Originally Posted by crankshaft
R U sure? I have a 100/100 rear and the sidewall is really short. The 100/80 has a taller sidewall.
100/80 means 100 mm wide x 100*80/100 = 80 mm heigth As you can read in the link, it's the aspect ration, and it is exactly the same principle with car and truck tyres.
The lower the aspect ratio, the sportier it is. Typicaly, sport car tyres have aspect ratio in the area of 30 to 40.
That said, the end result is not always in sync with the reality. Dunlop D606 130/90-18 are as wide as Pirelli MT21 140/80-18, and as tall as well ... It's not an accurate science ...
Paul Jr 8