A Supercharged Bmw R100 Built By An F1 Designer

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Ben Norton builds custom motorcycles under the moniker 10 ’til 12, because those are the nighttime hours he dedicates to his hobby. During the day, he’s a designer at a works Formula 1 team. Which explains why his supercharged BMW R100RT is so damn mental.
Born and raised in Zimbabwe in southern Africa, Ben now lives in Oxfordshire, UK, where he wrenches out of a single home garage. He’s spent enough time in F1 to know how to make clever choices in manufacturing and materials, and what to outsource. He also has enough equipment in his home workshop to handle most things—but jobs like CNC machining, upholstery, paint and coating are all farmed out.

It’s hard to believe, but this BMW is only Ben’s second build. The first was an R80RT café racer, which he started at the same time as a friend who had a Ducati Monster project. Ben finished his first, so decided to rub salt in the wound by kicking off a second build—an R100.
“As a dare, the same friend suggested I should add a supercharger in an attempt to slow me down and buy some time for him to finish his project,” Ben jokes. “I enjoy a challenge, and the R80 cafe racer build was over too easily!”

Aiming for an aggressive street tracker style, Ben nicknamed the project the R107K. The 107 references the 1,070 cc Siebenrock kit he’s dropped into the motor, and the ‘K’ stands for Kompressor—the usual German designation for supercharged vehicles.
To call Ben’s work on the 1992-model BMW extensive would be a gross understatement. The engine work extends far beyond just the big bore kit, with modifications to the block itself to lighten it. Ben has also added low compression copper head gaskets and twin spark heads, and revised the breather system. The engine’s even been rotated nose up, so that the drivetrain runs in a perfect line.

Taking center stage is an Eaton M24 supercharger—but Ben tells us that he didn’t just install it for extra power. “The intent rather was ‘aero engine’ nostalgia,” he says. “The challenge, the sound, and having tons of low end torque, of course.”
Most of the setup consists of custom made pieces, a lot of which were CNC-machined by a friend of Ben’s: Fred, a fellow F1 engineer at Aximech in Sweden. Fred milled out new timing and front engine covers to accommodate the supercharger belt drive, which works with a custom-made brushless alternator. He then created the custom carb duct, inlet plenum, and a pair of ‘knuckle duster’ valve cover retainers.

Ben also installed a Setrab oil cooler with a remote filter sump from Motoren-Israel, and a Toyota starter motor. The clutch was converted to a hydraulic system, with a custom billet actuation arm. Ben credits Jochen Siebenrock for his endless advice on the internal mods.
The engine breathes in through a single Mikuni HSR carb with a DNA air filter, because “fuel injection would have been too easy, and would not be right on an airhead.” Ben also installed a methanol injection system to keep the engine cool, because he couldn’t fit an intercooler into the mix. It uses a DIY ignition and methanol control computer.

The exhaust is custom too, with mandrel-bent (and tuned) stainless steel headers, terminating in a TYGA MotoGP-style muffler.
Mixing petrol and methanol meant that Ben needed reservoirs to hold both, so he fabricated separate aluminum tanks for each. Then he mounted them underneath a carbon fiber skin that mimics the classic R100 shape, but with lines to match his build. There’s a methanol pump and level sensor under there too, and the filler caps and breather valves are from Newton.

Further back is a custom seat, wrapped in Alcantara and leather by Scottish artisan Tom Hurley, with subtle bronze and charcoal accent stitching. It uses a CNC-molded foam insert to hold its unusual shape, with a stainless steel seat pan, and the subframe underneath is custom. The rest of the frame has been slightly modified with brackets and mounts for various bolt-on items, and powder coated in satin black.
It’s the swingarm and rear suspension that’s really intriguing, though. Ben started with the final drive assembly from a BMW R nineT, modified it heavily with a custom driveshaft, and built his own underslung, multi-link rear suspension setup. It includes a Ducati Panigale shock, and a ride height adjustment system to fine-tune the bike to the rider.

The front forks came off a first generation BMW S1000RR, and are held in place by custom triples from Aximech, with an integrated Motogadget dash, hidden bolts and internal wiring. The wheels are also R nineT units, wrapped in Metzeler Sportec M9 RR supersport tires. The brakes are a combination of Brembo and R nineT components, with custom lines and Atec motorsport fittings.
Ben fitted a plethora of Motogadget parts, including the turn signals, mirrors, a keyless ignition and their mo.unit control box. The custom wiring harness was built to race standards, as you’d expect, and runs off an Antigravity battery hidden under the tank cover.

Up in the cockpit are a set of ‘fat bars’ with a custom clamp, a Domino racing throttle, switches with color-coded LEDs from Rebelmoto, and Magura HC1 brake and clutch controls. There’s a Koso Thunderbolt LED headlight out front, and a set of Tarozzi foot pegs lower down, with custom linkages for the brake and gear shifter.
Pro-Kustom handled the paintwork, wrapping the carbon fiber tank cover in an exquisite livery that emphasizes the brutal mechanics of this build. It’s complemented by a host of Cerakote’d parts, courtesy of Tactical Coatings. And if you’re wondering why it looks so cohesive, it’s because Ben mapped out the entire build with CAD software, updating it as he went.

The BMW’s dry weight sits at around 188 kilos (415 pounds) now—about 30 kg less than stock. Ben hasn’t put it on the dyno yet though, because he’s still running it in. “I’m only running 0.5 bar boost,” he says, “but I plan to run more boost and methanol in the future, once confidence is gained.”
It took Ben 18 months to wrap up the R107K, and frankly, we’re surprised he did it that quickly. It’s a remarkable build for a hobbyist, and we can’t wait to see what he’s got planned next.
Ben Norton Instagram | Images by Christopher Bailey



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