The easy way to sew a triangle crotch leggings gusset: Aila tutorial

The Aila leggings has an optional triangle crotch gusset. Now sewing gussets can feel a little bit overwhelming if you are not used to sewing these type of garments. But don’t worry, this simple 3-step method makes attaching a triangle gusset a breeze!

1. Attach one side of gusset to the crotch

Sew the gusset from the base of the triangle to the tip using a stretch stitch or a narrow zigzag stitch. Stop sewing when you hit the tip of the triangle. This will be easier if the gusset layer is on top when you are sewing.

Learn more: Best Fabric Choices for Workout Leggings: Aila Sew-Along

Tip: To prevent the edges of the gusset from slipping, use a dab of basting glue or just use a regular glue stick. You can also baste the entire side before you use the stretch stitch (image below)

2. Sew the entire back crotch seam

With this method, you’ll sew the crotch seam and the other side (leg) of the triangle gusset in one continuous seam. Place the back crotch pieces together and start from the base of the triangle and sew to the waist. Make sure the opposite seam allowance on the gusset is folded outwards.

Learn more: Video: Sew Your Best Leggings Ever

3. Topstitch the gusset

To avoid chafing seams, you can topstitch the gusset seams using some type of decorative sewing machine stitch that has a good stretch. I recommend doing a sample first to make sure the seam will both work and look good.

You can either stitch over the folded seam allowance.

Another option is to sew the crotch seams using a zigzag stitch and then press the seam allowance apart. This will make topstitching easier since the seam is much less bulky. In this example, I’m using the 3-needle coverstitch to crate a mock-flatlock effect. But you can also use a decorative sewing machine stitch.

Learn more: How to Hem Leggings: Aila Sew-Along

A third option is to just use the 2- or 3-thread flatlock serger seam and sew the entire crotch area using that stitch. A serger flatlock is however less durable than the method described above, but it can look very similar to a professional flatlock stitch and there will be no chafing seams on the inside.

Stitch together the remaining seams

Start by sewing the front crotch seam. Then sew the entire inseams. Start from the lower leg opening and sew the entire leg seam including the gusset in one continuous seam from leg opening to leg opening. Make sure the gusset’s seams are folded outwards, and that the front crotch seam aligns with the triangle midpoint

The finished gusset

That’s it! I know some other pattern companies use a more intricate notch system for their triangle gussets, and that is helpful too, but this method really simplifies the process even more and works just as well in my humble opinion.

Using a crotch gusset is an option that comes down to preference, hence why I made it optional for my Aila leggings sewing pattern. But it does help increase the lateral range of movement and can prevent chafing too, so worth giving it a try for sure!

Watch this video tutorial for even more sewing leggings tips!