A recent chat involving some of the world’s most experienced motorcycling journalists revealed a simple consensus, if they could only own one new bike to do it all, then it would be a BMW GS1250. The group included ex-racers and bike testers who have ridden every new bike for decades – and the owner of this here custom is lucky enough to also own one of the famed new GS machines. The problem is they’re almost too good, they lack character, sound and the sort of mechanical involvement that makes you feel like you’re in charge of your machine. So, to get that kind of experience, the client commissioned Poland’s 86 Gear Motorcycles to build him a custom, and this 1978 BMW R100S delivers him a character filled ride in a beautiful all-round package. 

Based in the capital city of Warsaw, 86 Gear is the brand child of Christian Boosen, who has had a lifelong obsession with two-wheels. He’s a guy who has always ridden as often as he can, from Vespas in the backstreets to epic journeys across Europe, and millions of miles in the saddle has taught him as much about what makes a bike truly great, as has wrenching on them in his garage. The result is the bikes he builds are all much more than just a pretty face, they’re great to ride too, and it was this kind of service his client was looking for.

“The brief was simple: Build an elegant, classic 2-valve air-cooled boxer that feels like a modern bike. Take no compromise on safety and reliability, as the bike is meant to cut through crowded streets of the Warsaw metropolitan area daily,” Christian tells us of his client’s needs. But before a spanner could be spun, he needed to find a donor and being the well travelled man he is, Poland’s lack of classic machines doesn’t pose a problem. It was in Germany that he tracked down the old ’78 and it was in reasonable shape when he loaded it onto the lift to start full custom build number 85 of his career.

Stripped back to a bare frame, forty-five years of dirt and grim had to be removed from the round steel and any of the tabs, brackets and bolt holes that weren’t going to be used, were either cut off or filled in for a smooth finish. Sport-Evolution in Germany provided the beautifully neat subframe that is a bolt-on conversion and delivers a higher riding position and hooped rear. Finishing off the chassis is a set of crash bars and with everything sanded smooth, the whole thing was sent out for a black powder coat finish.

To get the bike rolling, Christian had no intention of relying on the stock suspension to deliver tight handling for those narrow back streets. Instead, he turned to a sweet handling machine in the form of a Kawasaki ZX7R to donate its forks and lower triple clamp to the project. Having been cleaned up and rebuilt for the job, an aftermarket upper clamp helps to secure the Japanese units into the German frame and they look damn fine as a result. The rear shocks are from YSS and are specifically designed for the model, with a host of adjustments available on demand.

Those gold legs start the visual transformation of the R, and they look right at home sitting tight next to the panel beaten to perfection stock tank. It’s been lifted slightly at the rear on a new mount and fitted with a billet filler cap, before it was turned over to the guys at Artbrush Workshop who took care of laying down the stunning racing green, with the classic BMW logos left to shine through. Behind this, Poland’s own Projekt X Nadarzyn took care of forming the foam and then upholstering the seat in gorgeous black leather with a diamond stitch.

While these parts were out of the shop, Christian was able to focus on the power plant and the engine has undergone a complete rebuild. A new forged piston set slots into the honed bores and the entire motor was rebuilt with new seals and gaskets throughout. The gearbox was given the once over, before being backed by a new clutch and a smaller starter motor has been added to the mix.

The stock Bing carbs have been rebuilt to provide smooth fuelling and the standard airbox is retained for the clean look and simplified jetting. Which did need to be a little larger thanks to the freer flowing exhaust that ends with a pair of chrome cigar mufflers.

Like the rest of the bike, the electricals have all been replaced, with the engine benefiting from a Silent Hektik alternator and ignition system. The rest of the loom is handbuilt, running off a Li-Po battery and feeding everything from a host of Motogadget parts, to a modern BMW R nineT headlight at the front end.

To ensure the BMW was as practical as possible, Christian hand-rolled a set of short fenders and added Renthal bars. It’s here that you grab the brake lever, with the new master cylinder pumping modern Tokico calipers onto twin drilled discs.

He’s one bike away from matching the number of builds his shop is named for, but Christian Boosen has once again nailed the brief, building a classically cool R100 for when that perfect GS just won’t do.

[ 86 Gear MotorcyclesInstagram ]