American Skier trailers 1977-90 and again from 1996-2001 all used 5 lug 14" wheels & tires and the trailers were built "in-house" at the boat plant. During those years there were two exceptions that I know of, west coast boats seldom used A/S trailers, instead a local California trailer builder fabricated trailers for the west coast dealers, and my old shop Midwest American SKier fabricated our own A/S clone trailer. In both cases 14" wheels were used. The MWAS trailers had longer side steps, and offered optional shock absorbers on the axle and came with custom pinstripes (younger brother Dan fabricated many of these). The reason we didn't buy the A/S trailer was to maximize the number boats that could fit on an 18 wheeler to maximize shipping. However Wesmar years and Elan years (91-95, and 2002+) used a variety of parts, suppliers, and many were built entirely by outside trailer manufacturers. The 6 lug 15" hub/wheel combo has higher capacities but did not fit into the original chassis without changing all the jigs, when we needed added capacity we added another axle.