I built a Coho, not a Tern, but I think the recommendations were about the same. At 6' 6", I knew I probably wouldn't want the peg rails where they said. Here's what I did. I taped a Sharpie marker to the bottom of my bare foot, at the ball of the foot, perpendicular to my foot, with the point of the marker to the outside. Then I sat in the boat with my legs in the position they would be in for comfortable paddling, as if the pegs were there. Not the position my foot would be in during a knee lift for leaning/edging. Then, I jiggled my foot around to mark this approximate position. This is the distance from the back band that I put the middle of the peg rail. Having this distance, I measured the distance on the other side so they would be the same. This gives me opportunity to move the pegs forward or back to suit my preferences for what I'm doing. Had I mounted them per Pygmy's generic measurement, I would have probably had to have the peg in its furthest position all the time. The drawback now is that people of normal size may not be able to reach my pegs in their nearest position. Oh well, as Derek Hutchinson says, you don't sit in a kayak, you wear it. I don't expect anybody I know to be able to wear my pants, so I don't expect them to be able to wear my kayak either.

: I'm getting ready to mount the foot pegs in my Arctic Tern but am having
: second thoughts about the mearsurements in the instruction book. Pygmy
: calls for the rear most mounting screw to be 39 inches in front of the
: back band. I tried sitting fall on the floor with my back against a wall.
: My heel was just about exactly 39 inches from the wall (I'm 5'11").
: I'm thinking that my heel should be about in the middle of the bar that
: the peg slides on, not at the near end. Have any of you other Tern
: builders bumped up against this?