There is a distinct, mechanical poetry in the way a Boxer engine hangs in a custom chassis, the massive cylinders jutting out like a pair of clenched, aluminum fists. In 2021, that physical presence was the canvas for some of the most radical, boundary-pushing custom motorcycles the world had ever seen.
From Formula 1 engineers moonlighting with superchargers to master metal shapers hiding hydraulic monocoques beneath hand-beaten aluminum, the year was an absolute high-water mark for Bavarian-born creativity. The custom scene didn’t just iterate; it tore up the rulebook and rebuilt it with a distinct German accent.
In this week's Flashback friday, we are counting down the custom BMWs that stopped us in our tracks. Grab a cold drink, lean back, and enjoy as we count down the Top 10 BMW Motorcycles of 2021.
10. Myth Motor’s R80ST ‘Myth 001’ Adventure Airhead
To design the ultimate continent-crossing motorcycle, Brooklyn-based designer Matias Corea believed one had actually to cross a continent first. Drawing on the lessons of his own 20,000-mile journey from Brooklyn to Ushuaia, Matias set out to build a highly reliable, easy-to-repair overland explorer. Using a 1983 BMW R80ST as his base, he prioritized sensible, robust upgrades over pure aesthetics, ensuring every single component could be serviced or replaced in the middle of Africa.
Matias went deep into the boxer motor, increasing its capacity to 1,001 cc with high-compression Moorespeed pistons, an asymmetrical racing camshaft, and gas-flowed heads with oversized valves. Breathing through 40 mm Bing carbs and a Siebenrock exhaust, the balanced powerplant surged to an impressive 72 horsepower at the rear wheel. To handle the extra grunt and brutal terrain, master welder Esteban Pasquale gusseted the frame with 14 reinforcement plates and pivoted the subframe forward to incorporate a heavy-duty rear rack.
The chassis is supported with WP open-chamber forks offering 250 mm of travel, paired with a stretched shaft-drive swingarm and a custom Wilbers rear shock. Sturdy Excel rims, a 21-inch front laced to a Talon hub and an 18-inch rear offset to fit a 130-wide Mitas dual-sport tire, shod the adventure build. Completed with an 11.3-gallon nylon HPN fuel tank, dual-curve ignition to combat low-quality fuel, and a minimalist livery by Robbie Nigl, this build stood as the ultimate prototype for world travel. [MORE]
9. 46works’ R100RS Sports Restomod
Shiro Nakajima, the multitalented force behind Japan's 46works, brought his extensive background in vintage racing and engineering to bear on a late-generation 1992 BMW R100RS. Commissioned to build a sports-focused machine that favored winding roads over long-distance touring, Shiro stripped away the heavy factory fairings and focused on shedding weight. The result was a razor-sharp, incredibly clean restomod that bridged the gap between show-quality detailing and pure track performance.
The air-cooled boxer engine and gearbox were completely overhauled, blasted clean, and blueprinted back to factory specifications. Shiro replaced the stock Bing carburetors with highly responsive, flat-slide Keihin FCR39 units and fabricated a gorgeous, full-titanium 2-into-1 exhaust system ending in a one-off titanium muffler.
Up front, inverted Öhlins forks scavenged from a Ducati were internally modified and secured with a custom-machined steering stem and triple clamps. The rear end featured an Öhlins monoshock connected to a beautiful, custom-machined rear hub, with 18-inch Excel rims wrapped in Bridgestone Battlax rubber.
Shiro hand-shaped a stunning, angular aluminum fuel tank with elegant knee indents, which flowed seamlessly into a modified subframe carrying a solo seat and a compact tail unit. Finished in a striking French Blue inspired by classic British sports cars, this build proved that pairing Japanese craftsmanship with German engineering is a foolproof recipe. [MORE]
8. Engineered To Slide’s R nineT Chopper
Nigel Petrie of Australia’s Engineered To Slide took a path rarely traveled by receiving a brand-new BMW R nineT Racer and deciding to turn it into a skinny, elegant chopper. Nigel threw away almost everything except the boxer engine, the rear drive unit, and the rear brake, choosing to build a completely custom chromoly frame from scratch. The frame's clean lines were established using traditional string lines, resulting in a hardtail layout that hung the modern engine like a piece of industrial art.
The most captivating feature of the build was the skeletal, girder-style front fork, which Nigel fabricated from 19mm chromoly tubing and paired with a hand-baked, five-layer carbon fiber leaf spring. The wheels were equally spectacular; Nigel designed custom BMX-style 'snowflake' aluminum spokes, laser-cut and welded to 22-inch and 18-inch rims.
In a bid for ultimate mechanical purity, Nigel ditched the factory fuel injection and electronics, installing a Morris Magneto driven by dry-sump pulleys to emulate a 1960s drag car supercharger. Billet Smart Carbs handled fueling, while a DeWalt battery was tucked beneath the motor to run the starter and lights. Complete with custom titanium intakes, high-swept pipes, and foot-operated controls, this chopper stood as a masterful, jaw-dropping blend of high- and low-tech design. [MORE]
7. Bolt Motor Co.’s R100RT Racer
Valencia-based Bolt Motor Co. has a background in racecar preparation, and shop boss Adrián Campos brought that high-performance pedigree to a 1981 BMW R100RT. The air-cooled 980cc boxer twin was rebuilt by former Formula E race engineer Juan Fernandez, who converted it to a dual-plug setup to run high-compression pistons. Mikuni carburetors, a Siebenrock deep sump cooling kit, and straight 2-into-1 pipes terminating in a Spark muffler rounded out the potent engine package.
