Please explain how you tighten or lock the the initial stitch in the city grips. It seems in the YouTube instructional video the the first stitch still has thread hanging off by the time you finished with the surgeon’s knot.
In the video, I use one needle, and one length of thread.
This requires a knot to be tied at each end, but to make sure to pull the thread down tight, first I stitch the thread all the way through, leaving one end slack. Then I go through it again, pulling tightly to cinch the leather together, before tying any knots. At this point the thread it tight and there is no knot on either side; and the thread doesn’t become loose.