Originally Posted by Trakhak

Wool tights? They were notorious for sagging when that was all we had available for winter riding in the '60's and '70's and might well have been one of the reasons Assos came up with the idea of Lycra tights and shorts.

If they're not wool, if you've never worn tights made with heavyweight Lycra, maybe think about getting a pair. Expensive (usually), but no sagging.