Unfortunately they are obscenely too small for him now, never mind when he would wear them three months for now. Into the hand-me-down box they went. Cue the tears. Huge, pathetic tears. So I promised him new ones. Lots of new Prefontaines.
Since it's a bit too cool here for shorts I lengthened the pattern in to Prefontaine Track Pants. Success! They're great comfy, wide leg pants. Or hell, even jammies. Lord knows Jimmy would wear them day and night if I let him.
Here's how you do it:
Use a clear gridded quilting ruler to mark a line 1.5" above the bottom of the front pattern piece parallel to the bottom edge. Make sure the line you makre is above the entire retro curve of the side seam, but below the crotch point. Mark a second line on your back pattern piece the exact same distance up from the bottom hem. Cut the bottoms off of both pattern pieces along those lines.
Measure your kiddo's hip to ankle length. Tape paper to your both pattern pieces. Reattach the retro curved hems of the pattern pieces so that the length of the pattern's side seam is your child's hip to ankle length plus 1.5". True the inseam pattern lines to match crotch points and bottom hems.
You will need to make a longer length of "bias" tape tshirt trim but one upcycled tshirt was still more than enough. Then just assemble your track pants as you would the Prefontaine Shorts. Easy, peasey. Now I've got one happy boy.
Don't have a copy of the Prefontaine Shorts for Kids pattern yet? It's part of the Pattern Parcel #2 sale as the Bonus Pattern. Or you can get it directly here.