The new 2001 ZRX gets an increase in bore and stroke which takes the donk out to 1,164 cm3. The bigger pistons reciprocate in a new, all-aluminium cylinder with plated bores. Other engine improvements include new cam profiles, improved shift feel and clutch operation, a new crank and a new, all-stainless exhaust system. The new engine pumps out more power across the rev range, with noticeably more punch in the mid-range. 

The big news is a new model added to the line-up, the ZRX1200S, equipped with a half cowl which joins the existing bikini-cowled ZRX1200R.

Chassis improvements start with a larger, stiffer aluminium swingarm; the triangulated construction featuring bracing grooved for added rigidity. Additionally, a relocated swingarm pivot, a wider rear wheel and wider rear tyre, a reduction in fork offset and a host of detail changes.

ZRX1200R – Today they call it World Superbike, but back when the whole show got started it was Eddie Lawson on his bikini-faired Green Monster who power-slid this machine's legendary styling into the record books. 

ZRX1200S – With more and more riders wanting greater versatility from their high performance bikes, the added wind protection and the sleek, sporty look of the S model's half cowl make it the perfect touring partner.

ENGINE
If you didn't know any better, you'd be excused from thinking that bumping up the big ZRX's displacement to 1200 wasn't such a big deal. Just bore it out a bit, stroke it a few mil and slap on some new decals, right? Wrong! The new aluminium cylinder with its bigger bores is wider, necessitating wider cases, a longer crank, a wider head and valve cover, and a whole slew of other new components. 
In point form - 

• Powerful, liquid-cooled, DOHC, In-line 16-valve Four now displaces 1,164 cm3 via an increase in bore and stroke from 76 x 58 to 79 x 59.4 mm. 
• New, plated, all-aluminium cylinder weighs approximately 1.0 kg less than the earlier steel-liner cylinder while offering improved heat dispersion and longer wear. 
• New cylinder head has oil return holes added between the cylinders for quicker, more efficient return of oil. 
• Cam drive sprockets moved 3 mm outboard to compensate for the wider cylinder. Engine cases, cylinder head and cylinder head cover are correspondingly wider, as well. Overall engine width increased by about 5 mm. 
• New cam timing complements the increase in displacement and contributes to increased power and torque across the rpm range. 
• New concave pistons give a highly efficient bi-convex shape to the combustion chamber. 
• New crankshaft with inertia and balancing to suit the increase in displacement and the larger pistons. 
• Four Keihin CVK36 carbs equipped with K-TRIC deliver sharp throttle response at all rpm. 
• Digital electronic ignition delivers hot sparks at the ideal timing. 
• New, double coned disc springs (diaphragm-type) in clutch housing enhance clutch action and make for smoother low-rpm operation and easier shifting of the 5-speed transmission. 
• New, all stainless steel exhaust system (replaces earlier hot-dip aluminium-coated steel unit) reduces corrosion. Balance tubes eliminated from header pipes; muffler angle changed to be parallel to bike centreline. 
• Engine side covers and cylinder head cover finished in bronze colour for improved appearance. 

FRAME / SUSPENSION
The new ZRX has a  stiffer aluminium swingarm with revised pivot location.  It is complemented by a slight reduction in steering offset which quickens up the steering to compensate for the slightly longer wheelbase of the new bike.
In point form - 

• Wheelbase increased by approximately 12 mm due to fitting of a 3-teeth smaller, 42-tooth rear sprocket – use of smaller sprocket possible due to increased torque and power of the new engine. 
• New, braced aluminium swingarm is larger and stiffer, contributing to the ZRX's superbly balanced handling qualities. 
• Swingarm pivot is stronger, and its location is now 5 mm lower for improved rear suspension action, high traction and reduced chain whip during hard acceleration. This change delivers superb traction over a wide range of riding conditions. 
• Rear shocks now mount 15 mm further forward for improved suspension action and increased wheel travel. Shock length remains unchanged, as does their full adjustability. 
• Front fork steering offset reduced from 30 mm to 28 mm. 
• Frame gusset added behind steering head increases frame stiffness. 

