On Jun 1, 12:37 pm, "Leo Lichtman"
wrote:
I won't bore you with the details of how I built my trailer, but I do think
you may be interested in my hitch. I clamped a short piece of conduit
pointing rearward, onto my seat post. The trailer tongue was a matching
length of conduit--I joined the two with a short length of Tygon tubing,
which gave me the needed universal alignment action, and could be
connected/disconnected by a hose clamp.

Bike Friday uses something vaguely similar: a short length of rubber
hose with a quick release hose fitting, the kind of thing available at
many hardware stores.

The bike frame has a threaded boss into which the male portion of the
air QR threads. The female part of the QR is mounted in the normal
way on the end of the 6" hose.

The QR allows rotation and the hose gives flex for turns. Releasing
is a no-tools operation that takes about two seconds.

But I've heard at least one account of the hose failing on a long
tour.

- Frank Krygowski