QuestionQUESTION: I am trying to find new tires for my older trailer. I understand that the new model is ST201/75 - so my questions:
D or R?
Does it make a difference since the new tires will be shorter?
What is B vs. C rated in a tire?
ANSWER: Leslie,
An F78-14ST has a diameter of 26.5", a width of 7.9" on a 5.50" rim and a load carrying capacity of 1390# at 35 psi for a Load Range B, and 1710# at 50 psi for a Load Range C.
An ST205/75R14 has a diameter of 26.1", a width of 8.0" on a 5.50" rim and a load carrying capacity of 1430# at 35 psi for a Load Range B, 1760# at 50 psi for a Load Range C, and 2040# at 65 psi for a Load Range D.
Looks like this is almost a even swap, so pick the same load range (if that worked for you.)
Some folks think that radial tires have too much sway, but I think it has more to do with the individual tire and not whether it is a radial or a bias (diagonal) tire.
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QUESTION: So how will I know if I need B or C Load Range?
Will I need to get new rims? Or will the inside portion be the same as my old?
Was the original (F78-14ST) a radial or a bias?
AnswerLeslie,
The current F78-14ST was either a Load Range B (4 Ply Rating) or a Load Range C (6 Ply Rating). It will say on the tire. Use the same.
An F78-14ST was a bias tire (the "-" indicates that.)
I'm not sure what you mean by "will the inside portion be the same as my old?" If you meant clearance, yes.
No you do not need to get new rims.
