From our Old Bike Archives – Issue 84 – first published in 2019.
Story: Nick Varta • Photos: Independent Observations.
Standardisation is a concept that sits uneasily with those of the fertile and inquiring mind. It was the attraction of Ducati’s V-twin in a sea of UJM (Universal Japanese Motorcycle) four cylinder machines that made the Italian machine so attractive to people who wanted something a little different. But even there, the standardisation of the modern motorcycle chassis – swinging arm rear suspension, telescopic, hydraulic front fork – was common virtually across the range.
For ages, the telescopic fork had been viewed with distaste by engineers, citing numerous in-built shortcomings. The ‘tele’s’ predecessor, the girder fork in all its incarnations – pressed steel, tubular steel, friction damped, hydraulic damped et al – certainly had shortcomings as well, but they were relatively inexpensive to produce, quite strong, and easily repaired or refurbished. The ‘tele’ on the other hand, required precision machining or grinding of the fork tubes, matched to precision casting and/or machining for the sliders, and suffered the problem of stick-slip friction (or ‘stiction’) under heavy braking or side loads (especially when used on sidecar outfits). There were other issues concerned with geometric forces during the actual steering process that also rendered the concept less than 100% satisfactory. But there was no denying that the telescopic fork, especially the Norton Roadholder (itself modelled on the BMW design) was pretty good – so good in fact it changed little, and had few challengers, for several decades.
Those challengers eventually came mainly from Italy – Ceriani, Marzocchi, Focelli – and excellent they were too, albeit refinements on a well established theme. But one small Italian company, based at Rimini on the Adriatic coast and away from the major centre of Milan, was utterly convinced of the benefits of what had long been termed ‘hub steering’ or ‘hub-centre steering’.
Once again, the concept was far from new – look at such ancient creations as the 1911 Militaire 1300cc four-cylinder, complete with hub steering, or the adventurous Ner-a-car, and the numerous creations of Jack Difazio who made his first hub-steerer in 1956 using bits from a Reliant 3-wheeler, a Ford Prefect brake drum and various rods and sods collected from wherever they were available. However Bimota saw all these attempts as somewhat crude and unsuitable for series production. By 1990, after a series of prototypes dating back to 1983, they were ready to take the plunge, and it was a big plunge, to put their concept of a ‘forkless’ motorcycle into production.
Please form an orderly queue
The Bimota Tesi 1D (‘tesi’ approximately equating to ‘thesis’ in English) was conceived from the outset to be an exotic, eccentric and expensive motorcycle aimed at a discerning (and small) market. At around US$40,000 the market was certainly going to be small, but it equally certainly existed. Tesi was essentially a collection of the finest Italian components and engineering, centred around an 851cc, fuel-injected Ducati v-twin engine. The chassis no longer required a conventional steering head, although from the rider’s point of view, a top crown was there to support the handlebars, which were mounted on a pair of stubby tubes, clip-on style, below the top crown. The actual steering was achieved via a series of rods and linkages that ran down through the vee of the engine, out through the milled-from-solid right side chassis plate and along the right side of the swinging arm supporting the front wheel. The wheel itself held a large diameter, ultra thin ball bearing, supporting a trunnion shaft, upon which the wheel rotated. In the centre of the trunnion shaft sat a kingpin, which allowed the shaft to be rotated via the external rods for steering. The shaft and kingpin could also be rotated slightly to adjust the rake and trail of the front suspension via screw adjusters on the ends of the torque rods. Many road tests commented on, rather than criticised, the heavy steering, which was not surprising considering any movement of the steering put four spherical bearings and six roller-type bearings into play.
The front brake disc was bolted to the wheel in conventional manner. With the need for the front wheel to move within the swinging arm, the rear of this had to be wider than the front. Like all Ducati vee twins, the engine was positioned as far forward as possible without contacting the front tyre, and held in place by the very handsome alloy plates on each side. These plates provided the attachment points for the front and rear suspension. At the front, a single fully adjustable Marzocchi gas shock took care of things, mounted horizontally above the left side alloy frame plate. At the rear, the single Marzocchi gas shock sat vertically, operated via a lever from the swinging arm.
