There’s something pure and striking about the motorcycle. We all know from high school Physics that gyroscopic forces generated by rotating wheels keep bikes upright, but there's still a sense of wonder to see motorcycles gliding by in a world of balance so different to cars. Where cars can default into a life of simple commuting, the motorcycle is always a whim away from adventure.
There's an inherent adventurousness about being on two wheels, never having to get stuck in traffic and always feeling the draw of that open road - to explore. It’s the reason why modified and conceptual motorcycles are so spellbinding. And individualistic. Riding is a solo pursuit. Me-time. This is perhaps why custom motorcycle concepts are such works of art. The design teams and builders pour a sense of themselves into each project, knowing it's tailored to an individual, instead of a generic product planning cycle servicing some anonymous customers.
With tremendous build constraints in terms of packaging and tiny tolerances within which to add or subtract components from a bike frame, custom and concept bike-building is an art for true fabricators and determined designers - detailed and imaginative work that can only be done by dedicated and talented humans instead of robots. From radical handcrafted cruisers, to battery bikes that balance themselves, to aircraft engines powered superbikes, we’ve compiled a list of some of the greatest custom and concept modified motorcycles ever built.
The striking Unbreakable pictured above is produced by Thunderbike, which is based in Hamminkeln, Germany. Although the engine is borrowed from Harley Davidson, the bike is almost entirely a custom build, crafted by Thunderbike’s best technicians. A team of 80 highly skilled craftspeople machine and mill everything from the split-spoke design wheels to the handlebars. The result is bike art nearly worthy of display in the Guggenheim.
Belgian custom bike specialist Krugger hasn't built a reputation producing boring bikes. The Nurb is owner Fred Krugger’s most inspired work, and one immediately notices that the front wheel is only supported by the suspension on its left side instead of being mounted on a conventional twin-legged fork.
Powering the unique Belgian bike is a 165hp BMW K1600 six-cylinder engine. Cleverly, despite its outrageous looks, Krugger has retained BMW’s best bike electronics underneath, which means traction control and adjustable suspension. So yes, there’s anti-wheelie control, but honestly, why would you ever want to get something this beautiful onto its back wheel and risk crashing it?
Few things in American engineering are quite as iconic as the World War Two era P51 Mustang fighter. To pay homage, Confederate Motorcycles, a custom builder based in Birmingham, Alabama, offers its two-wheeled interpretation of the P51.
The dominant theme of this motorcycle is its construction, where conventional tubing is replaced by a monocoque. That’s right - a single billet of aviation grade aluminum, 1,500 pounds worth, is machined and milled away until all that's left amidst the shavings of metal is the P51’s frame.
From time-trial road bikes to sophisticated racing and private cars, the Lotus name is synonymous with perfectionist lightweight engineering, most of it done with composites. That carbon-fiber heritage is perhaps nowhere more evident than on the C-01, designed by Daniel Simon.
Ironically, despite the Lotus name, the C-01 was built in Germany, instead of England, as a joint venture between renowned motorsport enterprises Kodewa and the Holzer Group. Power by a highly modified KTM 1,195 cc engine, the C-01 has as svelte a shape as you could imagine on two wheels.
As a fresh graduate from the Art Center College of Design, in Pasadena, California, Tiger Bracy was given the task of doing something very different for Minnesota-based cruiser and ATV brand Polaris. Tiger did just that with his Victory Vision 800. A work of remarkable packaging genius, the Vision 800 was powered by an 800cc parallel twin engine sourced from a Polaris ATV and had a complete absence of any foot controls, as it was driven by a continuously variable transmission and stopped with linked brakes, operating off a single lever.
It’s hardly a surprising state of affairs: a compact wheelbase and enormous power will always result in a front wheel rise at the slightest hint of poor throttle discipline. That's why people who love the four-cylinder engine character of Japanese superbikes consider a wheelbase extension to quell the habit of bikes such as the Yamaha R1 to perform involuntary wheelies here, there, and simply everywhere. CJ Velez’s stunning R1 project bike is an excellent example with its custom swingarm extending the wheelbase and a massive single-sided rear wheel providing nearly unbreakable levels of traction.
At a crucial juncture in aviation history, adventurers of the skies were told by their engineers to choose between the V-twin and the radial engine. History proved the latter superior, and the V-twin defaulted to its role as a motorcycle engine configuration with more character than most.
