Box Two Square Taper Cromo Bottom Bracket

Product Overview

The Box Two Square Taper Cromo Bottom Bracket is a sealed cartridge system built for three-piece cranksets using square taper spindles. Hand-assembled with a chromoly spindle and sealed bearings, it delivers reliable performance at an accessible price point. Designed for young racers and riders seeking durability without premium costs.

Key Features

• Chromoly spindle — Steel alloy provides superior strength-to-weight compared to aluminum, resisting bending under load and lateral impacts
• Sealed bearings — Cartridge design keeps contaminants out, extending service life and reducing maintenance frequency
• Forged and CNC-machined alloy cups — Precision manufacturing ensures consistent bearing seat and reduces play or wobble
• Composite center spacer/seal — Lightweight sealing element protects bearing internals while minimizing weight
• Hand-assembled construction — Individual assembly allows quality control and proper bearing preload tuning

Technical Specifications

• Spindle material: Chromoly steel
• Cup material: Forged and CNC-machined alloy
• Bearing type: Sealed cartridge
• Spindle type: Square taper
• Available widths: 113mm or 118mm
• Spacer/seal: Composite construction
• Assembly method: Hand-assembled

Compatibility and Ideal Use Cases

Fits all BMX frames with standard square taper bottom bracket shells (68mm BSA thread). Compatible with any three-piece crankset using square taper spindles. Best suited for entry-level to intermediate racers, young riders, and those building budget-conscious complete bikes. Recommended for street, park, and racing where sealed protection and cartridge simplicity are valued over lightweight materials.