Zonnevlek Harley-Davidson Street 750

During my visit to Japan with Harley-Davidson late last year, we were introduced to 5 Japanese builders whose workshops had been invited to each customise one of the new H-D Street 750's. The project was coined the "Street Build Off" and the 5 workshops involved included Cherry's Company, Asterisk, Duas Caras Cycles, Luck Motorcycles and Custom Works Zon. Only a few short months later the builders unveiled their creations at the Mooneyes Hotrod and Custom Show in Yokohama, where a panel of judges awarded one workshop as the outright winner. Taking home the prize was Custom Works Zon with their heavily customised 'Zonnevlek' Street 750 racer.


The Zonnevlek (meaning Sunspot in Dutch) was the brainchild of CW Zon duo Yuichi Yoshizawa and Yoshikazu Ueda. Since 2003 the pair have been building unique v-twin powered choppers and bobbers, gaining international attention in 2007 with their entry into the AMD Championship of bike building.

With the opportunity to customise Harley's newest family member the duo made the brave decision to depart from their usual traditional chopper styled builds. Inspired by the Street 750's already impressive 4.6 second 0-60mph acceleration and mid 13 second 1/4 mile capability they opted to build a motorcycle that would focus on improving straight line speed...with a modest sprinkling of aesthetic eye candy.

Taking a mere 3 months to complete the Zonnevlek is an almost complete redesign of the H-D Street with only part of the original frame and the stock 750cc engine remaining untouched. To make the most of the bikes power dropping weight was paramount, so the build began with a dramatic frame redesign. The standard half duplex frame was rebuilt using a single cradle design with custom made mounts and braces to secure the engine firmly in place. In need of a new home the bikes radiator was relocated to beneath the bike adding weight to its rear end for improved traction and a lower the centre of gravity.

The Zonnevlek's angular tank functions as a cover, concealing electrical components and the complex linkages of the "jockey" shifter. A single lever on the custom made handlebars actuates the front brake and engaging the clutch is left up to what was originally the gear selector pedal. Tucked beneath the seat is a fuel cell containing enough juice for a sneaky, backstreet burn or a few, flat out 1/4 time trials and the original instruments have been replaced by a function focused Autometer tacho.

Up front is a one of a kind set of custom made forks holding a 19 inch wheel wrapped in Avon Speedmaster Rubber. In the rear is a CW Zon signature style single sided swingarm with mono shock suspension and a 15 inch Rocket Racing wheel wearing a classic Hoosier drag slick. To free up a few more horses from the liquid cooled v-twin a custom made exhaust system and intake have also been added and fuelling remapped to suit.

As you study these photos more and more of the Zonnevlek's incredible details become apparent. From the alloy bushes, braces and panels to the brass highlights. It's the stark grey paint and contrasting gold leaf pin striping by Mr.G and the intricate engraving by 4 Dimension Studio that really push the boundaries on this build though. While straight line bikes aren't usually our thing, it's easy to see why this beast won over the Street Build Off judges. It's yet another example of why Japanese builders lead the way with their creativity and craftsmanship in the custom motorcycle scene and I can't get enough of it!

First published by returnofthecaferacers.com