Click here to view our general tutorial on adjusting the length of a pattern.
This tutorial is specific to the Sidewinder pants, with particular attention to re-aligning the "side winding" seam.
(i) Your pattern may not have the shorten/lengthen line present - but it's easy to add. Simply rule a straight line about 5cm (2") below the notch on the inside leg of both the front and back pattern pieces as shown. Make sure your line is in the same position on the front and back leg pieces (overlay the pattern pieces on top of each other to check this).
(ii) Cut a straight line with scissors all the way across the front and back leg pattern pieces along the adjustment line marked you marked on the pattern.
Measure the additional length you need to add:
> refer the pattern finished measurement chart - page 2 of the Instructions and compare this with your desired length. Calculate the difference you need to add (referred to as distance "A" on the diagram above).
> Spread your pattern pieces at the cut line so the gap between the upper and lower leg pieces equals the amount you have to add (measurement A).
> Tape an extra piece of paper in this gap to secure the additional length leaving a bit of extra paper extending either side for now.
(iii) Realign the inner and outer leg seams as shown in the diagram below:
Note you may end trimming a little off the front outside leg "sidewinder" seam but you will be adding the same amount to the corresponding piece on the back leg so the original width of the trouser leg at this point will remain unchanged.
Trim the paper insert along the adjusted seam lines and you are ready to cut out your fabric and sew.