I built one of these last night...$5 wheels from grizzly.com ($15 with shipping) Used a candle flame to bend the 3/4 conduit. Total time 1.5 hours...total cost ~ $25 (including foam pipe insulation for padding).

Thanx John....very simple and effective idea.

: Someone on this board was experimenting with PVC ribs for a SOF boat. That
: got me thinking about a kayak cart built of PVC tubing after attempts to
: shape aluminum tubing with a pipe bender proved less than satisfying.

: I have taken 3/4" electrical PVC conduit (it has thicker walls than PVC
: for water lines), filled it with sand to help it hold its tubular shape in
: the curves, and heated it with a heat gun until it becomes pliable (only 3
: or 4 minutes)to make the bends. The finished piece looks like an
: "M" stretched sideways. The top piece of the M (the piece on top
: of the "legs") I bent to fit the approximate shape of the bottom
: half of form 11 or 12 of my G17. Then it's a simple matter of bending the
: ends down to form the legs. The length of the legs is a matter of
: personnal preference, but if you want to store the rig in the hatch
: without removing the axle, they cannot be longer than the hatch width.

: To make the second part of the frame, make a second "M" the same
: shape as the first but sized so it fits inside the first piece (i.e. the
: top piece will be a couple of inches shorter as will the legs.) That way
: it all folds flat.

: At this point you could lay the two M's on a flat surface (one nested inside
: the other), and with a straight edge about one inch from the bottom of the
: legs mark for the axle and drill. For a light boat that might be strong
: enough, but I strengthen the axle area by gluing (PVC cement)a slip
: coupling on each leg before drilling. (A slip coupling is normally used to
: join to pieces of conduit. The coupling usually has an internal rim at the
: centre that you must remove first (about 2 minutes with a rat tail file or
: a dremel tool)so it can slip all the way on.

: I use 1/2" solid aluminum rod for an axle. The best looking wheels I
: have seen are the 8" plastic spoked wheels they put on some jogging
: baby strollers, but short of buying a stroller I haven't found a source
: and I'm making do with the large plastic-centred lawn mower replacement
: wheels most hardware stores carry.

: Fasten a strap in the valley of the top pieces to fix how "open"
: you want the cart to be for your boat. Afix straps on one shoulder of the
: M, which will pass over the hull and secure to the opposite M to secure
: the boat to the cradle.

: For protection of the hull you can add lengths of 3/4" foam pipe
: insulation, or, if you want to minimise volume, you could glue on strips
: of something like the 1/8" closed cell foam craft stores are selling
: in 1'x2' sheets for hobbyists.

: I'm amazed at how strong this rig is. A couple of final notes: remember to
: take the thickness of the foam padding and the thicknes of the slip
: fittings into account before you bend the second piece so it nests
: properly. You want the feet, with couplings on,to be touching to make
: lining up and drilling for the axle easier. The length of the legs depends
: on how much ground clearance you want, which is dictated in part by the
: size of the wheels you use and also your hatch opening.

: Finally, as you make each bend, lay it on a flat surface to make sure you are
: not adding a twist and hold the bend for a couple of minutes until it
: cools sufficiently to hold the shape. I used 45 inch piece initially for
: the outer M with the leg bend about 10 inches from either end. But that
: didn't fit through the hatch unless I removed the axle, which is simple
: enough. For the second cart I reduced the leg length to about 6 inches,
: which fits the hatch better but trades off ground clearance. Experiment.

: All the parts are available at any typicaly Home Depot style oufit.

: Cheers.