Stitching is coming off rear saddle bag. This part clips under the seat rails making it very crucial. Any advice is appreciated
Help! How to repair this by hand without a sewing machine?
Bike Tech and KitYes. This is the way. I have fixed similar things using a pre-waxed heavy thread for leather with a leather needle and plyers. A saddle stitch works well, since it doubles back on itself. You can Google the exact technique.
I use a sail repair kit - waxed thread, sail needle and a sailor's "palm".
In a pinch, dental floss. - old punk guy
Needle and thread. Maybe use pliers. Maybe use a thin fishing line instead of a thread (if no good thread is available). Can put a patch/sticker inside to keep the bag more or less water-resistant (but since this is Topeak, there is an external drybag anyways).
Speedy Stitcher.
I'd thermally weld it or use an adhesive like super glue to join the two pieces and assess whether you need to add some more stitching or if it would be able to be used as is.
Are you able to turn it inside out and sew it with a needle and thread? I would probably just try and return it to the vendor. Ideally this would be bartacked in place, which you obviously won't be able to do by hand.
If you area at home you can use pliers to thread (pull) the needle through some stubborn materials.
Awl or a rivet. Seamstress and gear maker here.
Dental floss (waxed) is the best for repairs like this. Give yourself plenty to use, double it over and tie one end in a knot. Stick your needle through and pull most of the floss leaving your knot and a little Loop hanging out, run it back through the material towards you and thread your needle through the loop and pull tight. Now start stitching however you feel is best to get it sewn on there. When you get to the end cut the doubled over floss. So you'll have one thread of floss with your needle still in it, and one thread just sticking up in the air. Run your needle and floss through the material and back up towards you and then pull the needle off and tie your two pieces of threads together in a few tight knots. Trim excess, and singe ends with a lighter.
Ex-seamstress here- use buttonhole or upholstery thread and a strong needle (a leather needle might be good) and, like someone else said, use pliers if it gets stuck. Try to use the holes that already exist if they haven't ripped through.
Sew at least five stitches either end that haven't come undone.
If you know how to saddle stitch, use that. If not, sew a running stitch all the way one end to the other, and then back again.
It's all black, so sewing in daylight is best, but a bright lamp will do.
(You can message if this doesn't make sense, sorry, not used to describing it written down!)
Good luck!