Has any one tried to use 235/85-16 tires on lock ring split rims using inner tubes instead of 7.50-16? I didn't know if the bead would seat properly?

 

The bead profile on a modern 235/85R16 radial is the same as on the old bias ply 7.50x16. Both have what's called a 5° bead as opposed to the half size tires (16.5, 17.5, 19.5, 22.5) that have what's called a 15° bead profile. The only thing that I see as a possible issue is rim width. But even then that's not too much of an issue. The National Tire and Rim Association says that a 235/85R16 is spec'd for a 6.5" wide rim while the 7.50x16 is spec'd for a 6.00. They say a 215/85R16 is the correct tire for a 6" rim. The fact of your rims being lock rings won't matter one way or the other. Using radial tubes would be smart. Stu

 

so what tires would work on the 6.50 16s that were put on the f1s?

 

I have no charts that give a modern metric equivalent for a 6.50 x 16. Nobody that I'm aware of spec's a modern 16" tire for the narrow 4.5" rims used back then. To me the correct thng is to go to Coker, Universal, or one of the other specialty providers and get their modern repops in your correct 6.50 x 16 size. If somebody knows of a chart that gives a metric conversion for that size I'd like to save it for future reference. I'd venture a guess that the metric tire spec for a 4.5" rim would be a 165 or 175 width. I'm sure guys have done wider, but I try to stick with what the manufacturers specified. Stu