BMW's R18 is the definition of a modern classic motorcycle

BMW's R18 is its latest heritage-inspired bike and uses its biggest boxer engine ever.

The air- and oil-cooled 1.8-liter opposed twin engine makes 91 horsepower and 116 pound-feet of torque.

The bike uses an exposed shaft drive, a hardtail-look frame and lots of chrome to evoke the 1936 R5.

The R18, like the R NineT before it, is designed to be easily customized.

BMW is offering a full line of custom parts designed with industry powerhouses like Mustang Seats and Roland Sands Design.

The bike features cruiser styling but a midmounted foot control, which should make the bike more fun to ride than it would otherwise be.

The bike hews fairly close to the well-received R18 concept bike that we saw last year at Villa d'Este.

The production bike's biggest changes come in the form of a smaller diameter front wheel and a more emissions-friendly exhaust system.

The R18 will be offered in two variants at launch: standard and First Edition.

First Edition will feature black paint with white pinstriping as well as added chrome touches to more closely mirror the original R5's styling.