Technology highlights: Bimota Tesi, Honda NR 750, Norton TT

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Technology highlights: Bimota Tesi, Honda NR 750, Norton TT
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Technology highlights: Bimota Tesi, Honda NR 750, Norton TT

Techno motorcycle

The pace of further development in two-wheelers is getting faster and harder. Real technical innovations such as the Bimota Tesi, Honda NR 750 or Norton TT, on the other hand, are rather rare today.

An almost lethargic-seeming continuity determines the series production of the large two-wheeler manufacturers. New engine concepts, innovative chassis technologies, extraordinary safety devices ?? Nothing. In contrast, the manufacturers sell us the features required by legislative regulations such as injection and regulated catalytic converters as sensational innovations. Wasn’t everything better in the past, richer in ideas? In the retrospective, manufacturers have to be asked this question.
The last really creative phase in motorcycle construction goes back to the early 90s. Even the extremely conservative Japanese ventured out of their constructive reserve at the time. Honda presented a through with the NR 750
and through an extraordinary engine concept; With the GTS 1000, Yamaha realized a visionary front suspension. The small Italian noble forge developed a similar construction
Bimota achieved cult status, while BMW was the first company to achieve success with an alternative to the conventional fork, the Telelever. Norton, in tough survival training in the 90s, made a virtue out of necessity and tailored
around the existing rotary engine a sports motorcycle.
Honda NR 750, Bimota Tesi and
Norton TT ?? three examples of except-
Ordinary concepts, united by a prestigious image, unusually high cost prices (100,000, 65,000 and 30,000 marks) and the sporty focus. But end there
already the similarities of the projects from three different countries.
The Italians concentrated entirely on new designs in the chassis area. As early as 1983 Bimota presented a prototype with wheel hub steering, which engineer Pierluigi Marconi developed over the years until it was ready for series production. In 1991 the time had come. The Tesi 1D not only had the wheel hub steering, but an equally innovative frame concept that nestled around the Ducati 888 engine, which was enlarged to 904 cm3. A double swing arm supports the front wheel against the frame. The wheel sits on its axis inside-
hub of the steering knuckle, the driver
operates the steering via a steering linkage. An extremely complex construction-
tion that at least in the Tesi some
Caused problems. And for plenty
The Italians were upset with the MOTORRAD testers. They had complained about the tendency of the Bimota to pendulum at speeds of over 200 km / h, which in Rimini was tantamount to an offense against majesty.
That has long been history, so a good decade later, MOTORRAD can easily step onto the Bimota Tesi 1D ES from collector Karl Heinz Huwels, which has been in perfect condition. Already
the old feeling returns when you try to sit. The driver has to be very long
make and lies almost horizontally on the Tesi. After just a few meters it seems that the “Edizione Speziale”
absolutely nothing of the straight path
dissuade, it suggests sheer driving stability. The chassis relentlessly passes the slightest bump in the ground to the driver.
A peculiarity that is not due to the wheel hub steering system, but to Gianluca. Exactly, the former test driver Gianluca Galasso, who implemented his very own chassis philosophy without regard to intervertebral discs. His motto: hard makes fast, harder faster. Thanks to his racing ambitions, almost all Bimota had only limited suspension,
so does this Tesi. A shame, because that completely negates one advantage of the wheel hub steering, the sensitive response behavior. Furthermore, this front wheel control is characterized by high system rigidity with low weight and freely selectable brake pitch compensation. The Tesi masters the latter perfectly. When the brakes are applied, the Brembo four-piston calipers decelerate excellently even from today’s point of view, the front only dips even when decelerating hard-
slightly a. An advantage that many racing drivers used for brutal braking maneuvers.
But when the Ducati-Desmoquattro pounds on the highway and the Tesi accelerates to over 200 km / h,
it is present again, stirring around
the vertical axis. However, it does
is also not a sys-
Temporary problem, rather it is
To look for horsefoot in the structural design that makes a correct attitude to walking the tightrope. Just like the whole motorcycle balances on the ridge between genius and madness.
Unfortunately, apart from the Telelever, the considerations have become too old-
native suspension has not yet been implemented. Why, the Ent-
winder of the Ducati Desmosedici, Fillippo Preziosi, to the point. His answer to the question why he uses a telescopic fork in the MotoGP project: »You
is certainly the worst kind of pros-
Derradfuhrung, but the most developed and therefore currently the simplest solution. «Introducing the circumferential and cornering forces directly from the tire contact point into the frame sounds logical and consistent, but is obviously not really present in the minds of the designers. The lack of success of the Yamaha GTS 1000, which did not suffer from the stub axle steering but from other problems, also served as a good argument, no further energies ?? and thus money ?? in alternatives to
To plug the telescopic fork.
The high financial outlay did not seem to play a role in the Honda oval piston engine. But how came
