Originally Posted by
3alarmer
...if you do this again,, buy a surplus wheelchair at goodwill or the salvation army. A significant number of homeless guys here use wheelchairs as gear transportation vehicles. It's not difficult to pull the wheels, hubs, and axles from a wheelchair, and they're designed to bear a heavy load. Please do not take one from someone who needs it.
Look for one not with solid tyres, but inflatable tyres to save on weight.
The problem with attaching your trailer hitch to your seat post is that all the forces from the trailer are directed pretty high up, relative to COG. So most serious trailers are designed to attach at the rear hub/dropout/axle area.
I looked all over for something reasonably priced, including wheelchairs on CL and online but they all seem to be plastic wheels these days. The older (old seems to always be better) wheelchairs with pneumatic tires are pretty expensive. Looks like $85 or so seems to be what either a cheap set of used front wheels + tubes + tires or a new utility wheelset set-up that costs about the same including shipping. My only hesitations are that the utility wheels are steel and the used aluminum will be of two different makes.
@
dedhed cycling without age was actually my inspiration when I saw it on TED talks so many years back. Finally got off my butt and this is the result. No inheritance in sight 
On the on the initial test drive it turned and stopped fine. The only issue was when I applied the brakes during a turn, the hitch spun around the seat post and it was beside the seat post rather than behind it.