The year is 1973 and Bavarian Motor Works has just celebrated their 50th anniversary. In addition, they’ve also just completed their 500,000th motorcycle marking a momentous milestone in the companies history. What BMW didn’t know at the time was that a bike they planned to release that same year would earn the reputation of being the world’s first superbike. That bike was, of course, Hans Muth’s BMW R90S.
BMW had recognised an increasing demand for motorcycles that would make suitable production road racers and cafe racers. The R90S was the result of their research and it most certainly achieved its goal. Along with the release of the R90S came a new /6 series of motorcycles. These came in 600, 700 and 900cc variants. The largest model beneath the R90S was the BMW R90/6. Although it lacked the pizzazz of the R90S the BMW R90/6 still had a lot going for it and can be acquired these days for much less money.
Aside from the obvious differences in bodywork the R90S and R90/6 shared a lot in common. In fact, the only major differences in running gear were that the R90/6 ran 1 front disc rather than 2 and fuel was fed into each cylinder via 26mm Bing slide carbs as opposed to 38mm Dell Orto ’pumper’ carbs. Despite this, the R90/6 was noted as being capable of sub 13.5 second quarter mile passes and a top speed of 187 km/h (116mph); only 13kmh slower than its sportier sibling. This, of course, makes the BMW R90/6 a very worthy candidate for the cafe racer treatment.
Jesse Scott Baumann is a mechanic based in Lake Worth, Florida. Working out of a small single car workshop he builds the occasional bike for customers. For his latest commissioned build a client delivered a mostly disassembled 1976 BMW R90/6 to his shop seeking a resto-mod that “captured the essence of the original bike and transformed it into a cafe racer”.
The build took roughly 4 months to complete and was done during Jesse’s free time from his full-time career. To develop a concept for the build Jesse’s customer presented him with piles of reference photos. After trawling through them all he was left with a rough style guide that was based on individual design elements the customer pointed out. Jesse wrapped these all into one congruent design and was given the go-ahead.
“The most challenging part was figuring out how to design the subframe,” Jesse recalls. “The customer was adamant about using a Tuffside universal cafe racer seat. It was not easy to get it to line up with the tank. I worked with my buddy at Hutch at Hutches welding to get the subframe to work with it. He bent the tubing and welded it all up for me.” Getting the Tuffside seat to then sit right took some additional finessing. Jesse fibreglassed a tab to the rear of the cowl which now holds it flat when there’s a bum in the saddle. During this stage the frame also received a complete overhaul, removing unused tabs, welding new mounting points for the proposed exhaust and rear sets and setting things up for a flush-mounted Radiants LED taillight.
To retain the bikes classic BMW R90/6 style the original fuel tank remains in play. The front and rear fenders are original too but they’ve been shortened and modified to maintain the look of the original mouldings. Jesse has also made a small, but a very effective modification to the location of the rear fender mounts that creates the impression it’s floating over the wheel. Oshmo rear-set footpegs and pair of clip-on handlebars were introduced to setup the quintessential cafe racer riding position.
“The performance decisions were sort of touch and go on this. The customer and I went back and forth, throwing ideas at one another for about a month before finalizing most of the idea.”
The handling formula they devised involved lowering the front end by 2 inches to level out the bikes bone line. A comprehensive internal rebuild then saw the forks performance significantly improved. For rear-end suspension improvements a set of retro style Hagons were added and Continental Conti rubber adds plenty of grip. As for power, the flat-twin received a comprehensive top end rebuild and the stock carbs were torn down, vapour blasted clean and rebuilt. The exhaust now breathes more freely through a set of customary cafe racer style megaphone mufflers.
To bring the BMW R90/6 electrics into the modern age Jesse has added a plethora of Modogadget accessories. There are Motogadget m-Switch controls on the handlebars, a Chronoclassic gauge above the top clamp and bar end m-Blaze indicators. A Motogadget Mo-unit Blue handles all of the electrical comms duties and to keep things looking tidy, a Walzwerk box relocates the battery to sit below the gearbox. To complete the modern lighting overhaul there is also a Hog works LED headlight in the front.
Shop This Look
Retro styled tyres
Bar end mirrors
When the time came to choose a colour Jesse went with a timeless black and white pinstriped Motorrad scheme. Not only does this BMW R90/6 cafe racer look incredible, but Jesse also has plenty of good things to say about its performance. “The bike handles and performs wonderfully,” he says “Much better than I expected! The ergonomics of the rear sets and clip ons came out great and the Conti tires are nice and sticky in the turns.”
Who needs an R90S when you’ve got a classic BMW that looks this good?!