Today we're going to be taking a look at the Harley-Davidson spare tire cover. This spare tire cover is going to fit most tires with a diameter between 27 inches and 31 inches. The tire that I have it on today is a 29 inch diameter tire. You can measure your diameter by measuring from the top to bottom of your tire and you want to do that when it's properly inflated. If it lands between 27 and 31… see more >