Mission BMX American BB Kit

This kit is designed specifically for frames with an American bottom bracket shell. Before purchasing, ensure your frame is compatible with the American standard, as it is not interchangeable with Mid or Spanish bottom bracket shells.

The aluminum cups provide a more secure and stable housing for the bearings compared to plastic alternatives. They help maintain proper alignment under the stress of riding, which prevents premature bearing wear and ensures a smoother crank rotation.

Yes, this is a complete kit. It comes with two precision-sealed bearings, aluminum cups, a center tube spacer, high-density plastic cone spacers, and a sprocket adapter, so you have all the necessary components to get your drivetrain running.

Yes, the kit includes adjustment washers that allow you to fine-tune your chainline. This is particularly helpful if you need to align your sprocket perfectly with your rear driver to prevent chain drops or excessive wear.

While the bearings are high-quality sealed units designed for longevity, they are standard size and can be replaced if they eventually wear out. You do not need to replace the entire cup assembly if only the bearings need servicing.