Maximize linear cutting speed and optimize chain delivery on your mid-range chainsaw with the genuine OEM STIHL .325" 8-Tooth Rim Sprocket System. Tailored precisely for high-demand property maintenance and utility saws under part number 1123 007 1031, this premium system upgrades or restores your clutch drum architecture. It drops seamlessly into legacy platforms like the 021, 023, and 025, as well as modern MS 210, MS 230, and MS 250 saws—including specialized C-BE and C-B quick-tensioning powerheads. Converting to a floating rim allows the drive links to auto-align flawlessly with the guide bar's center track, immediately mitigating rail friction and premature tie-strap wear.
The core advantage of this original equipment manufacturer layout lies in its cost-effective maintenance path and increased velocity. By moving from a standard 7-tooth profile to an 8-tooth configuration, you increase the circumference of the drive hub, instantly boosting linear chain feet-per-minute for faster cutting in light limbs and wood processing. Additionally, when the rim teeth eventually wear down, you simply slide a standalone replacement rim onto the splined hub rather than discarding the entire structural drum assembly, saving long-term maintenance overhead.
True OEM Engineering vs. Soft Aftermarket Metal: High-speed 2-stroke cutting cycles subject the clutch hub to severe thermal stress and impact loads. Substandard aftermarket drive drums are notorious for accelerated spline galling, un-hardened teeth that hook drive links within a few operating hours, and imprecise needle bearing fitment. A genuine STIHL drive cluster guarantees precise boring tolerances for your crankshaft's needle cage, eliminating harmonic vibrations to protect your internal clutch shoes and stabilize oil pump engagement at high RPMs.
Configuration & Pitch Verification Note: This setup is designed specifically for chainsaws running a .325" pitch chain configuration. It will not accept standard 3/8" full-profile or 3/8" Picco (Low Profile) chain. The complete factory service package includes the genuine splined clutch drum shell and the specialized 8-tooth .325" pitch replacement rim element.
Key Features & Benefits
- High-Velocity 8-Tooth Profile: Increases linear chain speed across the guide bar to accelerate high-production limbing, brush clearing, and firewood bucking.
- Floating Rim Self-Alignment: The replaceable rim floats freely across the splines to align perfectly with the bar groove, drastically reducing chain chassis friction.
- Economic Wear Component Paths: Eliminates the need to buy complete replacement drums; simply swap out the inner 8T rim once the wear depth marks are reached.
- 100% Genuine OEM STIHL Manufacture: Crafted from case-hardened high-carbon steel to ensure maximum wear resistance against demanding cutting loads.
- Reduced Chain Derailment & Stretch: Optimized radial geometry guides the chassis drive links smoothly over the hub, dampening high-speed chain slap.
- Comprehensive Handle & Clutch Compatibility: Engineered to fit standard clutches as well as specialized C-variant models featuring premium auxiliary starting systems.
Technical Specifications & System Components
| Brand / Component Tier | STIHL® Genuine OEM Industrial Chainsaw Power Delivery Component |
| Factory Kit Part Number / SKU | 1123 007 1031 (Replaces 1123-007-1031) |
| Chain Pitch Compatibility | .325" Standard Pitch Chainsaw Chain Loops Exclusively |
| Sprocket Configuration | 8-Tooth (8T) Floating Splined Rim |
| Drive Hardware Style | Internal Floating Spline Rim System (Replaces Fixed Spur Drums) |
| Fitment Matrix (Classic Saws) | STIHL 021, 023, 025 Gas Chainsaws |
| Fitment Matrix (Modern Saws) | STIHL MS 210, MS 210 C-BE, MS 230, MS 230 C-BE, MS 250, MS 250 C-B, MS 250 C-BE |
| Material Composition | Heat-Treated, High-Carbon Anti-Friction Steel Alloy |
