It is not easy to measure the radial clearance of the whole set of bearings. The measuring force causes the elastic deformation of the ring and the rolling body itself and its contact. The deformation is a multi-factor causing the measurement error, which is related to the measuring force, the contact state and the position of the rolling body. 

The flexibility of bearing rotation is generally checked in the horizontal position. Usually, the inner ring is fixed (or the inner ring is held in hand), and the outer ring is rotated by hand to check whether there is any abnormal sound and blocking phenomenon when the bearing is rotating.

Generally speaking, when the bearing rotation of the duration of a long, slow stop, flexibility is good.Conversely, the rotation time is short, stop suddenly, flexibility is not good.Due to the bearing structure type and size, there should be different requirements for its rotation flexibility.Such as single row centripetal ball bearings, single row angular contact ball bearing, due to small contact area between ring and roller, the bearing rotates is brisk, and double row centripetal spherical bearings, thrust roller bearings, as a result of the rolling element and raceway contact area is larger, and the weight of the outer ring is small, when check the rotation flexibility, coupled with a certain load, but its light degree is still less than single centripetal ball bearings.

For oversize bearings, when rotating it, there should be no jam, and generally do not check the rotating sound.For tapered hole bearings, the following methods can be used to supplement the inspection of the flexibility of the bearing rotation, the specific operation is as follows: the cone hole bearing is pressed into the mandrel until a certain radial preload is added, under this preload, when a ring rotates, the rolling body shall rotate.If the rolling body slides instead of rotates, it means that the ring geometry is too defective or the rolling body size is not uniform, and the rotation flexibility of the bearing is poor.