Could also be a question of fit: It's now the fourth time that my trousers happen to rip at the seat. This pair is cut rather roomy, definitely not slim. The fabric is entry-level VBC flannell (same with the other three trousers that ripped). Each time the rip has been around the same area. What could be the reason? Hip / upper leg too narrow? Insufficient flexibility of the seat's seam? Weak fabric?