Box One Stem Spacers 1"

Product Overview

Box One stem spacers are precision-machined aluminum spacers designed to adjust headset height and stem positioning on BMX bikes with 1" steerer tubes. This five-piece kit provides flexible spacing adjustments from 1mm to 10mm individually, or up to 20mm when combined, allowing you to fine-tune your cockpit geometry without replacing your entire stem. Whether you're dialing in bar rise for comfort, clearing cable routing, matching a new fork install, or optimizing your riding position, these spacers give you the adjustment range needed for proper headset setup and geometry changes.

Key Features

• 6061-T6 aluminum construction – Extruded and CNC-machined for consistent tolerances, durability, and corrosion resistance over time
• Ultra-minimalist design – Removes unnecessary material while maintaining structural integrity and load-bearing capacity under stress
• Lightweight – Individual spacers weigh only 0.02–0.14 oz (0.56–4g) depending on thickness, keeping total cockpit weight minimal and responsive
• Five-piece mixed kit – Includes (2) 1mm, (1) 3mm, (1) 5mm, and (1) 10mm spacers for comprehensive adjustment flexibility across most setup scenarios
• Stacking compatibility – Spacers can be combined in any configuration to achieve any total height between 1mm and 20mm total adjustment
• Precise CNC machining – Tight tolerances ensure smooth integration with your headset and stem clamp without binding, play, or resistance

Technical Specifications

• Steerer tube size: 1" (standard integrated or threaded headsets)
• Material: 6061-T6 aluminum alloy
• Included spacers: (2) 1mm, (1) 3mm, (1) 5mm, (1) 10mm
• Individual weights: 0.02–0.14 oz per spacer (0.56–4g depending on size)
• Maximum combined adjustment: 20mm total height
• Type: Headset spacers
• Quantity: 5 pieces per pack

Compatibility & Ideal Use Cases

These spacers fit 1" steerer tubes found on BMX bikes with standard integrated or threaded headsets. They're essential for fine-tuning stem height during initial bike setup, fork replacements, or geometry adjustments. Use them to raise or lower your bars for comfort and control, clear brake and cable routing, or dial in the exact cockpit position that matches your riding style and bike geometry. Compatible with any 1" headset system and standard stem clamps.