Bimota SB5

 

 

 

 

Make Model

Bimota SB5

Year

1985

Production

158 units

Engine

Four stroke, transverse four cylinders, DOHC, 4 valves per cylinder

Capacity

1135 cc / 69.3 cub. in.
Bore x Stroke 74 x 66 mm
Compression Ratio 9.7:1
Cooling Air / oil

Induction

4x 36mm Mikuni carbs

Ignition

-

Starting

Electric

Max Power

85.8 kW / 115 hp @  8500 rpm  ( 88.7 kW / 119 hp @ 8500 rpm)

Max Torque

104 Nm / 10.6 kg-m / 76.7 lb/ft. @ 6500 rpm

Transmission

5 Speed

Final Drive

Chain
Frame Chrome molybdenum steel double closed cradle

Front Suspension

Italia 40 mm front fork

Rear Suspension

single Central shock absorber.

Front Brakes

2x 280mm discs

Rear Brakes

Single 280mm disc

Wet-Weight

 233 kg / 513.7 lbs.

Top Speed

248 km/h / 154.1 mph

In twenty years or so when the history of motorcycling over the past decade comes to be written, classic bikers of the 21st Century will be able to take a dispassionate look at what we may call the "Bimota Syndrome". Analysis, take one bog standard megalump of Japanese origin, devise your own exhaust system, and lay the result on a table. Take ample supplies of high tensile chrome Moly Columbus tube, ditto sheets of ultra light and very strong Avional and Ergal aircraft alloy. Mill, drill, stamp, weld the said materials around your power unit, then hang the very best in aftermarket components and accessories. Such as Forcelli Italia forks, Golden Brembo calipers, floating discs, De Carbon suspension units etc. Not happy with the steels available? Make your own in aircraft alloy with four sections bonded and riveted together - 16 inches front & rear.

Then put the whole thing together within a seductive, alluring but voluptuous set of bodywork with superb graphics and a high quality paintjob, multiply the price you first thought of by two. Just sit back and wait for the orders to flow in as punters would not be seen dead on anything else but the best, Because make no mistake, when it comes to riding road bikes, The best has been Bimota. Of course in the same way as this description of design and construction of these beautifully made products of the Rimini based company is hopelessly facile, so there is much more to explaining the Bimota Syndrome than just simply saying that people buy them because they are scare and expensive. Perhaps we may have to wait for our 21st Century man to take a significantly objective look at the "why's" and "wherefores" to give the answer, but there is no disputing that not only have Bimota's products always been superbly made, they also set new standards of road holding and handling at the end of the 70's and early 80's for bikes powered by oriental multi cylinder engines.

And there is no doubt that for every Bimota customer over the years who has been a pavement poser, there has been another riding the bike hard enough to explore the additional potential it offers. Not for anything is Germany easily Bimota's largest market, with its no limit Autobahn's and the twisting mountain roads. Yet their second is Japan with its crucifying speed restrictions and predominantly image orientated Motorcyclist population. All of which makes the fact that it has taken Bimota almost ten years to build their first model capable of use as either a single or dual seat machine rather surprising. Not being a two-wheeled boulevardier myself, I do not really know what makes these people tick, but I'd have thought it was desirable to take someone along to show off to in case you cannot find an audience anywhere else? But at the same time and more seriously, there is no reason that riding a sports bike should be a solitary experience most manufacturers deem it ought, while at the same time I don't honestly fancy having someone on a pillion while I exercise the 150 mph potential of a one litre engine or bigger. What is more sensible therefore than to build a bike capable of ready conversion from one to the other without adversely affecting either the performance or handling - or, lets face it the looks?

The Bimota SB5 is that bike. Like the single seat SB4 from which it is derived (a slightly longer wheelbase, altered suspension curve and altered weight distribution, together with the "decapotabile" rear seat squab are the only real differences between the two). The SB5 is powered by a standard 1135cc DOHC Suzuki engine, supplied directly to Bimota (together with the instrument cluster) by the Japanese manufacturer in a ground breaking agreement that Bimota no longer have to buy complete bikes and hope enough people lunch their GSX1100ES's to enable them to sell off the unwanted stock of cycle parts. Nevertheless, an increasing number of local Bimota Concessionaires, such as British distributor Dick Linton of FCL in Cranleigh, are buying frame kits and building complete bikes out of locally available engines in order to defray slightly the, by any standards, alarmingly high price, figure at least £9700 for the fastest dual seat road bike in the world, and now you know why it is called the "Ferrari of Motorcycles". Who said the best ever came cheap? I've ridden half a dozen different Bimota's down the years (yes I know this job is hell isn't it?) but while I have always admired their execution, I must honestly admit that even if they were half the price I have never really fancied owning one, even though I have always liked big bikes and with my lanky build find it hard to stay comfortable for a long ride on something like a Ducati 600 TT2 replica. Actually that part of the problem with Bimota's in general for me, they are very low built and the 16 inch front and rear wheels means a low seat height which is compensated for me by jacking the footrests up a bit higher than I like to give sufficient ground clearance. I am not that big a fan of 16-inch wheels anyway, even if the Bimota has not suffered any of the high-speed stability problems latterly experienced by the German testers with bikes fitted with two 16-inch rims. I do not like the way such machines sit up on you under braking and try to under steer straight ahead, especially if you have the anti dive torques up, because the degree of rider effort you have to exert to shove down on the bar in order to make it go where you intended completely negates the faster steering and more positive directional control you get with a smaller rim. And before you remind me that many (though by no means all) current GP bikes have 16 inch wheels, let me point out that you need a lot less effort to tell a 90-120 kgs racer where to go than a fully equipped road bike scaling twice as much or more. Anyway back to Bimota's. I think the real reason why they have never really enthralled me is a paradoxical one, they are just too well made. I feel subconsciously I should be looking at them rather than riding them, admiring all the little bits and bobs that original designer Massimo Tamburini and his successor Federico Martini, stick on the bikes to make them work.