The mechanical engineering got even wilder when the team decided to graft the single-sided swingarm of a modern BMW R1200S onto the forty-year-old R100 gearbox. This update required adapting the Paralever attachments to a section of the R1200S chassis, reshaping the swingarm, and installing a race-spec Hagon rear shock. Up front, Bolt fitted the massive Öhlins forks and front wheel from a Ducati Panigale 1299, pairing them with dual 330mm discs and Brembo M4 monobloc calipers.
The sleek bodywork featured a heavily modified vintage fiberglass front fairing, a slightly repositioned stock fuel tank, and a 3D-printed carbon-fiber tail section that appeared to float in mid-air. Juan Fernandez worked alongside Engiser 101 to build a race-grade wiring loom, connecting a Motogadget Mini speedo, Rebelmoto switchgear, and a powerful lithium battery. It was a masterpiece of mechanical hybridization that set a staggeringly high standard for airhead customs. [MORE]
6. Two Wheels Empire’s ‘Casino Royale’ K1100 RS
Lithuania's Two Wheels Empire decided to exit the custom motorcycle industry to focus on e-bikes, but they ensured they went out with an absolute bang. Their farewell build, nicknamed 'Casino Royale,' was a brooding, ultra-premium 1991 BMW K1100 RS that refined their signature 'flying brick' template. Tearing down the bulky, plastic-clad 90s tourer, the team aimed for structural minimalism and high-end componentry to create their most sophisticated build to date.
They discarded the stock three-spoke wheels in favor of classic K100 octagon hoops, widening the rear rim to fit a beefy 160-wide Pirelli Angel GT tire. The front end was modernized using gold Öhlins forks and twin Brembo brakes sourced from an Aprilia Tuono 1000 R, held in place by CNC-machined Powerbrick triple clamps. A custom fiberglass tail section and premium leather seat from Twisted Brothers sat atop a custom subframe, giving the bike a sharp, nose-down cafe racer stance.
The bodywork was finished in a beautiful Mercedes Selenite Magno Grey, accented by custom artwork inspired by Ian Fleming's original Casino Royale book cover on the tank. A custom-built 4-into-1 exhaust system snaked beneath the engine to exit via a tidy, underslung box muffler, while the intake breathed through free-flowing K&N pod filters. Rewired with a Motogadget mo.unit controller, a keyless ignition, and a Harley-Davidson LED headlight, this was the ultimate tribute to the legendary flying brick. [MORE]
5. 10 ’til 12’s Supercharged R100RT ‘R107K’
By day, Ben Norton works as a designer for a prominent Formula 1 team; by night, he builds custom motorcycles under the banner "10 ’til 12." This professional background explained the uncompromising engineering behind his supercharged 1992 BMW R100RT, dubbed the 'R107K.' Ben dropped a 1,070 cc Siebenrock big-bore kit into the boxer motor, rotated the entire engine slightly upward to align the drivetrain, and built a custom-engineered multi-link rear suspension around a BMW R nineT final drive and a Ducati Panigale shock.
The undisputed centerpiece of the build was an Eaton M24 supercharger, installed to capture vintage aero-engine nostalgia and deliver relentless low-end torque. To make it work, Ben’s friend and fellow F1 engineer CNC-machined custom timing and front engine covers to support the supercharger belt drive, along with a custom carburetor duct and intake plenum. The supercharged engine breathed through a single Mikuni HSR carburetor and relied on a custom-programmed methanol injection system to keep combustion temperatures down.
The bodywork was equally spectacular, featuring separate aluminum fuel and methanol reservoirs hidden beneath a hand-laid carbon fiber tank cover that mimicked classic R100 proportions. The cockpit integrated S1000RR front forks, custom Aximech triple clamps, a Motogadget dash, and Magura HC1 master cylinders. Wrapped in a stunning mechanical-themed livery by Pro-Kustom, the 188 kg machine was an incredible showcase of F1-level CAD modeling and fabrication. [MORE]
4. Vagabund Moto’s ‘Tin Man’ R nineT
Austria's Vagabund Moto has never been a workshop to rest on its laurels, but its 15th build, based on a 2016 BMW R nineT, pushed custom design into the future. Commissioned by a client who asked for their best motorcycle ever, founders Paul Brauchart and Philipp Rabl chose to create a modern reinterpretation of their famous 'Whale' monocoque build. To execute the complex metalwork, they collaborated with metal master Bernard Naumann, better known as Blechmann, giving the bike the fitting name 'Tin Man.'
