Retro fever is the perfect motorcycling affliction. Hipster types love it because they totally missed the 1970s and ’80s (heh, heh). And those who were riding then may still be in the game and eager to reminisce—with better machinery. Enter Kawasaki’s Z900RS and Z900RS Café. Based on the Z900 naked bike, the Z900RS uses the same 948cc inline-four and steel chassis, outfitted with bodywork recalling the 1973 Z1 superbike. Besides hugely improved performance in all areas, deviations from the original include 17-inch cast instead of wire-spoked wheels, radial tires, a multi-adjustable inverted fork in place of the old-school conventional fork, link-style monoshock rear suspension in lieu of twin shocks, and a 4-into-1 exhaust rather than the Z1’s 4-into-4 system.