looking to replace the rear tire on my 1975 xs500. right now it has a goodyear eagle hst mv85v18 on it that is weather checked. this tire looks as if it had been rubbering as well with the previous owner. wondering what range of tire sizes i can go with and also what type of tire. the one thats on there now looks like a dirt bike-ish tire. can i go with a more street bike style tire? the bike will be mostly street / hwy driven. thanks for any input.

The original size should have been a 4.00x18. My opinion is to stay with that size. Don't go with a newer size designation even if there's a cross reference saying they're the same. Seems to me that even with the same size designation , tires can vary in actual size between brands. IRC, among others I suppose, makes a "street" 4.00x18.

The front tire should be a 3.25x19. I put a new IRC tire of that size on my 74 TX500 and there's only about an 1/8" clearance between side of tire and the main center fender support!