Box Four Prime 9 Rear Derailleur
Best budget upgrade for simplifying entry-level mountain bike drivetrains.
This derailleur offers a simple, lightweight, and affordable 1x8-speed clutch system, making it a great upgrade for entry-level bikes. It provides a more durable and user-friendly alternative to traditional 3x drivetrains.
$64.99
at
g.h.y Bikes
More Prime 9 options
Who it's for
- Aggressive riders needing a drivetrain that survives rough trail abuse
- Mountain bikers wanting quiet, secure chain retention on technical descents
- Budget-conscious riders seeking wide-range gearing without a premium price tag
Who should skip it
- Weight-weenies prioritizing the lightest possible build for their bike
- Performance-focused riders demanding crisp, instantaneous shifting under heavy load
- Road or gravel cyclists requiring tight gear steps for cadence control
Performance breakdown
Drivetrain Simplicity
Eliminating the front derailleur makes shifting intuitive and maintenance significantly easier.
Chain Retention
The integrated clutch mechanism keeps the chain secure over rough terrain.
Installation Ease
Straightforward setup makes this a perfect weekend project for home mechanics.
Durability
Built to withstand daily abuse better than standard entry-level components.
Shift Precision
Reliable indexing that performs consistently across the entire eight-speed range.
Weight Efficiency
Stripped-down design sheds unnecessary bulk compared to traditional triple-chainring setups.
Key Specs
Color
Black
Speeds
8-speed
Cage Length
Short Cage
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Ask Metto anything about the Box Four Prime 9 Rear Derailleur before you decide.