S&M Bikes American BB Kit 19mm Bottom Bracket

Product Overview

The S&M American BB Kit is a sealed bearing bottom bracket designed for frames with 2.25" OD American/Mid bottom bracket shells and 19mm spindle cranks. This USA-made kit uses CNC-machined aluminum cups and sealed cartridge bearings to provide smooth, low-maintenance performance. It's ideal for retro builds, re-pop frames, and any BMX or cruiser frame that uses the original American bottom bracket standard.

Key Features

• CNC-machined 6061 aluminum cups – Precision-made for accurate bearing alignment and long-term durability under hard riding conditions
• Sealed cartridge bearings (R12-2RS) – Keep contaminants out and reduce maintenance while maintaining smooth crank rotation through impacts and weather
• 19mm spindle compatibility – Works with standard 19mm two-piece and three-piece crank systems
• Zinc-plated center spacer – 1.93" (49mm) wide spacer correctly positions bearings in standard 2.64" (67mm) American BB shells
• Made in USA – Manufactured domestically with quality control standards and laser engraving on each cup

Technical Specifications

• Bottom bracket type: American/Mid (2.25" OD shell)
• Bearing type: Sealed cartridge (R12-2RS)
• Spindle size: 19mm
• Cup material: 6061 aluminum, CNC-machined
• Spacer material: Zinc-plated steel
• Spacer width: 1.93" (49mm)
• Shell width compatibility: 2.64" (67mm)
• Includes: 2 aluminum cups, 2 sealed bearings, 1 center spacer

Compatibility and Ideal Use Cases

This bottom bracket fits any frame with a 2.25" outer diameter American/Mid bottom bracket shell and works with all 19mm spindle cranks (two-piece or three-piece). It's particularly well-suited for 1980s and 1990s BMX builds, modern re-pop frames using the American standard, and cruiser bikes with American BB shells. The sealed bearing design makes it reliable for street, park, dirt, and flatland riding where low maintenance and consistent performance are priorities.