Bottom Brackets

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

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

- Forged steel body - Alloy cups - Chromoly spindle - Sealed bearings - Interface: English - Spindle Type: Square Taper JIS - Weight: 290-300 grams

- Steel body - Steel cups - Chromoly spindle - Sealed bearings - Interface: English - Square Taper JIS - Weight: 305-320 grams

- Replacement fat bike bottom bracket with square-taper chromoly spindle - Sealed bearings - Steel shell and cups - 120mm shell width - 180mm spindle length - 1.37" x 24T English thread

- Bottom bracket for one-piece crank - Sealed mechanism - 24 TPI - Spindle Type: One piece - Cup Material: Steel - Weight: 310-315g - Cup Type: Press Fit - Cup OD/Bearing OD: 51mm

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

Forged and CNC machined AL6061 cups - Double sealed replaceable bearings - Fits 68mm and 73mm shell widths - 1.37" x 24T English thread - Alloy spacers included for chainline adjustment - Anodized and laser etched finish

- Standard JIS square taper with steel cups, retainers, lockrings, CrMo spindle, shield included - Formerly called CBB-ST, renamed CBBF

- 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