Japanese Custom Culture
POWER BUILDER's Z1-R
The owner of this Z1R has been riding the bike for over 15 years. In those days, he has been around various custom stores and has repeatedly changed specifications. The engine was the first thing that prompted POWER BUILDER to get involved. The engine was tuned appropriately at that stage, but he asked the POWER BUILDER to refine it. Eight years ago, the engine was upgraded to the current specifications. The engine is now 1,166cc with Cosworth pistons, APE camshaft, twin plugs, and the curvature of crankshaft has been adjusted, and the owner is very satisfied with the results. The engine was converted to the current specifications eight years ago, although it has been driven a considerable number of miles in those eight years, it is still powerful enough to wheelie even without an overhaul.
The owner has visited various custom stores over the years to change the chassis, but now leaves it to the POWER BUILDER. However, the owner also wanted to use YSS front and rear shock absorbers, which is a rare configuration for POWER BUILDER. The owner's first reason for choosing YSS was partly because he wanted to change the look of the bike, including the coloring, but of course, POWER BUILDER would never customize a bike just for looks. The reason why the owner had been going from one custom store to another is because he had high objectives for riding performance. The owner's high objectives are embodied in, and the POWER BUILDER's know-how has been fully incorporated into this bike.
Electrical
The tachometer was changed to a Nagai Denshi's Ultra series to improve reliability. The meter looks like the stock meter and does not look out of place, but the installation is said to be a very difficult and time-consuming process.
Engine
The engine was tuned by POWER BUILDER 8 years ago, although it has traveled a considerable distance, it has not been overhauled except for a tappet adjustment. It is still more than enough powerful and wheelie easily.
Intake & Exhaust
The exhaust system is a machine-bent titanium megaphone from POWER BUILDER. The machine-bent exhaust system was chosen to match the atmosphere of old bikes and classic bikes with old tastes, instead of a sleek hand-bent exhaust system. The spiral collector makes it easier to handle.
Chassis
JB Power Magnesium Forged JB3 wheels were chosen for both front and rear. These are POWER BUILDER's most trusted wheels and have been used in many cases. Radial-mounted monoblock brake calipers were selected.
The rear shocks are YSS SII 362, which is also supported by Taste of Tsukuba, and POWER BUILDER's know-how is also incorporated into this machine for high road-following performance.
This unique swingarm was installed by the owner when he was moving from one custom store to another in the past. It was probably made by TRAC, but the length and the rigidity were not a problem, so he continues to use it.
The rear brake also features Nissin 2-pot caliper and Φ260mm rotor for controllable operation. Like the front wheel, JB-Power Magnesium Forged JB3 wheels are 4.50mm, not too wide.
Gallery
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Specifications
| Part | Details |
|---|---|
| Engine | COSWORTH Piston Φ75mm APE 435 Camshaft |
| Carb / Intake | KEIHIN FCRΦ37mm |
| Exhaust | POWER BUILDER Machine Bent Megaphone Exhaust |
| Brake | NISSIN Radial 4Pot Front Brake Caliper NISSIN 2Pot Rear Brake Caliper SUNSTAR Front Brake Disc SUNSTAR Φ260 Rear Brake Disc Brembo Radial Master Cylinder |
| Wheels | JB-POWER Magnesium Forged Wheel JB3 |
| Suspension | YSS KG308R Front Fork YSS Rear Suspension SII362 |
| Steps | MORIWAKI Rearsets Kit |
| Handle / Steering | SCULPTURE Bracket |
| Oil Cooler | EARLS Oil Cooler |
| Electrical | ASUotani SPII Full Power Kit ULTRA Tachometer |
About POWER BUILDER
"POWER BUILDER" is a winning tuner in the Taste of Tsukuba, Japan's premier Sunday race for steel-frame bikes from the 80s and 90s. "Power Builder" is a tuner who always wins the Taste of Tsukuba, the most prestigious Sunday race in Japan, where the best bikes from the 80s and 90s compete. Power Builder" is not a restoration company, but rather a company that creates power, a company that is thoroughly committed to creating products that live up to its name.
