I dropped my rear wheel and measured width between the chainstays where it line up with the tire and got 34mm, so around 3mm clearance between tire a chainstay. Regardless of my measurements my current tire has to be shoehorned in and it sounds like it would only get worse with a wider wheel. It’s looking like if I want new wheels I’ll have to also get new tires, and it looks like 700x25’s are going to be as wide as I should go.