it at all about this development? Honda President Kawashima announced his return to Grand Prix racing in 1977 and wanted to challenge the two-stroke engine with a four-stroke engine. Since that can only be done with extreme speeds-
leagues, but the number of cylinders in the 500 class was limited to four, a conventional design was out of the question. Logical consequence: the round pistons had to be wider. This is how the oval piston engine came about, in which
four in each of the four cylinders
Inlet and outlet valves stand in a row and which realizes the free inlet cross-sections of an eight-cylinder.
However, the insane construction effort should not be worth it. When it made its debut at the 1979 Silverstone Grand Prix, the NR 500 was inferior to the competition. After four unsuccessful years, Honda stopped the project. But lo and behold, in 1987 the oval piston engine celebrated a happy start at the long-distance classic, the 24 Hours of Le Mans, even if a connecting rod screw permanently destroyed the engine after six hours. In the same year Honda announced the serial production of a motorcycle with an oval piston engine. With Donner und Gloria, the Japanese presented the NR 750 at the Tokyo Motor Show in 1989. In the spotlight was a noble piece of high-tech with injection, single-sided swing arm and carbon fiber monocoque and anticipated a great piece of the future with design elements such as the silencer in the rear or the electronic cockpit.
As seldom as the NR, which has only been built 1000 times, is to be found on the road
it seldom came into the hands of journalists. This time MOTORRAD receives an NR from Emil Schwarz, the specialist at
Precision parts for motorcycle chassis. The denied having problems at the
Injection system, however, the regular service and can only complete the photo trips. So we have to share the impressions of our colleagues Koch and Pfeiffer
at the beginning of the 90s. »Despite the small stroke of 42 milli-
meters pushes the NR in the loose
Roll on vigorously. The dull sound is confusingly similar to that of the RC 30 up to 12000 rpm. From 8000 full power, which increases evenly to the red area at 15000 rpm. The feeling for the actual 125 hp is blurred under the broad usable power band and the even power curve, ”says Werner Koch. »When you turn the throttle, the V4 cheers up like lightning, a 500 two-stroke can hardly do better. The development of the NR can only inadequately be described with the power band. From 2000 to 15000 rpm it offers power without a break, the higher it turns, the more aggressive the sound, «is the enthusiastic report by Michael Pfeiffer.
The Norton TT is also going through
their unusual engine concept, the rotary engine, attracted attention. As early as 1969, Norton engineer David Garsfield should have the potential of a rotation-
piston engine and developed a twin disc engine ?? until the survival of the Norton-Triumph-Villiers group stopped the project. Only under new management did the Wankel go on patrol as “Interpol” with the English police in 1983, and in 1988 as “Classic” also in community service. In the 1000 cm3 class held in England, the Norton won sporting laurels and even won the prestigious Tourist Trophy with Steve Hislop.
And now we can experience it again, the TT from Norton Germany boss Joe Seiffert, as we did before eleven
Years in the paddock of the Nurburgring. At that time, the Norton compressed the already dense Eifel when it took off-
fog at a range of two meters and enriched it aromatically with Castrol haze. Exactly the same process, all this time-
in the editorial underground car park. Thick oil mist initially calls the smoke-
reporter, then the caretaker on the scene. The TT can only prove its qualities in the wild. As if a massless sound generator and not a combustion engine with rotating masses provided propulsion, the Norton pushes forward evenly.
Solid mechanical engineering mediates Elek-
tromotor feeling. However, quite and
not at all with its acoustic closure-
restraint. The rotary engine plays the emcee among motorcycle engines. He imitates them all, the distinctive, the really important sound machines. The muffled, throaty bass of a Triumph Daytona, the typical howling of a Honda CBX to the bright singing of a Kawasaki KH 250 in the red area. The best thing about it: the driver is a DJ, and can determine the beat, pitch and volume with the throttle hand on the right rotary control. Dear developers, forget everything you’ve learned about sound engineering, check out the Norton. But be careful, you will throw your entire equipment overboard and start all over again. A special kind of sound experience that makes you forget the weaknesses such as the annoying constant jerk or the delayed throttle response.
A special experience that everyone
three motorcycles offer in very different ways, be it through the technically, visually or acoustically extraordinary. And thus perfect tools to strengthen the image of a brand, even if only a fraction of motorcyclists can ever experience the fascination of these exotic species for themselves. But monument preservation alone, no matter how intense it may be, cannot create a nimbus for all time
preserve. That’s why clever strategists throughout history always remembered each other with new heroic deeds
Gcalled. A tactic with which world-renowned companies would be well served today. The small manufacturers in particular have often shown more courage to make constructive gaps, but have usually had to pay dearly because of too short a breath. Even a Honda RC 211 V for the road could set an example.

