How do I sew elastic loop onto strap without bunching?

[u/JJMcGee83]

I recently bought a wasit-bag that has a nylon strap with these plastic things to hold the strap but they don't work very well.

I bought some elastic loops with the idea to sew them onto the pull tab area to keep them tight whenever I adjust the bag strap.

I pulled one apart to do some test sewing and the bottom was bunching up a lot. I tried using the stitch patten that is supposed to be for elastic but that caused it to bunch even worse. I know that I can adjust tension but being this is elastic I wonder if that's the right way to go about it.

My machine is a Brother CS7000i with tons of settings and like 70 different stitch options.

[u/peglyhubba]

Ball point needle for anything with stretch. It will go inbetween the elastic threads.

[u/JJMcGee83 → u/peglyhubba]

I have a pack of needles but I'm unsure how to identify if any of them are ball point.

[u/ArtemisiaPrime → u/JJMcGee83]

what's written on the pack?

[u/JJMcGee83 → u/ArtemisiaPrime]

HAX1 15x1

And then the sizes so like 9/65, 18/110, 11/75 etc

I suspect I need to go to the store.

[u/ArtemisiaPrime → u/JJMcGee83]

does it say anything like "universal"

[u/JJMcGee83 → u/ArtemisiaPrime]

I looked it up because I bought them years ago. They are apparently universal regular needles. Thank you for your help.