But what if you were crazy enough to fabricate a frame which could accommodate a radial airplane engine? It’s exactly what John Levey from JRL Choppers did. Sourcing the 2,800 cc radial engine from Australian firm Rotec, it was a severe test of Levey’s patience and skill to bend stubbornly thick tubing, which was strong enough to support the radial engine, into a shape which could also flow around all 40-inches it. With 110 hp and 160 lb-ft of torque, it hauls like crazy, and the soundtrack is everything you would expect from a 40 mm altitude compensating a Bing carburetor.
Yamaha’s BW200 was perhaps the most inspiring motorcycle to ever be marketed to novices. With a low saddle height and high-volume tires, it was nearly impossible to unbalance, especially at low speeds. Back in the late 1980s, if you wanted to train for your bike test, you did it on a BW200.
Those balloon proportion tires the BW rolled were so cool that somebody had to pay homage to it through a modern interpretation of the classic late 1980s Yamaha ‘big wheel.’ Custom bike builder John Ryland tried to revive the balloon tire theme on his gorgeous BW650 custom build using a Honda XR650L as the donor bike. Keeping those huge STI Black Diamond tires in position and adding some brand credibility to the project is a Yamaha WR250R sourced front fork.
There's a sort of heroism in the ambition of those with humble means. What you see in the image above might appear to be a Ducati Panigale, but there’s something odd about how small the rear tire in that frame appears.
This is no Italian bloodline superbike but, in fact, a 150cc Yamaha SZ-5 commuter bike. A brilliantly ambitious project from the Philippines, this Panigale imitation has a custom fairing, tank and seat cowl. Beyond the styling upgrades, mechanical improvements include tally petal discs brakes and an underbelly exhaust system. It's sacrilegious to some but a budget dream bike to others.
Italian superbikes are exclusive and plenty expensive; you're paying for the best frame building skills and expertise. But when even the most desirable of all Italian superbike brands, MV Agusta, isn't quite exclusive enough, you could always commission something unique.
It’s the story of this breathtaking MV Agusta F4Z custom, built on consignment, with absolutely no budget constraints. The owner is a fantastically wealthy Japanese enthusiast with excellent taste. The radical surfacing and detail work isn't MV Augusta’s, although the F4Z frame underneath is. Its amazing shape is the work of legendary Italian car design company Zagato.
We use them in aviation, but the turbine engine has never been welcomed in anything with wheels. Critics say turbines lack the instantaneous throttle response and modulation required for wheeled transport, and motorcycles depend on immediate reaction to any twist of the right-hand grip. But that hasn't deterred Marine Turbine Technologies (MTT) from attempting the seemingly impossible.
A specialist marine turbine manufacturer, MTT’s project bike is called the 420 RR. Powered by a Rolls-Royce M250 turbine - which also makes the Bell JetRanger helicopter fly - MTT’s goal is a superbike with 420 hp and 600 foot-pounds of torque - that last number better than most supercars, never mind superbikes.
One of the very last places you’d imagine a custom Harley Davidson street bike would come from is Ukraine. But in Kharkov, designer Yaroslav Lutytskyi busies himself dreaming up and building some spectacular bikes, and his Sturmvogel is the best example. It’s based on the Harley Davidson XR1200, with the name "Sturmvogel" invoking memories of the very first jet fighter plane, Messerschmitt’s Me 262 – which is the chief inspiration for its fairing design. The rear suspension is adjustable, and there's inspired metalwork everywhere, including front- and rear-wheel fairings. The handlebars sit within a torpedo-shaped aero pod, which, when you look at it long enough, does start to resemble a Messerschmitt Me 262 nose section.
In the hyper-competitive world of liter superbikes, there are few more respected than BMW’s S 1000 RR. With advanced traction control and exact, though never dulled responses, this BMW appeals to hardcore knee sliders and novice superbike riders alike. But what would it be like if you tried to make one as a 1980s endurance racing-heritage bike?
That’s exactly what BMW France asked Parisian design consultancy PRAËM to do. The result is the easiest to ride 200 hp superbike around, with the added appeal of absolutely striking circa-1983 styling. Custom details include an externally riveted screen, an offset headlamp, an exposed engine, and period graphics.
