Single row deep groove ball bearings are the most commonly used rolling bearings in the bicycle industry, including the bottoms brackets.
The balls run in deep grooves in both the outer and inner rings. This enables the bearing type to accommodate radial loads as well and some axial loads in either direction, but are not suitable for medium/ high axial load
Single row angular contact ball bearings support axial loads applied at a certain contact angle to their axis in one direction only. These bearing types are not separable; therefore, they are mounted in bearing pairs or a combination of bearing sets./span>
A ball lying on a flat surface makes contact at a single point. This is termed “point contact”. In practice a ball under load will have elastic deformation. The curved shape of ball bearing raceway changes this contact shape to become ellipsoidal.