At the bend of the rail and edge of the clamp if you use have the clamp set so the corner is into the bend, esp if the corner is a hard angle. Ti is more sensitive than steel in those conditions. You can improve the seat clamp by filing a nice radius into that corner. But it took killing the most expensive seat I had ever owned to learn that. (I'd been slamming steel railed seats for decades.) Bike fit for me was dependent in part on how well that slammed seat worked in the big picture. Another factor that was always at odds with that was the fact that I do best with my rear wheel as far forward as possible to best distribute my weight between the wheels; hence steep seat angles were good. The discovery of large setback posts - a revelation.)

Ben