Technical data: Bimota Tesi 1D ES

EngineWater-cooled two-cylinder four-stroke 90-degree V-engine, crankshaft transverse, two overhead, toothed belt-driven camshafts, four desmodromic valves per cylinder, wet sump lubrication, electronic intake manifold injection, Ø 54 mm. Bore x stroke 92.0 x 68.0 mm displacement 904 cm3 Compression ratio 11.6: 1 Nominal output 83 kW (113 HP) at 8500 rpm Max. Torque 92 Nm (9.4 kpm) at 7000 rpm power transmission Hydraulically operated multi-disc dry clutch, six-speed gearbox, O-ring chain. Chassis frame made of aluminum plates with tubular steel subframe, trailing arm with wheel hub steering, central spring strut with lever system, adjustable spring base, tension and Compression damping, two-arm swing arm made of aluminum profiles, central spring strut with lever system, adjustable spring base, rebound and compression damping, double disc brake at the front, floating brake discs, Ø 320 mm, four-piston calipers, disc brake at the rear, Ø 230 mm, two-piston caliper. Cast aluminum wheels 3.50 x 17; 5.50 x 17 tires 120/70 ZR 17; 180/55 ZR 17 Chassis data, steering head angle variable, caster 83 mm, wheelbase 1410 mm, spring travel f / h 80/120 mm. Dimensions and weights Seat height * 775 mm, weight with a full tank * 222 kg, tank capacity 16 liters. Price 64,800 marks

Technical data: Honda NR 750

Water-cooled four-cylinder, four-stroke, 90-degree, V-oval piston engine, transverse crankshaft, two overhead, spur gear-driven camshafts, eight valves per cylinder, bucket tappets, wet sump lubrication, electronic intake manifold injection, Ø 30 mm. Bore x stroke 101.3 / 50.6 x 42.0 mm Displacement 747.3 cm3 Compression ratio 11.7: 1 Rated output 92 kW (125 PS) at 14,000 rpm Max. Torque 71 Nm (7.0 kpm) at 11500 rpm Power transmission Hydraulically operated multi-disc oil bath clutch, six-speed gearbox, O-ring chain. Chassis Bridge frame made of aluminum profiles, upside-down fork, guide tube diameter 45 mm, adjustable spring base, rebound and compression damping, single-sided swing arm Cast aluminum, central spring strut with lever system, adjustable spring base, rebound and compression damping, double disc brake at the front, floating brake discs, Ø 310 mm, four-piston calipers, disc brake at the rear, Ø 220 mm, double-piston caliper. Cast magnesium wheels 3.50 x 16; 5.50 x 17 tires 130/70 ZR 16; 180/55 ZR 17 Chassis data Steering head angle 65.5 degrees, caster 88 mm, wheelbase 1435 mm, spring travel f / h 120/120 mm. Dimensions and weights Seat height * 785 mm, weight with a full tank * 244 kg, tank capacity 17 liters. Price 100,000 marks

Technical data: Norton TT

EngineWater-cooled twin-disc Wankel engine, fresh oil lubrication with oil pump, constant pressure carburetor, Ø 38 mm, transistor ignition. Chamber volume 2 x 294 cm3 Displacement 588 cm3 Compression ratio 9.0: 1 Nominal output 66 kW (90 HP) at 9500 rpmMax. Torque 78 Nm (7.9 kpm) at 7500 rpm Power transmission Hydraulically operated multi-disc oil bath clutch, five-speed gearbox, O-ring chain. Chassis Bridge frame made of aluminum profiles, upside-down fork, guide tube diameter 40 mm, adjustable rebound and compression damping, two-arm swing arm made of Alupro filen, central spring strut with lever system, adjustable spring base, rebound and compression damping, double disc brake at the front, floating brake discs, Ø 320 mm, four-piston calipers, disc brake at the rear, Ø 230 mm, four-piston caliper. Cast aluminum wheels 3.50 x 17; 5.50 x 17 tires 120/70 ZR 17; 170/55 ZR 17 Chassis data Steering head angle 65 degrees, caster 99 mm, wheelbase 1440 mm, spring travel f / r 110/143 mm. Dimensions and weights Seat height * 750 mm, weight with a full tank * 234 kg, tank capacity 24 liters. Price 29,700 marks

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