The fuel tank, moulded in plastic, sat above a trellis structure, with an extension of the tube structure behind this to support the seat and provide the top mount for the rear shock absorber. Another plastic moulding, the airbox, sat inside the forward tubular section, connecting the injector trumpets. The exhaust system was also unconventional, with twin pipes exiting each cylinder head, then diverging so that one from the front cylinder and one from the rear went to a single muffler on each side.
Trend-setting for the day, an LCD instrument panel contained a digital speedometer, odometer and trip meter, tachometer, with readouts for water/coolant temperature, fuel level, and lights to indicate oil pressure, indicators, neutral, low fuel, and high beam. The whole machine was clothed in swooping bodywork consisting of a nose panel, and a combined tank shroud, seat/tail and side covers. The front wheel was shrouded in a sporting colour-matched mudguard, while the rear tyre received a GP-style ‘hugger’ in black plastic. One of the few non-Italian parts was the large capacity, curved radiator which came from KTM.
It’s fair to say that the Tesi’s handling and braking characteristics left many testers somewhat nonplussed. Because there was non (or little) of the telescopic fork’s inherent diving under brakes, the front suspension travel was only 80mm, or about half normal. Squeezing the front brake during cornering produced virtually no movement, which meant the rider could adopt a more neutral position on the bike. Although producing a more precise ride, ‘harsh’ was the word most often used to describe the suspension, which over rough roads could be somewhat uncomfortable. Without the pitching in the front end, harder and more stable braking could be achieved, but all of this was foreign to many, and took quite a bit of getting used to. Not to say this was a bad thing, just different, so the ‘forkless’ look, and the riding experience, matched each other perfectly.
The Resurrection
The fate of the Tesi 1D, and other motorcycles in the Bimota range, was effectively sealed when the company filed for bankruptcy in 2000 – a legacy of the ill-fated V Due two stroke and the costs of competing on the World Superbike stage. In 2003, under new ownership, the brand returned, and with it, a heavily revised Tesi, named the 2D, which appeared in 2004. This lasted just over two years, with an asking price of around US$60,000 before the 3D appeared; effectively a completely new take on the original concept. Gone was the bodywork, revealing the skeletal framework in full, as well as the intricacies of the front end and its plethora of rods and levers, although the number of these had been reduced and no longer passed through the frame. Steering lock, heavily criticised in the past, was increased from 17º to 21º – a blessing around town. The front shock was changed in specification, location and movement, being now of the pull-piston design, moving to the right side of the engine under the crankcase. All this addressed most of the concerns of the 1D: the ride was now more comfortable, the steering lighter and more predictable, and suspension action more flexible.
Although the basic look remained, the chassis components were in fact all new, with the rear shock moved from its previous vertical position to an angle of around 45º. Both the front and rear swinging arms were now steel tube trellis design, rather than the previous alloy components. What bodywork that remained was now mainly in raw carbon fibre, although a red and white painted version was also listed. Gone was the futuristic speed display box; replaced by a conventional looking circular instrument with an inlaid LCD display. Power for the 3D came from a 1072cc v-twin engine sourced from the Ducati Multistrada.
Moving right along
If things weren’t rocky enough for Bimota, its Australian distributor Stoney Creek Power Sports shut its doors the day after the Sydney Motorcycle Expo in November 2008. The new Tesi 3D had been featured on the company’s stand at the Expo, as well as the Melbourne Show the previous month. SCPS claimed to have received many enquiries for the new machine, although no pricing had been announced. After a lengthy hiatus period, the Australian distributorship was taken over by Urban Moto Imports, which as late as 2018 still listed two Tesi 3D models, the EVO at AUD$50,890 and the Naked at $55,990. Given that 30 years had passed since the 1D went on sale at US$40,000, those prices would seem to be a bargain.
