If you share your wheel tire combination with the measured true outside diameter when fully inflated I'll add them to a table and post all the results in any easy to read form. Please include make model of tire and psi range.

My reason: Bicycle tires contain carbon, for grip, but therefore leave marks; wheelchair tires are non marking but only come in the standard size (wheel diameter * 1"). I want to use the largest tire wheel combination for outside.

I currently use bicycle tires as they come in sizes I prefer, but they leave horrendous marks over time in the house. I would like to swap wheels when I come into the house, to non-marking tires without having to do any adjustments to my chair etc.

So if I can figure a wheel tire combination that are the same this maybe a possibility.

Have just done some real life measuring with what I have available:

everything is a standard wheelchair 1" wide wheel rim.

I'm currently using:
25"*1" rim with a tire - 60-559 (26*2.35) 30-55psi Big Apple Schwalbe actual outside diameter @55psi 26 7/8"

Other measurements I've gathered.

25"*1" rim with a tire - 37-559 (26*1.5) 45-85psi Non Brand cycle tire actual outside diameter @85psi 26 3/8"

26"*1" rim with a tire - 42-590 HS 349 Schwalbe actual outside diameter @maxpsi 26 1/2"

I'm thinking of running my 26" rim with the standard non-marking tires, then using the appropriate tires on the 25" rim to achieve the same true outside diameter.

I thought I had some old non marking 26" tires, but can't find them!

If anyone is running 26" rims with a non-marking tires, would you measure the actual outside diameter of the tire when inflated to MAX psi and note the make and model of the tire, and share.

even if it's only an 1/8" difference, want to find the non-marking tire that gives the largest outside diameter on a 26" rim.