Remembering Bimota: The SB2

Reported as fact late summer 2017, the news of Bimota’s shutdown wasn’t exactly a surprise, but reading it was disappointing nonetheless. Remembered best for its horse jockey ergonomics and mechanized wizardry, Bruno DePrato’s report published by Cycle World online (see link below) chronicles the demise of what was once Italy’s brightest two-wheel star. Bimota took the art of special frame building to new heights in both chassis technology and commercial profit. More of former, unfortunately, than the latter, but no specialty firm accomplished more. Mainly using popular and proven inline fours from Japan’s big four and home market Desmo twins, poor sales might not have been the only reason behind Bimota’s Italian exit. Tales of financial ills were common, but that’s the environment of the special frame fabricator. Even after repeated re-launchings hope endured, but when the Rimini works were broken down Bimota truly seemed a lost cause. Some were comforted when Kawasaki (Tesi H2) assumed all rights from Switzerland’s Daniele Longoni and Marco Chiancianesi, yet Bimota as it was, no longer exists.   

Reading DePrato’s take on these 2017 events will be time well spent, but my personal focus worked to pinpoint the precise moment Bimota went from technological tour de force to boutique bunny. I’ve figured the bloom began to wither sometime in the late 1980s, which is also the approximate time Tamburini left the company. Both Suzuki’s radical GSX-R and the Honda V-Four played a role, cutting into Bimota’s exclusive territory for (many) thousands less. Continuing advancement by its mainstream competitors caused Bimota to add more glitter to the jewelry, making the investment towards the Vdue two-stroke a strong move in retrospect. Sadly, instead of restoring Bimota’s performance standing, backlash from the failed concept forced Bimota into bankruptcy. Picked up by willing investors, by 2005 reputation alone was good enough for Bimota to attract top design talent – some even trained by Tamburini himself. Focused again to regain its fame the program of using proprietary engines returned, but mainstream excellence meant even the standout DB5 could not justify its extra cost. Scarcity had become the enemy.

It’s rumored the start-up was a hobby. As Japan’s multis dominated the mid-70s market, Bimota grew out of an air conditioning and heating business that mixed the considerable talent of its founders: Bianchi, Morri and Tamburini. Early in the game racing projects dominated the work, but time was found to produce a street kit using the Honda four. Some attention was paid to the HB1 but national acclaim (and funding) came after providing frames for Johnny Cecotto (Yamaha) and GP ace Walter Villa (Aermacchi/Harley-Davidson). Both resulted in world championships. The work designing Villa’s machine for the 1976 season coincided nicely with the in-house development of the Bimota-Suzuki; the company’s first mass produced product. Tamburini’s parting was not without dispute, but as the engineering lifeblood his mastery post-Bimota continued by establishing new performance levels at Cagiva with the Ducati 916 and MV F4. Each optimized the engineer’s established design fundamentals.

Tamburini didn’t invent the perimeter frame, but the concept figured heavily in the designer’s belief that the shortest, strongest possible load path between steering stem and swingarm pivot is best. As reported by Cycle in a test published September 1978, the SB2’s 54.7” wheelbase is over four-inches shorter and two-inches lower than the donor GS750, yet carries the engine 1” higher in the frame. New for 1976, Suzuki’s 748cc DOHC four attaches to the CoMo structure front and rear, thus used as a stressed member. Custom Ergal clamps hold 36mm Ceriani forks, a De Carbon strut fits the SB2’s monoshock, and Brembo rotors on magnesium wheels. At 472-lb, the SB2 is sixty-pounds lighter than the GS750 too.

According to Bimota literature, the SB2 was available in three versions: 1) As a do-it-yourself rolling chassis, less engine and electrics 2) Fully assembled from the Bimota factory in Italy, including the DOHC Suzuki four 3) Fully assembled from the factory, plus a full Yoshimura performance kit that took the cammy inline multi to 810cc. No answer was given to my question of how many blue/white versions were made, but regardless of color the Bimota SB2 was simply unlike anything else available in 1977. High end specials from Rickman and Harris (these commonly using Honda, Kawasaki, Suzuki…even Laverda three-cylinder engines)  which also competed with the open class Euro roadsters for buyers attention. Each making a history of its own, the Bimota is the closest special frame motorcycle to reach mainstream fame. 

