Hy tracern1, people look at threads to see if they can answer a question, or to try and learn something, in either case expecting an answer in less than a half an hour is unrealistic at best. Using standard size bearings on a crank ground .001" undersize will give you at least .001" more clearance than the specifications call for, in effect you'd be starting from a worn position. Undersize bearings are actually thicker than standard bearings, it is the crank that has been ground "under" the factory standard size, therefore the undersize bearings must provide a hole smaller in diameter than the factory standard bearing to take up for the fact that metal has been removed from the shaft, hope that helps.
