3/8" Large Rim Sprocket 8-Tooth – LN22273
Dimensions: OD 45mm | ID 22.5mm | Thickness 9.25mm
Professional quality 3/8" pitch 8-tooth chainsaw rim sprocket designed for chainsaws using a Standard 7 Spline (SD7) clutch drum system.
Manufactured from tough, wear-resistant hardened steel for exceptional durability and reliable power transfer from the chainsaw engine to the saw chain.
The floating rim sprocket design allows the chain to naturally align with the guide bar, helping provide smooth chain operation and even wear across the chain, sprocket and guide bar.
The 8-tooth configuration increases chain speed compared with a standard 7-tooth rim sprocket, making it a popular choice for higher-powered chainsaws used in professional forestry, chainsaw milling, firewood processing and production cutting.
PRODUCT DETAILS
✅3/8" Pitch Rim sprocket
✅8-Tooth Configuration
✅Standard 7 Spline Fitment
✅Wear Resistant Hardened Steel
✅Smoother cutting performance
✅Reduced Chain & Bar Wear
✅Increased Chain Speed
✅Professional Forestry Grade Performance
✅Easy Replacement Design
OEM CROSS REFERENCES
• Oregon 22273
• Carlton SRA18
• GB GBA8L7
COMMON CHAINSAW FITMENTS
Suitable for selected chainsaws using a 3/8" pitch Standard 7 Spline (SD7) rim drive system.
Common applications include selected models from:
• STIHL
• HUSQVARNA
• JONSERED
• DOLMAR
• ECHO
• HOMELITE
• PARTNER
• MAKITA
Selected model applications include:
• STIHL 050
• STIHL 051
• STIHL 075
• STIHL 076
• HUSQVARNA 77
• HUSQVARNA 390XP
• HUSQVARNA 575XPG
• HUSQVARNA 576XP / 576XPG
• JONSERED 2065
• JONSERED 2071
• JONSERED 820
• JONSERED 830
• JONSERED 910
• JONSERED 920
• JONSERED 930
• JONSERED CS2165
• JONSERED CS2171
• JONSERED CS2172
• JONSERED CS2188
• DOLMAR 122
• DOLMAR 123
• DOLMAR 133
• DOLMAR 143
Plus many other chainsaws fitted with a compatible 3/8" Standard 7 Spline rim drive system.
WHY CHOOSE AN 8-TOOTH RIM SPROCKET?
Moving from a 7-tooth to an 8-tooth rim sprocket increases the distance the chain travels with each revolution of the clutch drum, resulting in increased chain speed.
On a sufficiently powerful chainsaw, the higher chain speed can provide faster cutting performance and is particularly useful for professional cutting and chainsaw milling applications.
The trade-off is that an 8-tooth sprocket requires more power from the saw than a 7-tooth sprocket. For smaller or lower-powered chainsaws, the original 7-tooth configuration may provide better cutting torque.
WHY REPLACE YOUR CHAINSAW RIM SPROCKET?
The rim sprocket is a wear component and should be inspected regularly.
As a sprocket wears, grooves can develop where the chain drive links contact the rim. Excessive sprocket wear can contribute to poor chain engagement, increased vibration and premature wear of your saw chain and guide bar.
Replacing a worn rim sprocket helps maintain:
✅ Smooth chain operation
✅ Correct chain engagement
✅ Even chain and bar wear
✅ Reliable power transfer
✅ Maximum life from your saw chain and guide bar
The replaceable rim design also allows the rim itself to be changed without replacing the complete clutch drum, provided the existing drum remains serviceable.
7 TOOTH OR 8 TOOTH?
A 7-tooth rim sprocket generally provides a good balance of chain speed and cutting torque and is the standard configuration on many chainsaws.
An 8-tooth rim sprocket provides increased chain speed but places greater load on the engine.
For this reason, 8-tooth sprockets are generally best suited to larger, higher-powered chainsaws where sufficient engine power is available to take advantage of the increased chain speed.
IMPORTANT FITMENT INFORMATION
Chainsaw models can have different clutch drums, spline sizes and sprocket configurations depending on the model, year and previous modifications.
Before ordering, always check your existing sprocket and confirm:
• Pitch – 3/8"
• Tooth Count – 8 Tooth
• Spline – Standard 7 Spline (SD7)
• Outside Diameter – 45mm
• Inside Diameter – 22.5mm
• Thickness – 9.25mm
If you're unsure whether this rim sprocket suits your chainsaw, contact Longer Chainsaws with your chainsaw make and model before ordering.