RDLN Racing Clutch Kit w/ Adjustable Sheave Pulley - 139QMB

Upgrade your entire rear CVT driven assembly with the RDLN Racing Clutch Kit with Adjustable Sheave Pulley (1200-1275) for 139QMB and GY6 50cc engines. This complete kit replaces the stock clutch with a performance-engineered unit designed for rapid, reliable engagement and customizable acceleration tuning.

Includes three components: the clutch shoe assembly with red reinforced friction plates and 1500rpm engagement springs; the red anodized vented clutch bell/drum with large tapered vents and splined center bore; and the adjustable six-groove sheave pulley (three straight ramps for quicker off-the-line takeoff, three curved ramps for higher top speed). Cross-drilled holes and tapered vents on the outer drive face enhance heat dissipation under hard use.

This product is intended for off-road use only. This product is not intended for use on public roads or land.

Technical Specifications

• Clutch Spring Tension: 1500rpm engagement
• Clutch Bell Inner Diameter: 107mm
• Clutch Bell Outer Diameter: 117mm
• Clutch Bell Splines: 22 splines, 11.2mm inner diameter (peak to peak)
• Clutch Shoe Inner Diameter: 24mm (flat to flat) / 28mm (round to round)
• Clutch Shoe Outer Diameter: 105mm
• Clutch Shoe Height: 30mm
• Sheave Outer Diameter: 118mm
• Sheave Ramp Grooves: 6 total — 3 straight (quick takeoff) + 3 curved (top speed)
• Includes: Clutch shoe assembly, vented clutch bell/drum, adjustable sheave pulley
• Origin: Taiwan
• SKU: 1200-1275

Compatibility — 139QMB-Based Engine Codes

If your 50cc–100cc engine code contains "QM" or "FM" it is likely compatible with this kit.

• Complete Kit: Clutch Shoe Assembly + Red Vented Clutch Bell/Drum + Adjustable Sheave Pulley
• 1500rpm Engagement Springs with Red Reinforced Friction Plates for Rapid Reliable Clutch Engagement
• Red Anodized Vented Clutch Bell with Large Tapered Vents and Splined Center Bore
• Adjustable 6-Groove Sheave: 3 Straight Ramps for Quicker Takeoff + 3 Curved Ramps for Higher Top Speed
• Cross-Drilled Holes and Tapered Vents on Outer Drive Face for Enhanced Heat Dissipation

SKU: 1200-1275 | Brand: RDLN | Spring Tension: 1500rpm | Bell ID: 107mm | Bell OD: 117mm | Bell Splines: 22 (11.2mm ID peak to peak) | Shoe ID: 24mm flat/28mm round | Shoe OD: 105mm | Shoe Height: 30mm | Sheave OD: 118mm | Sheave Ramps: 6 (3 straight + 3 curved) | Includes: Clutch shoe assembly, vented bell/drum, adjustable sheave pulley | Origin: Taiwan | Use: Off-road only

139QMA | 139QMB | 1P39QMB | 1P39QMA-2 | YN139QMB | JJ1P39QMB | 139FMA-2 | BD1P39QMB | BN139QMB | 147QMD | Other QMA/QMB/FM engine code variants (50cc GY6)