Good customer service can be as simple as a smile, but one of the world’s great custom bike builders takes it to extraordinary levels. He might be the owner of the hugely successful Japanese outfit AC Sanctuary, with stores around the country, nearly a thousand custom builds under his belt and a waiting list almost a year long; but Hiroyuki Nakamura will go to the end of the earth to ensure his clients are happy. He even publicly apologised to the owner of this stunning Kawasaki GPZ 900R, because delivery was going to be two weeks late. But Mr K. from the Hiroshima Prefecture is anything but disappointed, he now owns an AC Sanctuary bike to call his own, and build RCM-594 was completed with the help of a very surprising source.
Nakamura-san explains that business at AC Sanctuary has never been busier and the favourite bike amongst his clientele remains the Kawasaki Z. Most clients come into the main shop to discuss with him exactly what they want and end up ordering a burger with the lot. Then more recently the company began to offer their New Type-R package, where they still make your JDM classic one hell of a magnificent machine, but do it in a way that is a little more budget friendly. Now they are even offering what Nakamura-san calls the Start Edition, where you sit down with the man himself and pick each and every upgrade, to create a Sanctuary sensation that is truly of your own.
To make his Kawasaki stand out from the pack, Mr K. had a special request, and it came in the form of Japanese Model and Social Media star Chiparu Mizuno. She’s been a die-hard GPZ lover since she was a kid, owns a couple of her own and part of her involvement was to literally leave her mark on this machine. But first Nakamura-san and his team had to bring the bike to life, and as always they started with the best donor they could find for sale at the time. Being the model that came with the bizarre 16-inch front and 18-inch rear wheel combination, the Kawasaki is quickly stripped and put in the jig to be set up for proper conversion to a 17-inch front and rear.
Nakamura-san is a firm believer in the fact you just can’t change wheel size and leave it at that. He modifies each and every frame to suit the conversion, while also carrying out all of the mounting changes required to ensure he can run the wheel width he wishes to spec, without any clearance issues or chain problems. Then the frame receives the usual AC bracing around the headstock and the swingarm pivot point, and other key areas are gusseted for increased rigidity. Only then can the stunning Sculpture swingarm get bolted on and the bike begins the process towards a rolling chassis. The steering stem is next, another part from the in-house Sculpture brand, and it’s designed with the perfect offset for the package.
Slotted through the billet anodised trees goes a full Ohlins front-end conversion, with the internals modified to suit the owner and a bunch of adjustability for fine-tuning. The rear shock is from Ohlins too, but is built by the firm to suit Nakamura-san’s very specific requests and the needs of his 17-inch conversion. The wheels are the ever-popular Oz Racing GASS RS-As spec’d in black for the project and they’re wrapped in some serious road race tyres in the form of Metzeler’s RaceTec’s, measuring 120/70-17 and a fat 200/55-17 for the rear. Mr K. wanted radial mounted brakes, and that’s exactly what he gets, with all the best bits from Brembo and AC’s own Sunstar built rotors.
And even the bodywork has to serve all of this function, with the front fender made by Sanctuary, and designed to bolt to a radial brake style lower leg, but still have the right look for a GPZ. The same is true of the distinctive front cowl, all customised to suit the exacting specs of the handlebars, which are at a height perfect for the rider. “The front area of the handlebars has the entire upper cowl lowered by 10mm, and the sides have been shaped to prevent interference between the handlebars and the cowl,” Nakamura-san tells us. The side panels and tail are all customised items based on factory plastics, and the seat and screen might look stock but come from another Sanctuary brand, Nitro Racing.
The fuel tank has been restored to perfection and then the paint scheme which was drawn up at the initial design stage is beautifully laid down, with all of the best period correct graphics. But before the clear coat went on, Mr K. wanted to honour Chiparu’s input into the project. So, being the man he is, Nakamura-san had the tank and an oil-based marker pen couriered to the starlet, she signed the tank, and then it was immediately couriered back and cleared before any imperfections could form. By the time this was done, the custom dash was ready to go on, featuring all the goodies like a Stack fuel meter & water temperature gauge, a one-off Yoshimura digital temp meter and a Progress 2 Protec Shift indicator.
The final part of the build was to bolt the engine in, which has been beautifully massaged in the part of the shop dedicated to making horsepower. This part of the company is called DiNx, and from the custom crankshaft to the machined cylinder heads and the bored and honed block, it’s all done in-house with their own products made on-site. Part of the machining was to over-bore the cylinders and the high-end pistons ensure a new displacement of 958cc.
The head is given a workover for increased flow and sucks on a set of Yoshi carbs before spitting spent gases out of a full titanium exhaust system. There is modern electronic ignition, but Nakamura-san ensures the indicators and lights are all classic items. It’s customer service at its best, delivering a beast of a bike and given a unique touch thanks to a social media star.
[ AC Sanctuary ]