M Sport: A racy BMW K100RS café racer by Bolt

BMW K100RS café racer by Bolt Motor Co.
The BMW K100RS was borderline futuristic when it hit the scene in the 1980s. Between its blocky horizontal inline-four engine and its geometric fairings, it was a significant side-step from the boxer models that the marque was famous for.

Sure, it still looks like it came from the 80s, but that doesn’t make it a bad bike. Strip off the bodywork and throw a bunch of top-shelf components at it, and you could have a sharp, high-performing café racer on your hands. Which is exactly what Spain’s Bolt Motor Co. has done to this 1986 BMW K100RS.

BMW K100RS café racer by Bolt Motor Co.
Bolt’s client had requested a BMW K100 café racer with a race-inspired aesthetic. But while most clients usually only have a vague idea of what they’re after, his ideas were very specific. So specific, in fact, that he gave Bolt a detailed, full color sketch to work from.

“The entire team was stunned when a freehand drawing of how he wanted the bike arrived at the workshop,” says shop boss Adrián Campos. “It was a drawing that was ready to frame, where every detail came to life. From that moment on, our goal was to bring that drawing to life.”

BMW K100RS café racer by Bolt Motor Co.
From the skeletal subframe to the Öhlins suspension, everything was laid out unambiguously. Performance was top of the list; no problem for Bolt, whose sister company is the Formula 3 racing team, Campos Racing.

From their shared workspace in Valencia, the team stripped the BMW K100RS down to its bare bones and got to work. It’s not the first time that Bolt has torn into a K-series BMW, so they’ve figured out a few clever ways to eke more than the original 90-ish horsepower out of it.

BMW K100RS café racer by Bolt Motor Co.
See that canister sitting on top of the engine block on the left side? That’s a custom-made intake, developed specifically for the K’s motor. Flip to the other side of the bike, and you’ll spot the relocated ignition, and a Motion Pro coolant recovery bottle.

For the exhaust, Bolt tweaked the headers and fitted twin Akrapovič mufflers. They rewired the bike too, with a Formula 3 racing-spec wiring loom and Motogadget components. Adrián can confirm that he and his team did some other “fancy things” to the engine, but he prefers to keep those secrets to himself.

BMW K100RS café racer by Bolt Motor Co.
Moving to the chassis, Bolt sourced the upside-down Öhlins forks and twin Brembo brakes from an Aprilia RSV. Getting everything to fit meant not only machining new yokes, but a whole new steering stem too. They also added a new mounting tab to the frame, to accommodate an Öhlins steering damper, borrowed from the Aspar motorcycle racing team.

The K100 retains its original wheels and Brembo rear brake, but now sports an Öhlins piggyback shock. It’s connected to the BMW’s new bespoke subframe, which features a few unique details of its own. There’s a custom seat and 3D-printed tail cowl up top, an electronics tray tucked underneath, and an LED headlight embedded out back.

BMW K100RS café racer by Bolt Motor Co.
Bolt also kept the K100’s original fuel tank, but modified it to sharpen up the bike’s silhouette, and to hide the radiator away. Also present are discreet fenders at both ends, custom made by Bolt.

An LED headlight sits up front, mounted on custom brackets. The cockpit wears new clip-ons with internal wiring, Motogadget bar-end turn signals and Highsider mirrors. There’s also a Motogadget dash, housed in a 3D-printed surround, and LED-backlit push buttons.

BMW K100RS café racer by Bolt Motor Co.
Complementing the numerous mods is BMW M-inspired paint job, masterfully executed by Ángel at Airbrush Custom. Frequent collaborator, Tapizados Llop, handled the leatherwork on the seat. If you look closely, you’ll spot blue and red threads that match the asymmetrical highlights on the fuel tank and wheels.

Other add-ons include Goodridge brake hoses, Tarozzi rear-set foot controls, and a one-off license plate mount that attaches to the swingarm. There’s a lot of detail to take in, which suggests just how many man-hours went into this build.

BMW K100RS café racer by Bolt Motor Co.
“It has been a tough build which has been hard to get out, and has needed many hours of work,” says Adrián. “We know that we have put the client’s patience to the test on more than one occasion, because the time has gone a little more than we expected. But making a work of art like this is not quick or easy.”

“In the end, the final result has been worth every day of waiting. We have managed to give life to a unique and super special motorcycle, just like its owner. I hope he enjoys it as much as we have enjoyed customizing it!”

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BMW K100RS café racer by Bolt Motor Co.