BOX TWO FIXED SEAT CLAMP 31.8MM

Product Overview

The Box Two Fixed Seat Clamp is a cold-forged aluminum seat clamp designed to secure the seatpost in BMX frames with 31.8mm seat tube diameter. Machined from 6061-T6 aluminum with chromoly hardware, this clamp provides reliable seatpost retention with a clean, durable finish.

Key Features

• Cold-forged construction – Cold-forging process increases material density and strength compared to standard machining or casting
• 6061-T6 aluminum – Heat-treated aluminum alloy provides strength while keeping weight low
• Chromoly hardware – Steel bolt and hardware resist stripping and provide secure clamping force
• Machined frame – CNC-machined clamp body ensures consistent fit and finish
• Anodized finish – Anodizing protects against corrosion and wear while providing color options
• Laser-etched graphics – Permanent laser-etched branding won't fade or peel over time

Technical Specifications

• Material: 6061-T6 aluminum, cold-forged
• Clamp size: 31.8mm (seat tube outer diameter)
• Clamp type: Standard round
• Hardware: Chromoly bolt
• Finish: Anodized with laser-etched graphics

Compatibility and Ideal Use Cases

This seat clamp fits BMX frames with 31.8mm seat tube outer diameter. Measure your frame's seat tube diameter before ordering—seat clamp size must match the frame's seat tube, not the seatpost diameter. The standard round clamp design works with traditional round seat tubes, not integrated or hidden seat clamp systems.

Best suited for riders building or maintaining BMX bikes who need a reliable, lightweight seat clamp. The cold-forged construction and chromoly hardware provide consistent clamping force to prevent seatpost slippage during riding. The anodized finish resists corrosion from weather exposure and sweat. Ideal for park, street, racing, or dirt jumping applications where seat height adjustment is needed. Install with appropriate torque—overtightening can damage the frame's seat tube or crack the clamp, while undertightening allows the seatpost to slip. Check tightness periodically, especially after initial installation or if the seat moves during riding.