How big a tri a single crew can handle is very much a function of design, where you’re sailing, and experience of the driver. At the extreme end of things you have the singlehanded racing tri’s. These have huge rigs and are very tender. Make a mistake in 18 knots of wind while reaching and you’re going to finish the passage on a freighter (or some other good Samaritan). You can back off from there, but as you can see, there are no pat answers.

Regards–Steve Dashew