The Tesi 3D remained in very limited production until the curtain finally came down on Bimota in 2017. Since 2013, the company has been owned by Swiss investors Swiss Marco Chiancianesi and Daniele Longoni, and following the closure of the Rimini factory, the remaining inventory of parts was shipped to Switzerland where a handful of Tesi 3Ds were assembled. Bimota Classic Parts Shop, run by Paolo Girotti, has continued to supply a hungry market with parts for most Bimota models, including the three Tesi versions.
However in October 2019 came the news, long rumoured, that the Swiss investors had concluded a deal to sell Bimota to Kawasaki. Just where the brand will be relocated is not yet known, but it is conceivable that it could return to Rimini. The news means there could yet be life in the Tesi concept.
Despite its ignominious existence, the Tesi remains the most significant attempt to produce a hub-steering motorcycle for the public. Yamaha had a similar tilt at the concept with the GTS1000 but gave up after barely two years, so although hailed as the front end of the future, the hub-steering design is unlikely to replace the telescopic fork any time soon!
A local lovely
Before his untimely passing in 2013, Sydney-based Steve Thompson was a serious motorcycle collector and restorer, notably of Suzuki GT750s, but he was also taken with the new Tesi 3D, and ordered one in 2011. Sadly, he had little time to enjoy it before his health deteriorated, and the motorcycle was subsequently sold to Rob Beard of Melbourne.
“I was looking for an opportunity to add a truly unique bike to my small, unusual collection and was excited to find an amazing example of the Bimota way out in the west of Sydney. The bike was equipped with black wheels when it was delivered which it seems was incorrect. The dealer honoured the original contract and supplied gold wheels in addition to the black. Really quite amazing in this day and age!
The attention the bike receives is quite amazing! Registering it at the Vicroads in Heatherton took a lot longer than normal due to the interest it caused with staff and customers. When riding the bike you limit the number of stops you make and when you do stop you move away from it to avoid a plethora of questions. Due to space limitations, the bike was parked outside my office at work and was the introductory subject with all meetings. There was one observation where it was suggested that it looked like a ‘Transformer taking a dump’! It was at this point that I moved it into the safety of the HR storeroom.
While it was residing in the HR Room the business hosted a delegation of senior representatives of SCM Group – an Italian company that is arguably the world’s largest company supplying specialised hi-tech woodworking machinery. Amongst the visitors was Andrea Aureli, the International SCM Group’s CEO. During a discussion on Italian design flair and passion relating to all manner of machinery one of the visitors became aware of the Tesi in the HR room, he called Andrea saying you must see this. Upon seeing the Tesi he stated that he studied the front end technology when completing his engineering degree! In fact, his father, one of the owners of SCM, had bought Bimota for about 4 years and had never made a dollar from the purchase!
As an average rider, I would say from my perspective that it isn’t a life-changing experience when I ride it but is an incredibly enjoyable bike to ride, comfortable, with heaps of power and impeccable handling manners over all types of roads in all weather conditions (yes it gets ridden in the rain!)”
Specifications: 1991 Bimota Tesi 1D
Engine: Ducati 90º v-twin, four valves per cylinder, belt-driven desmodromic valve operation, liquid cooled.
Bore x stroke: 92.0mm x 64.0mm
Capacity: 851cc
Compression ratio: 11.0:1
Intake: Weber electronic fuel injection, 2 x 50mm throttle bodies.
Exhaust system: 4 into 2
Ignition: CDI
Transmission: 6-speed, dry clutch
Primary drive: Straight cut gears.
Chassis: Milled aluminium plate frame with tubular steel subframes. Box section aluminium swinging arms.
Suspension: Front: Hub-centre steering with single gas shock 80mm travel.
Rear: Swinging arm with single gas shock.
Tyres: Front: 12/70 x 17 Rear: 180/55 x 17
Wheelbase: 1410mm
Brakes: Front: Dual discs with four-piston calipers
Rear: Single disc with twin piston caliper.
Fuel capacity: 16 litres
Weight (wet): 214kg
Price (1991): US$40,000
