What Metric Trailer Tire Size is Needed For a Boat Trailer With a C78-14 Tire Size

Question:

conversion from a C78-14 boat trailer tire to metric size

asked by: Gene S

Expert Reply:

The C78-14 tire size will convert to a 6.95-14 tire size or about a 175/80-14 metric size. I do not have a trailer tire in that size. That sounds like a very old size that you are looking for.

The width on a C78-14 tire would be 7 inches and the overall diameter is around 25 inches.

The smallest 14 inch trailer tire I have available is the ST205/75-14. It has a width of 7.8 inches and an overall diameter of 26.3 inches. I am including a link to a list of the tires I have available in the ST205/75-14 size.

To find out if the ST205/75-14 tire will work on your trailer you will need to measure to make sure the 3/4 inch wider tire and 1-1/4 inch taller tire will fit on your boat trailer without rubbing anywhere.

You will also need to check the width of the wheels you have now. The smallest width rim that the ST205/75-14 tire will fit on is 5 inches. If the rim width you have is less than 5 inches then you will need to get a tire and wheel together.

The bolt pattern that is available for wheels with a ST205/75-14 tire size is 5 on 4-1/2 inches. You will want to measure the bolt pattern on your wheel or trailer to make sure you have a 5 on 4-1/2 inch bolt pattern. I am including a link that will show you how to measure your bolt pattern.

I am including a link to a list of the tire and wheel packages I have in the ST205/75-14 size.

expert reply by: Jeff D