Finally have the straight scoop on my accident. The problem was the rear tire which lost its air due to a bent stem. I filled it up initially and once when it was flat (should have checked it out better then). Finally, I took it apart today and found a damaged stem, I suppose damaged after the tube had lost air. The stem itself (all metal) had a place at the tip that was torn up a bit, and the stem itself was bent. I suppose I might have found this through a little care when I refilled it the first time, something must have caused it to lose air. Anyway, I will put a new tube in this afternoon, hoping that it will hold air better. So a lot of my figuring was in error - thinking I had dodged a cow, etc. when I went down with a flat tire. The tire itself is new, an Avon and the tube was new too, but maybe wasn't installed by me quite right, such that it lost its initial air, then lost it again before the accident.
After this I plan to get to work on the rickshaw, just minor things needed to complete it. The thing with it is that I don't yet know what my range is with it. It will be fine once the new bridge is finally in (lots of talk, little action). It is only a little over 2 miles into town, but each time I go without the bridge it is more like 40 both ways.