Bottom Brackets

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

- Simple and reliable square taper bottom bracket - Replaces both BB-UN26 and BB-UN55 - Sealed cartridge bearings - Cr-Mo axle - For bicycles equipped with a chain case, select BB-UN300-K - For E-type front derailleur compatibility, choose BB-UN300-E - Fixing bolts not included; Shimano FC-E6000 bolts suggested

- Simple and reliable square taper bottom bracket - Replaces both BB-UN26 and BB-UN55 - Sealed cartridge bearings - Cr-Mo axle - For bicycles equipped with a chain case, select BB-UN300-K - For E-type front derailleur compatibility, choose BB-UN300-E - Fixing bolts not included; Shimano FC-E6000 bolts suggested

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

The SRAM DUB bottom bracket series has a simple job— to connect crankarms and protect the smooth, long-lasting application of power to the drivetrain. SRAM engineered the oversized DUB spindle to work across every bottom bracket standard, simplifying crankarm compatibility. - Gutter Seal Technology drastically improves sealing against the elements - Sealed cartridge bearings - One oversized spindle to work across every bottom bracket standard - Significantly lighter than GXP system