External English (BSA) threaded bottom bracket for 73mm shells. Wheels Mfg uses only Enduro bearings and silicone seals for the most durable and smoothest bottom brackets available. Fully serviceable. Includes: (2) - Enduro Silicone dust seals (1) - 2.5mm aluminum BB cup spacers for use with 68mm wide BB shell (1) - 1.8mm aluminum BB cup spacers for use with 68mm wide BB shell (1) - 0.7mm aluminum BB cup spacers for use with 68mm wide BB shell (2) - 0.5mm crank spindle spacers (2) - 1.0mm crank spindle spacers (1) - Wave Washer Direct replacement for SRAM/Truvativ GXP bottom brackets! - Bearings: Enduro ABEC-3 - Color: Red - Bottom Bracket/Frame Interface: ISO/English or BSA Threaded (1.37 in x 24 TPI) - Bottom Bracket Shell Width (mm): 68-73mm - Bottom Bracket Shell I.D.: 33.6-33.9 mm - Crank Spindle Type: GXP (SRAM, Truvativ, Etc.) - Crank Spindle Diameter: 22/24mm - Weight: 116g

- With plastic washers - Shell: 8mm Allen head axle bolt

- One-piece bottom bracket cup set - Bearings included - Fits smaller american juvenile/youth sized BB - Shell: 65mm - Cup Material: Steel - Weight: 173 grams

Shimano's BB-UN55 Square Spindle Bottom Brackets are the unofficial standard for English-threaded cartridge bottom brackets. Quality, value, and durability come together to keep you cranking for many, many miles. - Fits JIS Square-Taper Cranksets - Hollow spindle - Crankarm fixing bolts not included

- Compatible with both American and Mid style BB shells - 6061-T6 full CNC alloy construction - Anodized surface finish - Weight: 255g - Cup Type: Press Fit - Cup OD/Bearing OD: 41mm or 51mm