The Shimano BB-UN300 is a high-quality bottom bracket designed to deliver improved performance and stability whilst cycling. It features a robust square-tapered axle and is fitted with high-quality cartridge bearings, ensuring smooth function and durability. This bottom bracket is available in various mounting styles, including standard, E-Type and chain guard options, to meet the diverse needs of cyclists. The use of aluminium for the adapter materials helps to reduce weight and contributes to the bottom bracket’s overall performance. With a shell width of 73 mm and an axle length of 123 mm, the BB-UN300 is highly versatile and offers excellent frame compatibility. The threaded cup design ensures easy installation and maintenance, making it a practical choice for all cyclists.

• High-quality cartridge bearings for improved performance
• Available in standard, E-Type and chain guard variants
• Robust square axle for increased stability
• Aluminium adapter material for low weight
• Easy installation thanks to bolted bearing cups.