BOX TWO CENTER CLAMP STEM 22.2mm 1-1/8"

Product Overview

The Box Two Center Clamp Stem is a hollow, cold-forged 6061-T6 aluminum stem with a dual mid-bolt wedge mounting system and skeletal design. Designed for 1-1/8" steerer tubes and standard 22.2mm handlebars, it weighs 213g (48mm) or 218g (53mm) and features center-positioned mounting bolts that reduce weight and eliminate knee hazard from rear pinch bolts. Meets or exceeds ENBMX Category 1 standards.

Key Features

• Hollow, cold-forged 6061-T6 aluminum – Cold forging increases material density before machining creates a hollow stem body; removes material from the interior to reduce weight while maintaining strength
• Open skeletal design – Material removed from low-stress areas creates an open, lightweight structure without compromising strength
• Dual mid-bolt wedge mounting system – Mounting bolts positioned in the center of the stem rather than the rear; wedge design secures the steerer tube without rear pinch bolts that can contact rider's knees
• Chromoly hardware – High-strength chromoly bolts provide secure clamping force
• Laser-etched graphics – Permanent graphics resist wear and fading compared to printed or anodized logos
• 5-degree rise – Slight upward angle raises handlebar position relative to steerer tube
• ENBMX Category 1 certified – Meets or exceeds European safety standards for BMX use

Technical Specifications

• Material: 6061-T6 aluminum alloy (cold-forged, hollow construction)
• Hardware: Chromoly bolts
• Clamping Type: Front load (center clamp wedge system)
• Steerer Tube Diameter: 1-1/8"
• Handlebar Clamp Diameter: 22.2mm
• Rise: 5°
• Reach Options: 48mm, 53mm
• Weight: 213g (48mm), 218g (53mm)
• Minimum Required Steerer Tube Exposure: 40mm
• Safety Standard: Meets or exceeds ENBMX Category 1

Important Compatibility Note:

• Not compatible with carbon fiber steerer tubes
• Requires minimum 40mm exposed steerer tube length for proper clamping

Compatibility and Ideal Use Cases

This stem is compatible with 1-1/8" aluminum or chromoly steerer tubes with at least 40mm of exposed length above the headset. Not compatible with carbon fiber steerer tubes due to the wedge clamping system. Works with standard 22.2mm BMX handlebars. The center clamp wedge design eliminates rear pinch bolts, reducing stem length and removing a knee contact hazard during crashes or aggressive riding. Ideal for racers who want a lightweight, hollow stem with improved safety from the center-bolt design. The 5-degree rise provides moderate handlebar lift. Choose reach based on rider size—48mm for closer hand positioning, 53mm for extended reach. Note: Ships direct from manufacturer if located in the USA, which may result in separate delivery from other items.