BB-UN300 Bottom Bracket - Most MTB Double Cranksets

Product Information

The Shimano BB-UN300 bottom bracket is a solid choice for maintaining a smooth and reliable drivetrain on your bike, particularly for many MTB double cranksets. This square taper cartridge bottom bracket offers dependable performance for a wide range of riding, from city commuting to touring, road, and mountain biking. Its sealed bearings ensure a long lifespan and consistent operation.

Designed for durability and easy installation, the BB-UN300 is a versatile component that succeeds older reliable models like the BB-UN26 and BB-UN55. It provides stable chainline performance, making it a trustworthy foundation for your cranks.

Features

• Sealed cartridge bearings for smooth, durable performance.
• Hollow spindle design.
• Engineered for stable chainline with various crankset types.
• Successor to trusted BB-UN26 and BB-UN55 models.

Specs

• Type: Square Taper (JIS)
• Shell Width: 68mm, 73mm (BSA Threaded)
• Spindle Lengths: Available in various lengths including 107mm, 110mm, 113mm, 115mm, 117.5mm, 118mm, 122.5mm.
• Axle Material: Steel
• Bearing Material: Steel
• Bottom Bracket Cup Material: Aluminum (left), Aluminum/Steel (right)
• Crankarm fixing bolts sold separately.