Bottom Brackets

- 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

- Designed for fat tire bikes - Chromoly spindle - Sealed bearings

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

SRAM's GXP Team PressFit MTB Bottom Bracket Cups are the premium choice for getting the most out of every pedal stroke. They feature smooth bearings that keep drag to a minimum and seals that keep debris out. Plus, these BB cups press directly into the frame without having to be threaded in for reduced weight and enhanced durability.