have rollers that are thicker in the middle and thinner
at the ends; the race is shaped to match. Spherical roller bearings can thus
adjust to support misaligned loads. However, spherical rollers are difficult
to produce and thus expensive. Spherical Roller bearings have higher
friction than a comparable ball bearing since different parts of the
spherical rollers run at different speeds on the rounded race and thus there
are opposing forces along the bearing/race contact.