Björn Gericke is, by his own admission, “not a bike builder.” But he has all the makings of one.
As the son of Hein Gericke, founder of the eponymous motorcycle gear brand, Björn has been deeply embedded in motorcycle culture for most of his life. And as the owner of the technical apparel label g-lab, he has an eye for aesthetics. So while he might not have the technical chops to build a bike from scratch, he knows what works and what doesn’t—and he knows who to call to make it happen.
Last time we heard from Björn, he’d just wrapped up a custom BMW R nineT. This time, he’s opted for a classic boxer—an early-90s BMW R100R Mystic. Both bikes were executed with the help of the BMW specialist workshop Sport Evolution.
Björn and Sport Evolution go way back. They fielded a team together in the German Supersport Championship, winning the 2008 title, and collaborated on a few custom builds. SE focuses solely on customization these days, offering everything from bolt-on parts to ground-up builds.
With SE on board to handle the heavy lifting, Björn took on the role of creative director, designer, project manager, and parts orderer. The BMW R100R Mystic is one of the Bavarian marque’s more oddball designs, but it has great bones. So it was the perfect donor machine for the hopped-up street tracker that Björn had in mind.
The BMW was quickly denuded of its bodywork, before being built back up with consideration for both looks and performance. “I never just want a beautiful bike—it also has to function at a top level,” Björn adds.
The first job was to tweak the BMW R100R Mystic’s stance. The OEM wheels measured 18 inches at the front and 17 inches out back, but the vision called for a 19F/18R combo. So the front wheel was adapted to run at the back instead, with the 19” wheel from an old BMW GS taking its place.
Road-compliant Dunlop DT3-R flat track tires, scalped from an Indian FTR, were fitted next. The aging suspension needed a boost, so SE upgraded the front forks with a fully adjustable cartridge kit. The kit is a proprietary item from SE, as is the adjustable rear shock.
SE went to town on the boxer motor too, rebuilding it with a smorgasbord of parts that they’ve developed in-house. The now-1,070 cc engine sports new valves, reworked heads, a 320° camshaft, a programmable ignition, and Mikuni TM40 carbs. “The bike has close to 90 hp and 90 Nm of torque now,” says Björn.
Hattech supplied a custom-built stainless steel exhaust system. Both headers sashay their way to the left-hand side of the bike, flowing into a pair of stacked reverse-cone mufflers.
Getting the BMW’s bodywork right was high on the priority list. The team started by adapting a Harley XR750 replica tank to fit, with small tweaks to the frame to help it sit lower. An additional tube was welded in near the headstock to add stiffness.
A handmade aluminum tailpiece sits further back, designed to run perfectly parallel to the base of the tank. A single number board hangs from it on the left, leaving the rear shock exposed on the opposite side. The whole arrangement is perched atop a bolt-on SE subframe, with integrated tabs that accommodate a pair of LED taillights.
Up front, a tight-fitting aluminum nacelle hosts a J.W. Speaker LED headlight. A custom-made fork brace sits lower down, flanked by fiberglass flat track-style fork guards. Björn opted to ditch one of the R100R’s front brake discs for a leaner vibe.
The cockpit features LSL handlebars fitted with a Brembo brake lever, a CRG clutch lever, and a Motion Pro throttle. The switches are KTM parts, and the tiny digital speedo is from Motogadget.
Björn took inspiration for the BMW’s livery from a Land Rover that was restored by the Portuguese outfit Coolnvintage. The crisp colorway is set against an anthracite frame, while the engine wears mostly silver finishes. Franky at Signs with Soul added the finishing touch: hand-lettered details scattered throughout the build.
Lithe and perfectly poised, Björn’s BMW R100R street tracker hits all the right notes. “It was quite a challenge to get all the looks and proportions right,” he admits, “as the BMW frame and the engine position are all over the place. But I think we managed it quite well.”
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