If you're going to call your bike company "46Works," it had better be capable of building something really special. The number 46 is revered in MotoGP, as it belongs to the legendary world champion bike racer Valentino Rossi. Shiro Nakajima’s team of master bike builders does number 46 no dishonor, though, and their custom KTM RC8 is a tantalizing Japanese café racer. Titanium and aluminum fabrication of the highest quality do the unthinkable and manage to trim 20kg off the already minimalist stock RC8 donor bike. To make one of the lightest superbikes even lighter, most of the mass savings were gained by the fuel tank, the radiator shrouds, the rear seat, and the entire exhaust system being hand-built, with human precision saving grams where required.
If you blended classic Harley power with a Bonneville salt flats speeder, what would it look like? Award-winning Canadian bike builder Richard Goldhammer knows because he built just such a thing. Beneath the exotically shaped aluminum bodywork is half a Harley V-twin engine. That’s right, kids - this bike runs a 965 cc single, which isn't only nitrous-oxide injected for additional surges of power when required but also supercharged courtesy of a Rotrex blower. To ensure the single-piston engine fires consistently, Richard even machined his own custom camshaft for the project.
Despite the Fireblade redefining what Japanese superbikes were capable of in the 1990s, Honda’s are not traditionally known for its radical bike designs. That certainly didn't stop Ian McElroy from building a superb version of the 1987 Honda Hurricane by himself. McElroy drew heavily from KTM’s RC8 superbike for his design’s inspiration, and the result is a Japanese speed machine with an appearance sure to turn heads at the traffic lights.
Aluminum is a notoriously temperamental metal to weld, but this didn’t deter McElroy from joining bits of it to create his bike's intricate bodywork and fenders. The original Honda instrumentation was binned, replaced by a Veypor setup capable of recording all the data that really matters, such as 0-60 mph acceleration, the quarter mile, and lap times.
Musical instruments and outboard motors aside, Yamaha is best known for its rich portfolio of motorcycles. But what's the future for this giant of the bike industry? The answer is called "Motoroid," a bike with artificial intelligence (AI). Electrically powered, the Motoroid sources its drive from battery cells mounted externally below the seat in chrome canisters. Converting the stored battery power to electric drive are hub motors, which work with the AI system, creating a two-wheeled counterbalancing effect Yamaha claims won’t fall over. Better yet is the absence of a kickstand, so there will be no potentially embarrassing moments attempting to heave a motorcycle upright after it's ended up on its side.
How does one interpret the purity of Porsche as a motorcycle? A challenging task, but one Spanish designer Miguel Angel Bahri was determined to at least attempt. His creation is the 618. Influenced by the legendary Porsche 911 Turbo and 918 road cars, in addition to the 919 Le Mans racer, the 618 is an electric two-wheeler with batteries mounted low to ensure excellent weight distribution. An eight-inch touch-sensitive instrumentation panel pairs with smart devices whilst charging them, giving the rider navigation and battery-range information. The craziest bit about Bahri’s design is its center steering hub, abandoning the traditional front fork.
More former Soviet Republic motorcycle designs, this time from a joint venture between Ukrainian and Belarusian industrial designers Vladimir Panchenko and Artem Smirnov. Annoyed by the overly digital workflow of modern design, the pair conceived their radical Samurai carbon concept from paper first before transitioning the idea into a computer-aided design program. Reach-adjustable brake levers, a gloriously oversized fairing, and what appears to be a sliding rear swingarm to ease chain tensioning are just some of the delicious design details. Sheathed forks aid aerodynamic efficiency, whilst at the back, twin coil-over shocks are exposed, breaking up the flowing side profile for a perfect bit of visual tension.
Better known for their cars, BMW’s motorcycle division doesn't always get the credit it deserves. Its best handiwork is the Tron-like Motorrad Vision Next 100. Design details pay homage to classic BMW motorcycles of the past. That black triangular-frame shape references BMW’s original bike, the R32, whilst the classic BMW air-cooled boxer engine casing is present, too, despite the Vision Next 100 being battery powered.
Like Yamaha with the Motoroid, BMW also claims its Vision Next 100 to be impossible to unbalance. Huge wheels and a gyroscopic self-balancing system provide such a margin of safety whilst riding that riders won’t need to wear helmets (although that isn't suggested). The frame itself is an amazing feat of composite engineering, shaped in a dramatic arc, from hub-to-hub, in carbon fiber.