Putting the big ZRX's pumped up muscle to the ground is a wider rear tyre mounted on a wider wheel. Taller gearing means less shifting and more enjoyment of the engine's improved torque spread. 

Gigantic 6-piston Tokico calipers bite into semi-floating, radially-drilled 310 mm stainless steel disc rotors. At the rear there is a compact, lightweight 250 mm rear disc brake.  Rear wheel width is increased from 5.0 to 5.5 inches and wider rear tyre (170/60 ZR17 changed to 180/55 ZR17).  Driveline lash is reduced via the use of a ZX-12R-type rear-wheel damper. Ride quality is greatly improved as a result. 

The ZRX1200S is equipped with a half cowl that employs ZX-12R-type dual reflector headlights. New aerodynamic mirrors reduce wind resistance. A new seat with ZX-12R-type seat foam improves ride comfort.  The 'S' also scores complete instrumentation which includes a speedometer, odometer, tripmeter, fuel and water temperature gauges, an oil warning lamp and indicator lamps. 

Bungee hooks at top of rear shocks are now fitted as standard equipment, making it easier than ever to carry luggage.   Inner fork tube guards added to front forks and guards added to inner tubes of rear shocks help prevent rocks from marring the operating surfaces. 

New ZX-9R/6R fuel cap with dual sealing prongs improves fuel cap sealing.   New ZX-12R-type in-tank fuel gauge sensor.   New ignition switch is more tamper resistant. 

Australian Colours for the ZRX1200S is limited to the 'Metallic Phantom Silver and Black Pearl' colour scheme shown in the photos.  In the ZRX1200R we get a 'Black Pearl and Metallic Blue Violet' scheme.

SPECIFICATIONS
ENGINE ZR1200
Type 4-stroke In-Line Four 
Displacement 1,164 cm3 
Bore and Stroke 79 x 59.4 mm 
Valve system DOHC, 16 valves 
Carburation Keihin CVK36 x 4 (K-TRIC) 
Ignition Digital 
Starting Electric 
Cooling Liquid 
Lubrication Forced lubrication, wet sump 
Spark plug CR9EK U27ETR 
Valve timing: Inlet Open: 35° BTDC; Close: 55° ABDC; Duration: 270° 
Exhaust Open: 45° BBDC; Close: 25° ATDC; Duration: 250° 
Exhaust 4-into-1 

DRIVETRAIN 
Transmission 5-speed, return 
Primary drive Gear 
Final drive Chain 
Primary reduction ratio 1.637 (95/58) 
Gear ratios: 
1st 2.733 (41/15) 
2nd 1.947 (37/19) 
3rd 1.478 (34/23) 
4th 1.192 (31/26) 
5th 1.035 (29/28) 
Final reduction ratio 2.470 (42/17) 
Overall drive ratio 4.191 @ top gear 
Clutch Wet, multi-disc 

FRAME 
Type Double cradle 
Suspension: front - 43 mm cartridge fork with 10-way compression, rebound damping and spring preload adjustability 
Suspension: rear - Dual, gas charged shocks, piggy-back reservoir, adjustable spring preload, 4-way compression and rebound damping 
Wheel travel: front 120 mm 
Wheel travel: rear 123 mm 
Tyre: front 120/70 ZR17 (58W) T/L radial 
Tyre: rear 180/55 ZR17 (72W) T/L radial 

BRAKES 
Front Dual semi-floating 310 mm discs 
Front caliper 6-piston calipers 
Rear Single 250 mm disc 
Rear caliper Opposed-piston caliper 

DIMENSIONS 
Overall length 2,120 mm 
Overall width 780 mm 
Overall height ZR1200R:1,150 mm,ZR1200S:1,230 mm
Wheelbase 1,465 mm 
Ground clearance 135 mm 
Seat height 790 mm 
Fuel capacity 19 litres