Alex Earle broke onto the custom scene emphatically ten years ago, when he designed a monocoque carbon fiber body for the iconic Ducati Monster M900. The first Earle Motors build was a stunner with 19? wheels, wide bars and oversized number boards; a street tracker before street trackers were cool.
Alex has replicated that kit a number of times since, in both fiberglass and carbon fiber variants, and even adapted it to fit Suicide Machine Co.’s mental Harley Softail. But he’s always wanted to revisit his original Ducati design, with a twist: a much bigger emphasis on performance. So he’s built another signature Earle Motors bike?only this time, it’s a track-focused brute.

Alex chose the 2007 Ducati Monster S4RS for this project, for its legendary Testastretta motor and worthy parts spec. His goal was to reimagine his original Monster street tracker as an upright, high-bar superbike. ?After building several carbureted M900?s I really wanted to step up on power,? he tells us, ?and I was suspension-shamed at a few track events! I really wanted fully adjustable suspension and great brakes, and the S4RS has all of that stock.”

?I reached out to Victor at Moto Club Santa Monica to keep an eye out for a solid donor, and he found one that a customer was looking to move on to a good home. It was well loved and already had myriad performance enhancing mods. The previous owner was an airline mechanic who took meticulous care of the bike and gave her...