I occasionally have pressure on my tailbone and I can't quite identify the cause of it. I can ride for days or even weeks without this, and then when conditions are just right it can occur almost daily. I'm starting to guess that perhaps it is more likely to occur when there is some climbing involved but please take that with a grain of salt.

The issue is that I may ride and feel fairly comfortable on the saddle, but if I stand up briefly to have a butt break or get off the saddle at a traffic light I feel this "sinking" feeling on my tailbone. It's almost as if riding pushed my tailbone up (towards my head) and when I relieve the saddle pressure I feel the tailbone area going "back down" towards my bottom end. As I said, I can ride 50 miles on many occasions where this particular thing doesn't happen at all. I suppose I have a bit of upright riding position, but when I am too forward I get hand pressure and numbness in the hoo ha. When I am a bit more upright I avoid that other pressure and seems to do okay on most days.

I have a Selle Italia Ldy Gel Flow with cut out and I've been hesitant to try a new saddle since I have 1500 miles on this one and no saddle sores of obvious pain. Would climbing affect your pressure points on the saddle and cause you to feel different than mostly flat roads? Would saddle pressure possible increase with tension (working hard and climbing seems to make me more tense) ?

Even if I changed saddles it could take several weeks to determine if this tailbone thing would happen again since it doesn't happen all of the time now.