Tyre dimentions explained
 

Hi can someone please explaine to me how a '4.60 'correspods to a 120 /130 / 140 tyre?

Thanks George

130/90-17

130mm wide, 90% profile so the sidewall is about 117mm from the rim to the road, 17 Inch rim diameter.

4.60-17

4.6 inches wide, 17 inch rim (profile is typically 90% but it's not stated)

As 130mm is 5.1 inches, the metric example is wider but will fit the WHEEL. Doesn't mean the wheel will then fit the bike, the extra half inch might foul the chain or swingarm. More info here:
Continental Motorcycle TyresÂ*-Conversion chart - motorcycle tyre sizes

Andy

Thanks Andy that was just what I was looking for!

George