see if there is an army navy surplus store near by and check there for flight boots laces . Most of them were speed lace and they are made to last. THey are not elasstic,don't stretch and are tough as nails. Make sure they are for flight crew boots not normal combat boots.I have an old pair of wading boots theat are done with speed laces and a friend got me my new laces at a surplus store their 5 yrs old,with no signs of giving out anytime soon.