Sitta GP Aluminium Rear Sprocket for Marchesini, OZ & BST – SuperHard Black, 37–47 Teeth, 520 Pitch (201H-HR20GP)

Engineered to meet the exacting standards of track and high-performance road use, the Sitta GP Aluminium rear sprocket 201H-HR20GP brings the brand's revised HR20GP design together with a proprietary SuperHard anodised coating — delivering measurably longer service life without adding a gram of unnecessary weight. Available in 37 to 47 teeth options on a 520 pitch, this sprocket lets you dial in your gearing with precision for any circuit or road profile.

Key Features

• SuperHard anodised finish dramatically reduces surface wear versus standard anodising, extending sprocket life under sustained hard use on track and road alike.
• CNC-machined from high-grade aluminium, weighing just 320 g in the 45-tooth configuration — a meaningful weight saving over steel equivalents that sharpens throttle response and handling.
• HR20GP revised tooth profile optimises chain engagement across the full rev range, reducing vibration and promoting smooth, efficient power transfer.
• Compatible with Marchesini, OZ and BST rear sprocket carriers using the 76/100 mm, 5-bolt bolt circle — a precise, rattle-free fit straight from the box.
• 520 pitch specification suits the lightweight chain conversions favoured in Superbike, Supersport and serious track-day builds.
• Available in eleven tooth counts from 37 to 47, covering everything from long-circuit top-speed gearing to tight-circuit acceleration ratios.

HR20GP Design & SuperHard Coating

Sitta's HR20GP geometry is the result of ongoing refinement on the racing circuits of Europe. The revised tooth profile maintains consistent chain tension through the engagement arc, reducing the micro-shock loading that gradually degrades lesser sprockets. The SuperHard coating applied over the machined aluminium substrate creates a surface significantly harder than conventional hard anodising, resisting the abrasive action of chain side-plates even under sustained full-throttle acceleration and aggressive downshifts.

The black SuperHard finish is not a cosmetic afterthought — it is the functional layer that sets the 201H-HR20GP apart from standard GP aluminium sprockets. Riders who have previously replaced aluminium sprockets every season will notice a clear extension in service intervals, making this sprocket a cost-effective choice even at its premium price point.

Choosing the Right Tooth Count

Gearing selection has a direct and measurable effect on your motorcycle's acceleration, top speed and engine operating point. Understanding the relationship will help you pick the correct variant for your riding profile.

• Smaller sprockets (37–42 teeth): lengthen the overall gearing ratio, raising top speed and lowering engine revs at cruising and maximum velocity — ideal for fast, flowing circuits and motorway riding.
• Larger sprockets (43–47 teeth): shorten the overall gearing ratio, sharpening acceleration and improving corner-exit drive — the preferred choice for tight technical circuits and urban sport riding.

With eleven tooth options available in the same SuperHard black finish and identical carrier specification, you can re-gear for a different circuit or riding style without changing any other drivetrain component.

Fitment & Compatibility

The Sitta 201H-HR20GP is designed specifically for motorcycles equipped with Marchesini, OZ or BST rear sprocket carriers. The bolt circle is 76/100 mm with a 5-bolt pattern. Chain pitch is 520 exclusively — confirm your chain specification before ordering. This sprocket is not compatible with 525 or 530 pitch chains.

Specifications

• Part number: 201H-HR20GP
• Brand: Sitta
• Material: high-grade aluminium with SuperHard anodised coating
• Pitch: 520
• Available teeth: 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47
• Weight: approx. 320 g (45-tooth)
• Carrier bolt circle: 76/100 mm, 5-bolt
• Compatible carriers: Marchesini, OZ, BST
• Colour: black SuperHard
• Intended use: track and sport road