 The chassis itself is a work of art, on the SB5 you have the design first pioneered by Tamburini on the Honda powered HB3 five years ago, now copied (but not emulated) by Yamaha on their FJ1100, with the frame tubes triangulated around and in front of the steering head to form an immensely rigid structure, and the rear engine cradle formed by two Avional plates bonded and bolted to the top and bottom frame tubes.

The well braced rear steel swing arm operates the rising rate de Carbon rear suspension via a series of beautifully made rods and rocker arms, rose joint and spherical bearings all abound - and look at the little touches like the eccentrically mounted upper stop for the brake pedal - itself a masterpiece of the alloy craftsman's trade. Riding such an exquisite creation has always been for me the two-wheeled equivalent of siting in an expensive restaurant and thinking how I would rather be tucking into a glass of beer, just because I know I would feel more comfortable. Maybe if I could afford to buy a Bimota myself I would not feel this way, and I suspect most people who can and do probably think nothing of marching into a three star Michelin noshery in their leathers (Bimota ones, of course) and ordering up. Ah well - how the other half-lives. At least for a day on my last visit to the factory I was able to borrow the factory SB5 test hack and spend a day dreaming on it. It was a case of second time around in a way, because I had already ridden the SB5 briefly at the Bimota test day, last November when I tried to tame the Tesi. Bimota had had to take some stick from Pirelli after that because of my disparaging comments on the radial tyres fitted to the bike. So they were keen for me to try again for a longer stint. Oh well I suppose if you insist….To be honest I felt more at home on the bike than on any previous Bimota, and looking back on it afterwards, I think there are a number of reasons. First of all yes Mr. Pirelli I think you tyres are OK on a warm spring day on dry roads, but I remain to be convinced about how they perform in the wet, cold weather and their wear rate.

Though the latter not first hand I admit. I have seen a Bimota go through its rear Pirelli down to les than the British legal limit in a shocking short time. And they do seem to wiggle a little in a straight line. I still want to know what advantages these tyres have over the Michelins Bimota used to use before, or indeed Pirelli's own excellent non-radial Phantoms. I thought it was only the Japanese that if it was new it was better? Anyhow, back to the bike itself. Maybe it was because it was well used - and certainly had a tired engine, which sounded a bit rattley, and in need of a tune up - but during the short time I spent on the Sb5 I got to feel very comfortable with it. Sort of kike a comfy old boot that slips on and off easily. I decided to forgo my usual blast down the autostrada to Pesaro and beyond in favour of a slower ride through the hills and valleys of San Marino - in which pocket sized country, incidentally resides the best looking Police person in the world whom I stopped to ask directions,

 

 but that is another story. It was a nice day, spring was in the air, there was hardly any traffic - yes I know it is a 10,000 lira automatic fine for crossing the white line even in San Marino, but I do not think they have any traffic cops there and certainly not the kind that hide up the side roads. Flipping the bike easily from one side to the other, up and down the winding roads, squirting the big Suzuki "diesel" between corners in third gear with even this well used engine offering gobs of torque and making gear selection almost redundant, squeezing the outstanding Brembo brakes hard for an effortless but instant stop when a hay laden cart pulled out in front of me, or a blind corner revealed a snail like tractor creeping along in the opposite direction in the middle of the road - it makes a nonsense of the road signs . 50 Kph on a winding road on a Bimota? You must be joking add a one in front and you still will not get into any trouble - well probably not anyhow… Part of the bikes effortless behavior over less than ideal road surfaces with frequent turns can be attributed to the experimental Marzocchi M1 forks fitted to it for evaluation, which have in built hydraulic anti dive (adjustable by means of a knob in front of the lower fork leg) and air damping. They seemed to have really good suspension response, did not freeze under heavy braking, and also did not make the bike sit up in corners as much as I remember with the Forcelli's, even if they did not have any anti dive at all. Strange.

Anyway Bimota plan to fit these new generation Marzocchi's to the DB1 Ducati engined model, and introduce them on the SB5 as well once development is complete in the autumn. However, that presupposes an extended life for the SB5, and I could not help wondering whether the tide has not swung away from this type of bike. Bimota Boss Guiseppe Morri plans to build 300 such machines this year, with the demand for the dual seat SB5 such that the SB4 has effectively been discontinued. But now that the Japanese have started producing what amounts to an assembly line Bimota at half the price, the Italian companies traditional market of well heeled connoisseurs is being seriously eroded. Add to that the latter day emphasis on 750 sports machines and suddenly the fact that Bimota have only ever produce one bike of less than 900cc (the neat little GPz550 powered KB2) starts to look a bit of a liability.

No wonder Morri and Martini are working on the DB1 and more importantly the FZ750 powered machine (the YB4?). Somehow I think that will be my kind of Bimota - well you can always dream can't you - now that my ride on the Sb5 tester has cured my fear of falling for the seductive charms of the Latin lovely. It will be interesting to see how Martini copes with the design challenge of those down draft carbs, especially given the SB5's safety orientated steel tank shrouded by the fibreglass seat / tank unit. But I am sure it will look sensational. However if you want to share your Bimota biking you will still have to go for the SB5, which for some time will continue as the only dual seat option from Rimini. Just make sure she holds on tight when you crank into that fast sweeper at 200 Kph plus

Source Alan Cathcart, Superbike August 1985