Bought 8N a few years back & it has motorcycle tires on it & has functioned fine until weather cracks resulted in failure on one. So, hey, it worked a long time & used MC tires are free, so I got more. Problem. Got on rim but when pressurized it won't fully seat at bead. It is as though the tire is some fraction of an inch too small than the 19 inch rim. Proper Ford N tire was 4 X 19 as was the removed MC tire and the "new" MC tire is 90/110 X 19. 90mm=3.54 inch and 110mm=4.33 inch. It seems that 19 inch isn't 19 inch? Experiences or ideas?