Upgrade your mid-range chainsaw from a fixed spur setup to a professional-grade drive system with the genuine OEM STIHL 3/8" Picco 7-Tooth Rim Sprocket System. Purpose-built to optimize cutting alignment on legendary STIHL platforms like the 021, 023, and 025, as well as modern MS 210, MS 211, MS 230, and MS 250 models, this floating-rim configuration represents a major performance leap. Unlike standard welded spur drums that force you to replace the entire clutch assembly when the teeth wear down, this system allows you to slide on a fresh, inexpensive replacement rim in seconds right at your workbench.
The core advantage of this genuine factory upgrade is its floating-rim architecture. The 7-tooth Picco (Low Profile) rim slides freely along a splined clutch hub, automatically self-aligning the drive links of your saw chain perfectly with the absolute center of your guide bar's entry groove. By eliminating the forced side-loading and lateral slap common with worn spur sprockets, this system dramatically slashes friction, smooths out engine vibration, and eliminates premature wear on your guide bar rails and drive links. It maximizes every ounce of engine torque, providing smoother bore cuts and flatter cutting profiles under heavy timber loads.
True OEM Steel Metallurgy vs. Soft Aftermarket Clones: The drive sprocket is subjected to intense centrifugal force and abrasive wood grit at speeds exceeding 12,000 RPM. Substandard aftermarket sprocket kits routinely suffer from rapid tooth pocket deformation, which causes chain binding, erratic throwing, and dangerous tension spikes. Genuine STIHL drive components are case-hardened using specialized proprietary steel alloys to guarantee flawless splined concentricity, uniform tooth depth, and an exact match to genuine STIHL Picco™ 3/8" low-profile saw chain geometry.
Fitment & Pitch Verification Note: This genuine conversion kit is optimized exclusively for STIHL models configured with a 3/8" Picco / Low Profile (LP) pitch bar and chain setup. It does not fit .325" or standard 3/8" professional pitch setups. Please confirm your guide bar stamping matches 3/8" Picco / .050" or .043" gauge configurations before upgrading.
Key Features & Benefits
- Floating Rim Architecture: Rim shifts laterally along the splined clutch drum, self-aligning the chain with the guide bar groove to minimize operational friction.
- 100% Genuine OEM STIHL Production: Manufactured using case-hardened, industrial-grade steel alloys for precise radial balance and exceptional resistance to pocket wear.
- Cost-Efficient Field Servicing: Eliminates the need to buy complete replacement drums; simply swap the worn 7-tooth rim element to refresh your drive line.
- Broad Legacy & Modern Compatibility: Drop-in dimensional optimization for classic 021, 023, and 025 models, plus modern MS 210, MS 211, MS 230, and MS 250 powerheads.
- Enhanced Cutting Velocity & Comfort: Reduces operational chassis vibration and chain drag to deliver cleaner cuts while shielding the crankshaft from shock.
- Perfect 3/8" Picco Tracking: Precision tooth profiling prevents micro-slippage, ensuring flawless engagement with both .043" and .050" gauge low-profile chains.
Technical Specifications & System Components
| Brand / Component Tier | STIHL® Genuine OEM Chainsaw Powertrain Conversion Component |
| Replacement Rim Part Number (MPN) | 0000 642 1240 (3/8" Picco 7T Floating Rim) |
| Chainsaw System Pitch | 3/8" Picco / Low Profile (LP) |
| Drive Tooth Profile | 7-Tooth Configuration (P-7) |
| Full Powertrain Model Fitment | STIHL 021, 023, 025, MS 210, MS 210 C, MS 211, MS 211 C, MS 230, MS 230 C, MS 250, MS 250 C |
| Spline Configuration Size | Mini-Spline Drive Interface Hub |
| Compatible Chain Gauges | Fits both .043" (Mini) and .050" Picco Micro/Super Saw Chains |
| Application Profile | Landowner Firewood Production, Residential Limbing, and Utility Ground Clearing |