Originally Posted by well biked
For the bike like the blue one in the photo, I don't see much advantage when everything is considered. Maybe someone else will have some thoughts on that. Small wheels are used for folding bikes a lot of course, which need easy portability, so there's an exception. As for the bike peripatetic's interested in, since it appears to be a sort of touring bike, and since smaller wheels are inherently stronger, the smaller wheels would be an advantage in that regard. Another advantage would be a very low center of gravity. I've seen a 20" wheeled backcountry tourer fully outfitted with racks (I mentioned it earlier in the thread), and it's obvious the bike would be extremely stable fully loaded-
Good points about stronger wheels and lower center of gravity, I didn't think about it. I was thinking about the geometry as it pertains to the rider, but yours are more important.
By the way, I wonder why is it I feel so much more stable on 700C (be it road or MTB) wheels than 26". I heard some people mention the bigger moment of inertia, but that can be achieved with heavier wheels on the 26", too, so, the physics of this don't seem obvious to me. Maybe it's a psychological thing.