Blechmann hand-shaped an incredible outer monocoque tank cover and seat unit, which concealed an inner monocoque housing the actual fuel tank and a storage compartment. At the press of a remote control, a custom latch released the outer shell, causing it to slide upward and backward on smooth hydraulic shocks. An acrylic window in the outer cover allowed the rider to read the Motogadget speedometer when closed, which then pivoted on its own custom hinge when the bodywork opened.
Vagabund managed to keep the bike fully street-legal for its destination in Spain, neatly packaging the factory key, fuel pump, and electronics inside the custom bodywork. The bike rode on full carbon Rotobox wheels wrapped in Pirelli Diablo Supercorsa SP tires, with high-end Rizoma foot controls and clip-ons finishing the cockpit. Painted in Mercedes Selenite Grey Magno with clear-coated raw aluminum sections, Tin Man stood as an unbelievable triumph of futuristic industrial design. [MORE]
3. NMoto’s C400 ‘Golden Age’ Scooter
Miami-based NMoto turned the scooter world upside down when they debuted their Golden Age concept, based on the modern, angular BMW C400 X. Now fully in production, this art deco masterpiece was designed to evoke the pre-war elegance of the famous 1936 Henderson custom built by O. Ray Courtney. To bring the curvaceous, vintage shape to life without adding excessive weight, NMoto partnered with Zillers Motorcycles to manufacture a lightweight, seven-piece carbon fiber composite body shell.
Underneath the beautifully sculpted body panels, complete with an iconic BMW kidney grille and retro chrome details, sat the reliable and highly practical C400 X platform. This meant the scooter retained all of its modern factory conveniences, including ABS, automatic stability control, a heated seat, a 6.5-inch Bluetooth-connected TFT display, and spacious under-seat storage. The 350cc, 34 horsepower single-cylinder engine was routed through a custom, heat-shielded exhaust system that exited via a small grille in the rear fairing.
Despite its bulbous, low-slung appearance, the Golden Age was designed to be highly rideable, boasting a respectable 35-degree maximum lean angle and a top speed of 90 mph. NMoto offered the Golden Age as both a turnkey, completed motorcycle and a do-it-yourself kit, with premium options such as custom upholstery, air suspension, and chrome luggage racks. It was a polarizing, beautiful leap backward in time that brought supreme style to the daily commute. [MORE]
2. Ironwood Custom Motorcycles’ K100 Cafe Racer
Arjan van den Boom and his crew at Ironwood Custom Motorcycles have built a massive following around their signature hyper-graphic, aggressive, and nose-down custom style. When a German client asked them to apply their radical 'Mutant' design style to a 1987 BMW K100, they jumped at the chance to tame the bulky flying brick. The team began by de-tabbing the frame and swapping the front end for gold inverted Öhlins forks from a Ducati Panigale, clamped in custom CNC-machined triple trees.
The entire 987 cc four-cylinder engine was stripped down to the crankshaft and completely rebuilt with fresh OEM internals, while the gearbox and shaft drive received the same treatment. The upgraded engine management setup utilized a remapped SC Delta ECU, larger fuel injectors, a race-spec radiator, and a bespoke stainless steel exhaust system ending in an Akrapovič muffler from a Honda CBR600RR. A custom wiring loom was built around a Motogadget m.unit blue controller and a BEP 3.0 instrument conversion box to modernize the electrical system.
The K100's stance was finalized with a custom Wilbers rear shock and a signature stubby, parallel subframe carrying a gorgeous black leather seat upholstered by Silver Machine. Jacco of Royal Kustom Works executed the breathtaking black-and-gold paint finish, detailing the fuel tank, air intake, and engine covers to highlight the bike's mechanical lines. It was a flawless, high-contrast machine that proved K-series custom design could be incredibly elegant. [MORE]
1. Kingston Custom’s ‘Spirit of Passion’ R18
Topping our list for 2021 was a machine that redefined the limits of factory-supported customization: the 'Spirit of Passion' by Dirk Oehlerking of Kingston Custom. Commissioned directly by BMW Motorrad, Dirk chose to leave the frame and massive 1,802 cc boxer drivetrain 100% original, focusing instead on sculpting a spectacular visual masterpiece. Relying on his analog design process, Dirk carved the breathtaking Art Deco bodywork from rigid foam before molding the final shell in lightweight fiberglass.
The massive, sweeping front fairing and matching rear wheel enclosure bolted directly to the stock R18 mounting points, with the rear guard attached to the swingarm to follow the wheel's movement. Up front, a beautiful, hand-slatted aluminum 'kidney' grille paid direct homage to the classic 1936 BMW 328 sports car, sitting below a deeply recessed Highsider LED headlight. The handlebars were custom-fabricated to sweep backward inside the bodywork, ensuring the bike maintained its factory turning circle and a rideable 150 mm of ground clearance.
Finished in classic BMW deep black paint with crisp, hand-painted white pinstripes and a vintage R75 tank badge, the Kingston R18 looked as if it had rolled out of a pre-war German design studio. Yet beneath the breathtaking retro-futuristic bodywork lay a modern, highly reliable cruiser that started at the press of a button. It was a towering achievement in Oehlerking’s custom career, securing its place as our undisputed number-one BMW of 2021. [MORE]
Comments