Resurrecting this thread. A week ago, my seat popped out of position while riding. It had just worked loose while sitting over the winter I guess.
To this point, the seat was at a setting done by the LBS and it was good. But I didn't really keep track of where it was (I should do that now that I think about it, in case I have to do something with the seat post or who knows what else).
I put it back to where I thought it was and I started getting some crotch pain I didn't have before. Half way through a long ride this weekend, I bumped the nose down a couple of degrees and it felt WWAAAYY different. Like I was sliding off it. ia couple of degrees felt like 20 - 30 degrees. The difference was dramatic. I stopped, loosened it up and tapped it back a little. It made things much better, but hand numbness returned as well as tired arms.
I'm going to adjust it again, I think I'll get it back in place with one or two more adjustments. I'm just glad nothing else on my bike has shifted. Imagine how much screwing around I would do trying to get everything back to the way it was. [Seriously, the more I think about it now the more urgently I feel the need to go write down all of the measurements on my bike].
I guess my point is that one or two degrees on the seat as well as it sliding back or forth a centimeter can shift you from crotch pain to falling off the seat to numb hands and arms. Getting your bike properly fitted can make a major difference and is well worth the money.
Also, I'm glad that I'm getting molded into my bike well enough that I notice such things. I'm not sure I would have noticed it a month ago.