Few machines are as ripe for customization as motorcycles. They're pure mechanical simplicity. Two wheels, an engine, a transmission, some brakes and handlebars, and endless possibilities. Go to any motorcycle race and walk through the parking lot. You won't find two bikes that are exactly alike. If dogs are a facsimile of their owners, motorcycles are their two-wheeled equivalent. Nobody understands this better than Chris Hunter. He's the editor of one of our favorite motorcycle sites, Bike EXIF, which highlights the best custom rides from around the world with beautiful photos, thoughtful descriptions, and interviews with the personalities behind the machines. And now he's turned his popular site into a book: The Ride. We asked Chris to list the 10 best custom machines to come out in 2013, and here's what he came up with. Above: BMW Concept 90 Roland Sands Design and BMW Motorrad Bike manufacturers and customizers rarely work together, but if they would, we'd see more awesomeness like the Concept 90. BMW Motorrad designers Ola Stenegärd and Sylvain Berneron teamed up with Roland Sands Design to create an homage to the R 90 S, and the result is one of the cleanest, most comprehensive builds of the year. Sands took design cues from the classic Morris design and cranked it up to 11, creating custom body work to form around the air-cooled boxer engine, and keeping the polished metal to a minimum to make the black and orange theme sing. Of all the bikes in this group, this is the one we'd ride home. And to the coast. And across the country. Photo: BMW

Ducati Petardo El Solitario MC - Spain Few shops are making waves in the custom bike world like El Solitario MC. The garage in Spain is headed up by David Borras, and his aesthetic is the antithesis of the stripped down, minimalist cafe racers that are all the rage. Based on a 1993 Ducati 900ss, the Petardo could play alongside Mel Gibson in a Mad Max remake. Everything is exposed and overtly rugged, with a stack of race gauges on the tank flanked by buttons and switches, and a pair of massive headlights to break through the dust. "We were so tired of the never-ending flock of internet customs with the same ironing-board-like seat, fake Bates headlight and Wi-Fi electrics," says Borras. "We just needed to do the contrary and make fun of it." Contrarians unite! Photo: Kristina Fender

Thrive T003 Káku Indra Pratama - Indonesia We take it back. This is the one we want. It's called the Thrive T003 Káku, and underneath that sci-fi bodywork is a pedestrian Yamaha Scorpion 225 that's been meticulously customized by Indonesian tuner Indra Pratama. If a Japanese superhero needed a two-wheeled sidekick in a post-apocalyptic hell-scape, the Káku is it, with hand-fabricated bodywork coated in a burly matte paint. You won't find another Yamaha 225 like it, which makes the fact that it's Pratama's first build even more impressive. Photo: Putra Agung

Mule Web Surfer II Mule Motorcycles - California It's called the Web Surfer for a reason. Most of the parts came from eBay and the seat is made from a vintage surfboard. Naturally, it comes from California. Built by Richard Pollock at Mule Motorcycles, the former aerospace metalwork specialist is obsessed with perfection, and the level of detail wrapped around the Buell 1200 motor and C&J mono-shock frame deserves a second -- and third, and fourth -- look. Photo: David Edwards

DP Customs Del Rey Jarrod and Justin Del Prado - Arizona F1 fans will recognize the Del Rey's paint scheme immediately. It's a Harley-based homage to the 1971 constructors' championship commissioned by a vintage racing obsessed rider. With a rebuilt 1995 Harley-Davidson Sportster 1200 as its base, the brothers from DP Customs went to work stretching the hard tail out four inches and boosting the v-twin's engine with a massive intake and custom exhaust. Just watch your foot when you lay into the brake pedal. Photo: Jed Strahm

Fuel R80S Trial Karles Vives - Spain Most custom bikes spend their lives in carpeted, air-conditioned garages. For Karles Vives, that's unacceptable. The Barcelona builder organizes a 10-day, 1,250-mile tour of Morocco designed for vintage enduro bikes, and the R80S Trial is the personification of his "Scram" event. The 1984 BMW R80 ST underwent a five-month makeover, and would look at home crossing a desert in Africa or storming the Alps in Austria. As it should. Photo: Claudio Rizzolo

Yamaha XJR1300 Monkeefist Yahama Europe and Wrenchmonkees - Denmark The Danish design aesthetic makes it to two wheels with a joint project between Yahama's European arm and the Copenhagen-based team at Wrenchmonkees. It's a big bruiser of a custom, based on the 1,251cc XJR1300 retro rocket, but with the forks replaced with a set from the YZF-R1 to lower the stance, clip-on bars to get you hugging the tank, and spoked wheels the contrast nicely against the modern suspension and six-piston brakes. As far as big bikes go, this puts nearly everything from Milwaukee to shame. Photo: Wrechmonkees

Kaffeemaschine #8 Axel Budde - Germany Cafe racers are becoming as common as Corollas, so it's nice to see a fresh take on an increasingly commoditized style. Hamburg's Axel Budde has been gaining notoriety for his v-twin builds, and the Kaffeemaschine #8 is the distillation of Budde's philosophy of "elementary" machines. Based on a 1980 Moto Guzzi Le Mans Mk II, the builder put the Guzzi on a serious diet, custom fabricated all-aluminum bodywork, and just for good measure add passenger pegs and a leather coated rear seat for riding two-up. It's just too bad Moto Guzzi never learned how to properly mount a v-twin. Photo: Axel Budde

Medaza Cycles Rondine Don Cronin and Michael O’Shea - Ireland Insanity has a name and it's called the Rodine. No one in their right mind would build a custom atop Moto Guzzi's FalconeNuovo -- not a pretty bike to begin with -- and made even worse with a flat single with the get-up of an asthmatic rabbit. But that's exactly what Don Cronin and Michael O’Shea did, building the custom Guzzi in their shop in Cork, Ireland. And it was good enough to not only compete at the famous AMD World Championship of Custom Bike Building in Essen, Germany. It won. Photo: Onno Wieringa