Reading through the Cycle magazine road test, editor Cook Neilson and staff went from skeptical to spellbound in one-half a paragraph. Compacted to the point where the engine’s decorative chrome cam covers were removed for clearance, the SB2’s overall dimensions were a big topic, as were Tamburini’s special chassis features. Well braced everywhere, the SB2’s steering tube is set at 24-degrees but offset clamps add an additional 4-degrees of rake at the forks. Held by set screws, concentric discs live in the center of the trees, offering two different positions to adjust trail. More? The SB2’s bottom most triple tree also serves as a hydraulic splitter for the front brakes, but Tamburini wasn’t done. The monoshock pivots on roller-bearings inside riggers welded outboard of the frame; over the gearbox sprocket. The benefit? Constant tension to a chain working independently of the suspensions. It’s been said the styled rear indicators were a failed attempt at an under seat exhaust system.   

Impeccably finished and with artfully machined billet, the chassis is covered by an aluminum-reinforced fiberglass body secured to a lightweight sub frame with rubber hooks on each side. “Nothing we’ve ridden, except Suzuki’s RG500 Gran Prix bike, can touch it” wrote Neilson and his editors, who also described riding the SB2 in normal traffic and highway travel as “painful.” “Its cornering clearance and the strength of its frame all work together to provide handling, response and stability that’s beyond our critical expertise.” In the end, the SB2’s narrow focus simply could not allow it to outperform (say) a Lav triple or /7 airhead. At least, in real-world riding. More than a few did just that, and those investors were rewarded when the road began to climb. By all accounts a racer with lights – especially in Hi-Po Yoshi tune. No question Bimota’s SB2 lives among the finest, fastest sports bike of the 1970s.

Catching an SB2 might be harder than ever now, as most of the 140 built are stashed in museums or private collections. This premium example, owned by Bob Steinbugler of Bimota Spirit is among the best. Nothing less than THE absolute authority on Bimota in the USA, Bob hosted journalist/humanitarian Neale Bayly for a riding interview, and these photos came from that meeting, Built from the kit, Steinbugler‘s SB2 is fit with the 810cc (listed by Bimota as 850) Yoshimura tuning using 69mm hi-comp pistons in a bored Suzuki cylinder, Yoshi ‘Road and Track’ cams, racing valve springs, valves/porting, and 4-into-1 Yoshimura exhaust. 29mm Mikuni ‘Super carbs’ were available at extra cost. Rated near 100-hp, the SB2 was good for 140-plus, with appropriate gearing. Represented by Paul Puleo of Moto Sport in 1978, Cosmo took over importing duties with the release of the 1000cc SB3. Few were made, but an intermediate ‘SB2/80’ used the previous chassis with 750cc engine and SB3 body kit.

Displayed as period mechanical art, the SB2’s performance was not equaled by the mainstream makers until it was copied. That is how Bimota should be remembered, if indeed the name isn’t resurrected again. Much was accomplished at Bimota after Massimo Tamburini moved on, but even the most radical designs to follow failed to match the SB2’s hypersonic jump to the future. That kind of impact usually translates into premium value, making it unlikely you’ll find one on the cheap. Comparatively speaking Bimota continues to rate as undervalued, which is another financial trait shared with its special frame cousins. Good for us, because I can’t imagine letting it sit if it were mine.  Nolan Woodbury

1978 Bimota SB2
Owner: Bob Steinbugler
Designed and engineered by Massimo Tamburini
Engine: (as equipped) DOHC 810cc, 2v, air-cooled inline four. Rating: 95-hp @ 8.700 rpm
Frame: Bolted and welded chrome molybdenum steel. Engine as stressed member
Suspensions: Ceriani 38mm front fork, one Corte & Cosso monoshock
Brakes: Twin Brembo 280 mm single discs (front) one Brembo 260 mm single disc (rear)
Wheels: Bimota/Campagnolo magnesium alloy.
Note: Aluminum fuel cell
Production: 140 SB2’s total between 1977-1979

Bruno DePrato Bimota’s closing
Bimota Spirit
Neale Bayly Rides: Bimota SB2


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