What does the ply mean?>

[86250RZ]

Howdy is correct, the formula that hondaatcvabeach used only works with metric size tires i.e. 255/70/16 to get the total height you divide the aspec ratio (255) by 25.4 which will be 10.04" then you times that by the cross section width (70) .70 and you get 7.03 which is the sidwall height and since you have 2 sidewalls you times that by 2 = 14.06 then you add the rim size which in this case is 16, so 14.06 + 16= 30.06" is the total height of a 255/70/16 We use this formula for + sizing. Let say you come in with a 2000 model Ford with tire size described above and want to replace your 16" wheels with 20" wheels, you would want a 285/45/20 its 30.10" tall about as close as you will get to a 255/70/16 and you odometer and MPH will still read correctly and if you have ABS brakes they are also calibrated to the factory tire size which is very important. (there are small variances brand to brand but this will get you in the ballpark)

[plkmonster2]

The weight that each tire will hold is bull, IMHO, also. One tire will hold 330 lbs, as you say. This is one tire. You have 3 on the trike, so you can load the total weight to 3x330, or 990 lbs. Also, like all the others said :-D ply rating is different also. I've seen some 2 ply's that are more thorn resistant than 4 plys. No probs with my 2 plys, but tons witht he 4. The 2's are are hard azz rubber, almost plastic, but the 4's are soft, and thus grip much better.