There are hundreds of beautiful customised BMW Flying Bricks, and most of them begin with an angle grinder. The ungainly rear subframe disappears, a new tail section is added, and suddenly the K100’s famously awkward proportions make sense. But in Germany, where TÜV approval can be the difference between riding and parking a bike permanently in the shed, chopping the frame isn’t always an option. So when BMW specialist Sport Evolution decided it wanted a production conversion kit for the K-series, it handed the brief to one of Europe’s sharpest motorcycle designers. Instead of building another one-off custom, Jens vom Brauck of JvB-moto set himself a far harder challenge: create a BMW K100 that looks custom, bolts together with minimal effort, and stays road legal.
Jens has built his reputation by stripping motorcycles back to their essential forms, and that philosophy is written all over this K100R. Rather than reinventing BMW’s longitudinal four-cylinder icon, he studied the original design and identified what the factory had already nailed. The cast aluminium fuel tank remains untouched, its crisp wedge profile and sculpted knee recesses still defining the motorcycle’s silhouette four decades later. Everything developed for Sport Evolution exists to complement that shape, with the new bodywork carefully extending the tank’s lines instead of competing with them. It’s an industrial design exercise as much as it is a custom motorcycle.
The biggest obstacle was hiding in plain sight. The Flying Brick’s bulky rear subframe has always been the reason so many K-series customs reach for the cutting disc. Remove it, and the proportions improve instantly, but in Germany that section of frame carries the VIN, making extensive modifications almost impossible to certify. So JvB found another way. Only the final section of the frame is removed, replaced by a simple bolt-on loop that has received TÜV approval, allowing Sport Evolution to offer a genuinely road-legal conversion without asking owners to sacrifice the bike’s identity in the process.
From there, every new component serves multiple purposes. The tank cover bridges the awkward gap left by the standard seat, while the reshaped side panels disguise the bulky airbox and visually lengthen the fuel tank. Radiator shrouds conceal the plumbing that normally distracts from the engine, and a slim front mudguard and neatly integrated LED headlight complete the transformation at the opposite end. Nothing feels decorative or overworked. Instead, each panel tidies another visual loose end until the K100 finally looks as cohesive as its engine has always deserved.
That same restraint carries through to the seating position. The new saddle runs in one clean, uninterrupted line from the rear of the tank to the compact LED taillight, eliminating the stepped arrangement that dates the standard K100. Underneath, the modified frame loop remains almost invisible, while the minimalist number plate bracket hangs neatly from the rear without disrupting the bike’s profile. It’s a solution that looks remarkably natural, as though BMW’s own designers simply refined the original package rather than reinventing it.
Below the signature JvB headlight shroud, conventional forks retain classic gaiters, a new shock preserves the period-correct stance, and the familiar Flying Brick engine remains proudly exposed rather than buried beneath oversized covers. A compact Acewell speedometer and Motogadget indicators bring the electronics into the modern era, while Sport Evolution offers alternative instruments, indicator packages and number plate arrangements for customers wanting to tailor the final result.
The finish reinforces the understated approach. Almost every new component wears a matte black coating that quietly recedes into the background, allowing the fuel tank to take centre stage in a bespoke Rolls-Royce paint. At first glance it appears jet black, but under changing light subtle olive-gold metallic highlights emerge across its curves, rewarding a closer look without demanding attention. It’s exactly the kind of restrained detail that suits the motorcycle’s overall philosophy, paired with a purposeful exhaust system and discreet finishing touches that never overpower the original BMW engineering.
Perhaps the cleverest part of the project is that it doesn’t ask owners to become master fabricators. Sport Evolution has produced a conversion that enthusiasts can realistically install themselves, transforming the once awkward Flying Brick into a clean, cohesive roadster while remaining on the right side of Germany’s notoriously strict approval process. There will always be wilder K-series customs wearing upside-down forks, flash paint and hand-built frames, but this K100R proves there’s another path. By solving the Flying Brick’s biggest design challenge with thoughtful engineering instead of irreversible surgery, JvB-moto has created a kit that feels less like an aftermarket conversion and more like the BMW many enthusiasts have always imagined should have existed.
[ JvB-moto | Sport Evolution ]