A rolling element having comprises an inner ring, an outer ring and a
series of rolling elements which are in contact with the raceways of the
rings, an ultra-low viscosity fluid being present in the contacts having
a kinematic viscosity .nu.=(.eta..sub.o/.rho.) of less than 2 mm.sup.2/s,
wherein the surfaces of the rings and the rolling elements have
asperities which can have solid-to-solid contact during operation of the
bearing. A factor D.sub.q is defined which is equal to
(I) whereby the solid-to-solid contact of the asperities is reduced by
selecting such design parameters and operating conditions of the bearing
that D.sub.q is in the range from 8.0.times.10.sup.-6
mrad s.sup.1/2 to 1.36.times.10.sup.-4 mrad s.sup.1/2.