Building Balance: KAWASAKI Z900RS Custom by SANCTUARY

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SANCTUARY's Z900RS

AC Sanctuary is a shop which creates complete customs that they call RCMs (Radical Construction Manufacture). Their parent company, Noblest, develops and sells many parts including parts under the Nitro Racing and Sculpture brands. This Z900RS, which bears the serial number RCM-632, was completely built by AC Sanctuary and is the latest demo bike for Noblest's Z900RS parts.

"The Z900RS is a current naked bike, but we look at it as a "modern water-cooled Z". Our main focus is to achieve the right overall balance through customization. We don't perform major surgery like we do with air-cooled Zs or Ninjas, but we aim for customization of the hardware rather than decoration, including in the parts we choose, while enhancing the complete RCM feel,” says Mr. Nakamura, representative of Sanctuary/Noblest.

The "Z900RS Ohlins Inverted ExM Package" which allows Ohlins Inverted Forks to be bolted on, Sculpture Bolt-on Wide Swingarm, Nitro Racing Down Tube Kit, Rearsets Kit, 4-in-1 Weld Craft Titanium 3D Exhaust, and Round Type Wide Radiator Kit, as well as OZ Racing GASS RS-A Forged Aluminum Wheels are all parts that have been used in Sanctuary's "first phase" of Z900RS customization. Now, the first part released for "Phase 2" (as of spring 2024), the Nitro Racing Z900RS Subframe for Down Tube is garnering a lot of attention.

"Noblest parts are created through in-house planning, 3D drawing, and prototyping. The next step is to test install the parts, make adjustments, and then put them on the market, and we always design them with functionality in mind. This subframe is designed to connect the front and rear engine mounts, increasing the rigidity of the mounts and the frame. But if it gets too hard the bike can be difficult to handle and it can lead to rider fatigue, so we've raised it just the right amount to avoid these disadvantages. For the swingarm, though there is no problem with its performance, we added a sway bar on the lower side to adjust the overall volume in terms of looks. The ExM package uses a stem to improve the bike's posture, but we are thinking of adding a front fork spring rate change to this package as well. We still have more ideas for parts, so we will continue to work on them," says Nakamura.

The construction reflects the unique RCM style that enhances the overall feel of the Z900RS. It also serves as a reference for how to use each part and how to put them all together.

Handle

The stock 28.6mm bar was replaced with a 22.2mm Daytona RCM Concept Low Handlebar with a new handlebar mount. The front master cylinder is Brembo Racing combined with a ZETA RCM Concept Flight Lever. The Z900RS Billet Light Bracket Kit is made by Nitro Racing.

Bodyworks

The seat is Daytona's RCM Concept Cozy Seat (COMP) with seat base and dimpled mesh for the Z900RS/CAFE/SE. The front side is lowered by 15mm for better footing.

Engine

The Nitro Racing Subframe for Down Tube which wraps around the upper side of the cylinder head was developed as an option exclusively for the Down Tube Kit. It is designed to increase the rigidity of the entire bike.

The engine is stock with a Nitro Racing Reduction Kit (frame slider) added. The cooling system is reinforced with a Round Type Wide Radiator Kit and a Wide Radiator Special Core Guard.

Chassis

The Rearsets Kit (Silver) is by Nitro Racing. It can also be installed stand-alone. The drive chain is an EK ThreeD 525Z BK;GP (black and gold), which conforms to the stock size.

Ohlins FGRT207 forks are installed with Noblest's "Z900RS Ohlins Inverted ExM Package". The front disc is SUNSTAR's Works Expand for OZ Racing Wheels without Attachments which can be directly mounted on large-hub OZ Racing forged wheels without an adapter. The discs suppress the escape of braking force for good braking power and touch. The radial-mounted 4-piston calipers are Brembo 484 cafe racer.

The CNC 2-piston rear caliper is a Brembo GP2-SS set with the Brembo 2POT Rear Caliper Support Kit and combined with a SUNSTAR Premium Racing Disc. The exhaust system is Nitro Racing's Z900RS 4in1 Weld Craft Titanium 3D EX Exhaust + Valiant Silencer.

A block sway bar is added to the underside of the Sculpture Bolt-on Wide Swingarm. The inner fender is Nitro Racing's Carbon Inner Fender Kit which can be installed on either the Sculpture or stock swingarm. The wheels are OZ Racing GASS RS-A Forged Aluminum with 3.50-17/6.00-17 sizes.

Gallery

Specifications

Part	Details
Engine	NITRO RACING Round Type Wide Radiator Kit NITRO RACING Round Wide Radiator Core Guard
Exhaust	NITRO RACING 4-in-1 Weld Craft Titanium 3D Exhaust System
Frame	NITRO RACING Down Tube Kit NITRO RACING Subframe Kit for Down Tube SCULPTURE Wide Swingarm Kit
Brake	brembo Racing Radial Brake Master Cylinder (19 x 18) brembo 484 Cafe Racer Caliper SUNSTAR Works Expand φ320 Disc for OZ Racing Wheel without Attachment ALLEGRI Short System Brake Hose/Banjo brembo GP2-SS CNC 2P Rear Caliper NITRO RACING brembo 2POT Rear Caliper Support Kit SUNSTAR WORKS EXPAND Rear Floating Disc Rotor
Wheels	OZ Racing GASS RS-A Forged Aluminum Wheels
Suspension	OHLINS FGRT207 OHLINS Rear Suspension NITRO RACING Ohlins Rear Suspension Preload Adjuster Bracket
Steps	NITRO RACING Rearsets
Drive System	EK ThreeD 525Z BK;GP Drive Chain
Handle / Steering	SCULPTURE Stem Kit DAYTONA RCM Concept Low Handlebar NITRO RACING Billet Light Bracket Kit Magical Racing NK1 Mirror TYPE-4 KOHKEN (KOHKEN DENKA) Mechanical Clutch Holder SANCTUARY [ZETA x RCM] RCM Concept Flight Lever
Seat	DAYTONA [DAYTONA x AC SANCTUARY] RCM Concept COZY Seat [COMP]
Bodyworks	NITRO RACING Carbon Front Fender NITRO RACING Carbon Inner Fender Kit NITRO RACING Rear Fender Eliminator Kit

About SANCTUARY

SANCTUARY is a custom builder that is good at Vintage motorcycles like Z1,Ninja and KATANA. They sell special parts which were born from trial and error that mechanics had repeated mounting and testing

SANCTUARY brand page

Original Source of this Article

Heritage & Legends