Im a little confused on a couple of things. 1. Is the tires metric or standard? Im thinking standard but im not to sure. 2. Is the the tires tubless or have a tube? 3. According to the chart above my tires size would be what? Front tire: 90×54×21 Rear: 150×80×16 .....to put in the calculator? Just unsure on those things. But putting the stuff according to the video seems pretty easy!