Originally Posted by crying_koneko
Also try a ballpointed sewing needle for your machine they're duller and will move the fibers aside, not rip through them.
No, you actually don't
want to use a ballpoint needle on lycra. Ballpoint needles are meant for knits that don't contain high amounts of elastic.
To sew with lycra properly, you must use a special kind of needle called a stretch needle. A stretch needle is meant for high-resistance/high-elastic knits. It has a deeper gouge in the back so that the machine hook can properly lock your top and bobbin threads together. If you use any other kind of needle, you will get tons of skipped stitches and you may also end up with thread knots in the feed dogs or bobbin area.
You also need a machine with a zigzag stitch or a mock-serge stitch. The width of your stitch is proportional to how much stretch you need, because as you stretch the fabric the stitch will become straight. So, a width setting of 1mm will have very little stretch, and in a high-tension area your thread will break.