I have a 8 yr SD with suspension forks, tires are 13 X 5. - 6. Really tired of airing up the tires every time I mow. Looking into replacing these with flat free tires. My question is to the sizing of the tires. Presuming the 5.00 is the width of the tire. So far all I've found is 13 X 6.5 - 6 with the corresponding arbor of .75. If I'm right, and hoping someone with any knowledge of this will chime in, the 6.5 will not fit the fork. Thanks