1.Rims with tires, which is the overall taller wheel. The 30 inch or the 21 inch?
2.The 21 inch wheel uses a wider tire then the 30 inch?
3.Because the 21 inch wheel spokes are shorter in lenght then the 30 inch, are the 21 inch wheels stronger?
1. Probably depends on the manufacturer of the tire. It's six of one or a half dozen of the other.
2. Yes, the 21" uses a 4.40" wide tire and the 30" uses either a 3" or 3.5" - all of these tires are 100% aspect ratio, I believe.
3. Probably. Also remember that the 21" uses lower pressure balloon tires so shock loads are less for the spokes. Ride has to be better, as well.
21 + 4.5x2 = 30
23 + 3.5x2 = 30
24 + 3.0x2 = 30
Balloon tires appear lower because they're fatter. There's a differenc of maybe an inch, depending on tire mfg.
It's the leverage at the hub that counts, and it's the same on all three sizes.
Unless you're willing to do a test like this on your wheels, it would be a good idea to just leave your T in the garage.
Good point about the shock, Seth. That's doubly important if the spokes are brittle, like oak or maybe aged hickory.