About 2 years ago I started making plans to build a bike for the salt-flats. I knew it would be a Triumph Cub with about 20 hp and rather light, yet it had to carry my 200 lbs. of body weight. I did not consider the amount of energy or power I would need to overcome rolling resistence. Rather, I thought about selecting the lightest, roundest, narrowest, firmest, and most reliable tires and wheels available within my almost nothing budget. From a practical point of view, I know that once the wheel is put into motion, a larger diameter is easier to push or pull with my own strength, such as a wheelbarrow or wagon. Practical experience seemes to work. I can almost effortlessly push my bike across the salt with one hand and when I stop I actually have to reverse my effort on the bike if I want it to stop with me. That's my formula......Oh, BTW.....how many minutes does your wheel keep spinning when suspended after you give it a good start ?