The (AC) Sanctuary of custom motorcycles just birthed the RCM-431 and it’s Gorgeous
It hasn’t been that long since Kawasaki released its 2018 Z900RS but already there are custom builds popping up everywhere. While a few local workshops were commissioned by Kawasaki Japan and Kawasaki Australia handed one over to Deus Ex Machina, AC Sanctuary’s re-imagination of the bike is a league all on its own.
The RCM-431 was built for a client in living in the north of Tokyo, at the Tochigi Prefecture. Many upgrades were necessary as this particular client already has a newer Zephyr 1100, so the AC squad needed to step up their game.
The client’s top request was for an installation of a frame-mounted bikini fairing from American Dream. And because he wanted a more comfortable position than what clip-ons would provide, the fairing had to be mounted high enough for it to interface with a pair of low-rise handlebars.
With everything now in its place, rubber mounts were added to damp any fairing vibration at speed with bars from POSH Japan and a digital speedometer tucked behind the new screen. Even the turn signals and mirrors were upgraded to “modern equivalents”.
The front ends looks impressive with new triples holding a set of Öhlins FG 424 Road & Track inverted forks that were connected to an OZ Racing wheel. Another new addition was the twin-disc brake setup, cobbled together with Brembo radial calipers, a Brembo master cylinder, SMB caliper brackets, Suntar discs and Allegri hoses.
Similarly impressive, the rear end comes with a pair of Öhlins Legend twin shocks connected to a polished Sculpture ‘wide’ swing arm with an extra width to accommodate a 5.5-wide OZ Racing wheel; both wheels are shod with grippy Pirelli Diablos. With the exception of a Nissin master cylinder, the rear brake setup is pretty similar to the front.
Does the rear end conversion sound complicated? Well, it is. From new sprockets, chain and chain slider to frame mods, the whole thing takes a significant amount of work. The frame was also replaced with a Diamond-Like Carbon (DLC) coating.
Don’t let the ‘900’on the side fool you, though. The RCM-431 actually has an 1165cc with a set of Wossner pistons that covered everything from honing the cylinders to balancing the crank. It now also runs with PAMS HF valves and a Kent cam put together with a full set of chromoly fasteners.The AC squad also added a new cooling system with the pumbling running neatly around the engine while the clutch was upgraded to a hydraulic system with a Z1000 Police-spec clutch cover and Allegri lines connected to a Brembo master cylinder.
The carbs were switched out for a row of 38mm Yoshimura Mikunis while titanium Nitro Racing exhaust system flows into a heat-polished muffler from Grenade. Other Nitro Racing bits were the rear sets, passenger pegs, the front fender and sprocket cover.
Its livery and engine coating was so effortlessly and precisely lined with gold it’s insane and combined with the big four’s iconic oversized seat and tail section, what you get is an old-school vibe with a better-than-factory effect. This is what AC Sanctuary is all about.