Shimano BB-UN300 Square Tapered Bottom Bracket

The Shimano BB-UN300 bottom bracket delivers reliable performance and long-lasting durability for everyday and performance-focused riding. Featuring a JIS square taper interface, it is designed to work seamlessly with compatible cranksets while maintaining a consistent chain line for smooth and efficient pedaling.

Built for frames with BSA threading and 68 / 73 mm shell widths, the BB-UN300 uses a sealed cartridge bearing design to ensure low maintenance and dependable operation. A hollow steel spindle balances strength and weight, making it a solid choice for road, commuter, and MTB setups.

Key Features

• Compatible with JIS square-taper cranksets

• Sealed cartridge bearing design for durability and smooth rotation

• Stabilizer design helps maintain a consistent chain line

• Hollow spindle for an optimal balance of strength and weight

• Designed for BSA-threaded frames (68 / 73 mm shell width)

Specifications

• Bottom Bracket Type: Cartridge bearing

• Crank Interface: JIS Square Taper

• Frame Compatibility: BSA thread

• Shell Width: 68 / 73 mm

• Spindle Material: Steel

• Adapter Material: Aluminum (left), Aluminum / Steel (right)

• Crankarm Fixing Bolts: Sold separately

Additional Info

• Country of Origin: Malaysia/Japan
• Imported By: Shimano South Asia Pvt Ltd. , 19 , (Ground Floor) Kumara Krupa Road , Bangalore – 560 001 , Karnataka , India.
• Net Quantity: 1N
• Customer Care Address:  Chanduram Road, H No.335, Janta Chowk, Main bazaar, Jaripatka, Nagpur(MH)- 440014 Email: ashamallnagpur@gmail.com
• Commodity: Bottom Brackets