Thank you very much. I figured out how to do the custom setting. The tires are marked to be inflated from 40-60 psi, so I inflated them to 50. I then sat on it as best I could here in the living room without risking major injury while marking out one revolution of the front tire starting with the valve stem down. That came to 78.5". I multiplied that by 25.4 and that came out to 1994 and that's what I set it at.