lbs.
Fuel Capacity 16 Litres / 4.2 us gal

Top speed

250 km/h / 155.3 mph

Road Test


Bimota Tesi is a number of motorcycles produced by the Italian manufacturer Bimota . The prototype was developed in 1983 , but you have to wait until 1990 to see the commercialization of the approved version for road use: Thesis 1 / D. Thesis 2 / D, the work of an Italian coach who had made their own (Vyrus 984 C³ 4V), continues the interrupted series in 1994 , followed in 2007 by Tesi 3 / D, with which the project has arrived to the present day.

The production Ducati . The main innovation of the Bimota Tesi is the presence of a front fork equipped with steering wheel hub instead of the classic telescopic fork.

The operating principle of this system is intended to separate the function of "steering" by that of "suspension" (interdependent in the fork) and to drastically reduce the effect of "sinking" of the classic fork braking almost to cancel it and contribute to maintain a better stability of the bike and road holding.

The telescopic fork, which is mounted on the vast majority of the bikes homologated for road use, combines both the function of steering than that of the suspension, so that the action of a irretrievably influences the other. The concept developed by engineer Difazio is to completely separate the guide from the suspension. In this way, undesirable interactions between the two functions disappear.

The setting of the bike does not change during braking as with a traditional fork. That provision also allows you to change the geometry of the bike (wheelbase, caster), though without affecting the dynamic behavior. This is not the first time this technique is used (as it was the motorcycle ELF X and its derivatives), but until now had never left out of the racing circuits. With the Thesis, Bimota transposes it into an approved motorcycle.

The two swing arms are connected by a frame in Omega. The wheel hub is formed by two conical bearings and an axis. Through a series of rods and referrals, it is connected to a steering pin is located on the left side of the motorcycle, bound to the frame. A further transmission rod connects the handlebars [1] .
The frame is reduced to two side plates which embrace the engine and supporting the tank, the handlebars and the rear seat and equipped with pins at the ends, to which are connected the swing arms, with consequent saving in weight.
But this architecture requires the construction of a very large number of components to realize the front suspension, with the corresponding increase in costs. These pieces must be properly sized to withstand the high stresses to which they are subjected during braking. Moreover, the assembly and maintenance of the steering linkage must be made with extreme care, to minimize the play between them, deleterious for the driving precision.

It should also be taken into account that the front fork sharply increases the turning radius, making complicated parking maneuvers , although this disadvantage has been reduced on Thesis 3 / D through the adoption of an arm made of tube trellis, allowing the use of tubes of small section from the smaller footprint without going to the expense of stiffness.