Keep rollin' to make it easier to take your canoe or kayak across land. 

Printing: bracket and hub out of your favorite plastic, I used PCTG. Tire should be soft, I did TPU with 2 perimeters, 3 top/bottom (0.2mm) layers, 10% infill. V with TPU a bit stiffer, 3 perimeters, 20% infill.

What else you need: M6x50 flat-head bolt is barely enough, 60mm works fine as well. One M6 nyloc nut, some washers. Two 16x6x5mm ball bearings. If you have different bearings, adjust the b123d code. Some bungee cord, mine (and the holes) are for <8mm cord.