Found a couple of things. The post I had seen with a ratio for the rear/front combo.
http://www.tractorbynet.com/forums/john-deere-buying-pricing/130217-front-rim-jd-4100-a.html
I couldn't come up with anything that seemed to be near the right value, using the formula in the post above, until I divided the loaded radius for the rear by the loaded radius for the front. All of those came up to be near 1.5, except for the combination I now have. It is about 1.3. I did find a Goodyear titan tire in a 22x9.5x12 which puts mine into range. That may be an option. I would like to have a little clearer understanding of the formula from the prior post, before I buy something.
http://www.tractorbynet.com/forums/john-deere-buying-pricing/130217-front-rim-jd-4100-a.html
I couldn't come up with anything that seemed to be near the right value, using the formula in the post above, until I divided the loaded radius for the rear by the loaded radius for the front. All of those came up to be near 1.5, except for the combination I now have. It is about 1.3. I did find a Goodyear titan tire in a 22x9.5x12 which puts mine into range. That may be an option. I would like to have a little clearer understanding of the formula from the prior post, before I buy something.