Shimano BB-UN300 Square Type Bottom Bracket

The Shimano BB-UN300 is a square taper bottom bracket built to deliver long-lasting performance and dependable support for your drivetrain. Designed with Shimano’s renowned durability, it’s ideal for recreational and everyday riding.

Smooth, Stable Operation: Featuring cartridge bearings, the BB-UN300 offers smoother rotation and reduced friction over extended use. Its internal construction ensures a sealed, maintenance-free experience that stands up to weather and debris.

Improved Chainline Stability: The integrated chain line stabilizer helps maintain precise alignment, contributing to better drivetrain performance and gear shifting. This feature is especially valuable in keeping your ride efficient and responsive.

Multiple Structure Options: Whether you ride with a standard setup, E-type front derailleur, or chain case, the BB-UN300 supports all three configurations. This makes it a flexible upgrade or replacement for a wide range of bicycles.

With an aluminum adapter and steel axle, the Shimano BB-UN300 balances strength and weight. It’s a cost-effective solution for riders seeking Shimano reliability without compromising on quality.

We ship across India. Shipping is free on orders above ₹2,000, and ₹99 is charged on orders below ₹2,000. Cash on Delivery is available for orders up to ₹20,000, with additional COD charges based on order value. Most orders are delivered within 3–6 working days, though delays may occasionally occur. Please note that most Shimano products may take longer to ship. View full shipping policy.

Returns can be initiated within 7 days of delivery. Items must be unused, in original condition, and returned with all tags and packaging intact. Returns are available only on select categories such as apparel, helmets, jerseys, gloves, and similar items. Wetsuits and products discounted above 5% are not eligible for return.

Returns are not accepted for compatibility-related issues unless the product description on our website was incorrect. Return shipping must be arranged by the customer, as pickup is not available.

For eligible returns, you can choose an exchange, store credit, or a monetary refund. Refunds are processed after deduction of applicable shipping and transaction charges. Order cancellations are only possible before the order is processed. View full Return & Refund Policy.