Ken,
Yeah they are 26 incher's and I didn't fall, I went down into a compression ( a big dip if you will)and back up and I think I compressed my back somehow. I was standing on the pedals the whole time and used my legs and front forks to take the compression but...I don't know it was weird and still hurts a bit today.

Started out this morning (10/25) and it was 49 degrees out, 49 miles later it was 54. The last 20 something miles were into a headwind and I was looking for shortcuts to get home faster. All in all not too bad as I rode a new route, well had new sections added to a route I use a lot. It was a beautiful morning though and very colorful what with the leaves changing and all.