Using the Moment-Balance formula:

C = (P . L) / (2 . I)

where:

P = Weight of the load being moved (N)

L = Distance between the load and P, the suspension point (mm)

I = Distance of bearings from the suspension point (mm)

C = Maximum allowable static force per bearing

Assuming the bottom pair of bearings are level with the point of suspension then I = 500mm. The load is cantilevered out at 600mm and hence this is the value of L. Here P is 20000N.

Substituting these numbers into the equation gives C = 12000 N

Looking up this value of C on the Hertzian Pressure table shows that 4.058 is the required bearing size.