Sitta Aluminium Rear Sprocket for BMW HP4, HP4 Race & S1000RR HP Forged Wheel (204Y) – 37-47 Teeth, 525 Pitch

Keeping your BMW HP4 or HP4 Race running at its best day after day starts with reliable, well-engineered drivetrain components. The Sitta 204Y aluminium rear sprocket delivers exactly that — a precision-machined, lightweight sprocket available in tooth counts from 37 to 47 and eight anodised colour options, letting you dial in the gearing that suits your riding without compromising on durability or fit.

Key Features

• Precision-machined aluminium construction keeps unsprung weight low while offering excellent resistance to wear under sustained load
• Exclusive 525 pitch — engineered specifically for BMW HP Forged Wheel applications on the HP4, HP4 Race and S1000RR HP Schmiederad
• Sprocket carrier specification 70/100-5 hole pattern ensures a direct, rattle-free fit with no modifications required
• Tooth range of 37 to 47 allows genuine gearing flexibility — tune for top speed on long runs or sharper acceleration for technical riding
• Available in eight finishes: silver, black, hard-anodised, red, blue, gold, orange and green — hard-anodised offering notably greater surface hardness than standard anodising
• Consistent manufacturing tolerances mean straightforward installation alongside your existing chain and carrier

Gearing Guide

Choosing the right tooth count has a meaningful effect on how your BMW behaves on the road or track. A smaller sprocket in the 37-to-42 tooth range lowers overall gearing, which reduces engine rpm at motorway speeds and extends the top end — useful for circuits with long straights or for relaxed road touring. Moving to the 43-to-47 tooth range raises the gearing ratio, sharpening initial acceleration and making the bike feel more responsive through tight sections. The Sitta 204Y range lets you make that adjustment without changing your sprocket carrier or chain pitch.

Build Quality & Finish

Sitta machines the 204Y from high-grade aluminium, balancing the need for low mass with genuine structural integrity. The standard anodised finishes — silver, black, red, blue, gold, orange and green — provide good corrosion resistance and a clean appearance that holds up well in road use. The hard-anodised option goes further, producing a surface layer that is significantly harder and more abrasion-resistant, making it the sensible choice if the bike sees heavy track use or high-mileage road riding where chain wear is a constant concern.

Fitment & Compatibility

The Sitta 204Y is designed exclusively for BMW models fitted with the HP Schmiederad (HP Forged Wheel). It is available in 525 pitch only and is not compatible with standard 520 or 530 chain setups. Confirmed fitments:

• BMW HP4 (all years)
• BMW HP4 Race
• BMW S1000RR with HP Schmiederad (HP Forged Wheel)

Sprocket carrier: 70/100-5 hole pattern. Chain pitch: 525 only. Part number: 204Y.

Specifications