I needed a simple cheap dolly to move my SUP from my boat house to the water.  Using leftover 3/4 inch PVC pipe, elbows and Tees, two lawnmower wheels, 1/2 inch copper pipe, a 1/2 inch threaded rod with washers and nuts, and 3/4 inch oak dowels, I made this self locking dolly that securely holds the SUP without tie downs.  Total cost $34 for the wheels and $4 for the threaded rod. You just slip the dolly over the stern up to the fins, lower the stern to the ground, pick up the carry handle on the bow and away you go.

Three quarter inch PVC pipe has very little resistance to bending (if someone on the beach steps on it, it will break), so I inserted a 3/4 inch oak dowel inside each PVC piece except the one on the bottom (the axle).  Inside the PVC axle is a 1/2 inch threaded rod which just fits the bushings on the lawn mover wheels.  To protect the PVC pipe from being crushed by tightening the nuts holding the wheels on, I cut a piece of 1/2  copper pipe 1/4 inch longer than the PVC on the bottom.  The washers and nuts abut the copper pipe and exert no pressure on the PVC.  The plastic foam is 3/4 inch pipe insulation which grips the boat without scratching it.

I am so glad you posted this..the method of use is so simple.  Do you use any bungies to tie it on, or does just the leverage of the two pipes hold it on by itself?.

I was thinking about making one for my dory out of wood after the model shown below, but I like your PVC pipe with inner support method better.   I am hoping I can scale it up to work on my CLC Dory.   For tires I was planning on using those little inflatable tires that come with the kayak dollies.  The dolly is worthless otherwise because you have to use straps and a kayak always comes off

The dory is about 48" wide just aft of the widest part.   I was also cogetating if it could be made collaspable but that's for version 2 I guess

Do you think this idea would scale up to the dory OK?

Thanks

Curt

   Hi Moonchaser,  As I mentioned above, the dolly is self locking, requiring no bungies or other tie downs. You just lift the stern, slide the dolly on and go.  At the water, you lift the stern and the dolly slides off.  The secret is the middle bar which carries the weight of the boat.  That weight rotates the dolly on the axle, pressing the top bar down on the boat deck. If the boat sits directly on the axle and not on a middle bar, the padded bars do not clamp down on the boat.  This design should be scalable to a larger boat, but I would consider using 1 inch PVC with 1 inch oak dowels inside the PVC for strength.  The threaded bar diameter depends on the size of the holes in the wheels. On your existing dolly you could add a middle bar 6 to 8 inches above the axle, add foam padding on the middle and top bars and it would hold the boat without bungies.

I use a similar design for my ocean (sit on top) kayaks.  I leave the top bar off and stick the two upright bars through the drain holes in the kayak.  A drop or two of wood glue holds the oak dowels in place since there is no PVC fitting at the top.

 I am an old Grandpa. To go paddling I put the dolly on the boat, grab the bow carry handle, step on my Segway and head to the water.  Enjoy.