You have to tie them at the exact right length, otherwise they will not work well. I made a jig with a piece of wood, a nail, and a push pin. The manual gives you the distance for the nail to push pin span. Use the same material, which is like $5 for a mile of it. I've tried the others and nothing worked as well at holding the knot. If you mail a self addressed stamped envelope to WT USA they will send you free ones with their belts for life policy. Unfortunately you'll be doing this a lot if your belts break as often as mine did.