Hi All The tires on my retract were replaced with radials. They measure 215-70-14.The originals were 800-14 if I recall. The speedometer is now (I think ) about 8 mph off. I guess I could get somebody to follow at a certain speed to get an accurate measure. The best thing would be to replace the trans gear. The one there now says #19. My question-- higher or lower teeth number ? Thanks Mr. Bill