Yea those tires were on it when I got it. I'm thinking about taking the rear tires off the 7100 and putting on the 5100. Then getting ags for the front and rear on the 7100.
I agree on the "oldies but goodies". The 7100 is a much nicer tractor, with the 4x4, hydrostat and all, but I have to say that the 5100 is just plain fun. I also love to hear that 2 cylinder diesel when you give it a quick shot of throttle.
I was really fortunate in that both of these tractors have spent the majority of their lives cutting grass, so neither have been worked hard at all. The 7100is basically like new, and with a few touches here and there the 5100 could be as well. I'm relatively new to the small Kubotas, but I have already grown to love these tractors and I'm amazed at the quality that is built into them.