Shimano UN55 Square Taper Bottom Bracket

• 25% more durable than UN54 with alloy left hand cup
• Traditional square JIS 2-degree taper crank-arm interface
• Offered in either English (BC1.37 x 24tpi - RH/LH) or Italian (M36 x 24tpi - RH/RH) threads

• A good quality bottom bracket for traditional chainsets
• Super-accurate bearings for smooth operation and improved durability
• Durable, hard-wearing sealed cartridge bottom bracket with square tapered spindle fitting
• Lightweight hollow spindle
• Maintenance-free sealed cartridge bearing assembly keeps out dirt, mud, and water for long bearing life
• Fast and easy installation without adjustment
• Narrow body allows clearance for cable routing under the bottom bracket