Too bad, because all bearings are standardized throughout the world. Nothing special about OEM. Gordon Jennings (RIP) had a good article about bearings years go in Cycle World magazine and made this point.
Go to the VXB website and look at the specs for 6204 & 5204 bearing that fit the ST1100 front & rear wheels. Specs are way above what is required.
Example: 6204 spec are static load 6.55KN ( 1,472 Lbs ) , dynamic load 13.5KN ( 3,035 Lbs ), max speed and still maintain lubrication of 10,000 RPM.
5204 : spec are static load 12 KN ( 2,698 Lbs ) , dynamic load 20 KN ( 4,496 Lbs ), max speed and still maintain lubrication of 10,000 RPM.
A rear wheel speed of 10,000 RPM would be about 775 mph.
Three 6204's and one 5204 equals a max allowable static load of 7,114 Lbs and a max allowable dynamic load of 13,601 Lbs. Plenty good.
And I have been using these VXB bearings for about 45K miles without a problem - still rotating nice & smooth.