Here’s a clever cart that will fit in your hatch. You might not think you need one, but just wait until you’ve got 100 lbs of gear in the boat and you’ve got to get it up above the high tide line. There are more construction details at the West Coast Paddler website.
I’ve finally made the time to make a pair of these carts for myself. I used 1″ pipe and fittings, but used a non-neumatic tire (about $5) from an import tool store (not HF) in Vegas. I also replaced the pool noodles with 1-1/8″ pipe insulation available at the big box stores. The type I used is neoprene foam, which looks like wet suit material. After getting it home and cutting it, I realized that although it’s a better insulator, it’s very fragile. I think the stiffer (and cheaper) pipe insulation is a better choice.
Making the cart requires some attention to the axle. I was able to turn a maple plug for the cylinder in the fitting where the axle is bolted, which allowed the use of a 3/8″ lag bolt instead of a machine screw. The plug was sized to achieve a very tight fit. In addition, it the plug is secured in the fitting with a #8 1/2″ sheet metal screw. This prevents the plug from turning or pulling out. You can see on the partially completed plug there is a change in diameter along its length. This is required in order to get a tight fit in the part of the fitting where a 1″ pvc pipe would have been glued. The smaller diameter of the plug protudes into the body of the fitting and over to the other side.
Once the plug is turned, the small end needs to be rounded to fit the contour of the far wall of the fitting. The image shows the plug inserted 90% into the fitting. Once it is fully inserted, the protruding length of the plug is cut off with a bandsaw and then sanded flat to match the end of the fitting.
If you don’t have access to a lathe, you can make this cart shorter by replacing the cross pipe with a solid axle straight across and a 1″ glued between the axle fittings. The advantages are (1) the solid axle resists the bending moment from the wheels and (2) the overall cart height is less. You have to be careful that your tire diameter allows this. The disadvantage is that the wheel nuts have to be undone and the wheels removed individually to pack the cart in the kayak hatch.
The finished cart seems very stable. The wheels are retained in their parallel orientation by 1/4″ X 2″ ”D” pins. The carts are slightly different in width–the wider cart is designed to fit the second panel from the keel of the Coho. The narrower cart puts its support arms about 2/3 span of the bottom panels of the Tern. The sticky edges of the insulation seemed adequate to close the tubes around the PVC, but I added electrical tape, for good measure, where the fittings were larger diameter than the pipe.
An initial test will be to fabricate some circumferential straps, load up a kayak to about 130 lbs, and tow it around… which is now done, but with only 70 or so pounds of water. This is more representative of the actual load, I believe. The two 5-gallon water tanks are not quite full.
It turns out the center of gravity with the water is somewhat further forward than I expected. You can see where the cart is located and the kayak is nose down, although it is very nearly balanced.
The real test, however, is how the axles work under load. This last photo shows a noticeable kant in the wheels. The wooden plug in the bottom PVC fittings is evidently moving a bit. Despite this, the cart tows easily and there is no wobble, despite the wheel angle. The true test will be on the portage trails at Bowron in August. More on that later, and a separate page on Bowron itself.