Hi, I bought a Yamaha TDR 125 about 4 months ago, a friend (who knows a fair bit about bikes) said the tyres on the bike are the wrong size, the seller said they are more road rientated tyres. The tyres on the bike are front - 110/90/18 and back are 140/70/17 and the specs (found on the internet) for the bike say they shoud be front 100/90/18 and back 130/80/17 - so whos right? And does it make much difference?