BB-UN300 Bottom Bracket - English 73 x 113mm Spindle Square Taper JIS

The Shimano BB-UN300 English bottom bracket features a 73mm BB shell width and a 113mm square taper JIS spindle. It's designed to fit JIS square-taper cranksets. The crankarm fixing bolts are sold separately. With a hollow spindle, it offers a lightweight and durable solution. It comes in a sleek black color. Technical specs include a 1.37-inch bottom bracket shell inner diameter and an English BB/frame interface.

Using your Shimano BB-UN300 bottom bracket is easy. First, make sure your bike has a JIS square-taper crankset that matches this bottom bracket. Install the bottom bracket into the frame according to the English BB/frame interface. Remember that the crankarm fixing bolts are sold separately, so you'll need to attach them on your own. When using your bike, try to avoid riding through deep water or muddy areas as much as possible to prevent damage to the bottom bracket. For maintenance, regularly clean the bottom bracket with a mild cleaner and a soft cloth. Check for any signs of wear or looseness, and if you notice any issues, it's best to have it checked by a professional bike mechanic. This will help keep your bottom bracket in good condition and ensure a smooth and safe ride.