My Sporty will need a new front tire shortly after 7000+miles. It's the original tire, HD branded (who manufacture these?). More to the point, I have noticed a slight discrepancy in the thread wear. There is very marginally more wear on the right of the tire. Is it because: 1 Riding on the left the right hand corners are longer 2 When I ride somehow I don't sit exactly on the centerline of the bike. 3 The geometry of the bike is not truly square. 4 Something I haven't thought about.