I just posted this on another board...but some may hang here and not there. so, here goes..
I have a sargent seat on my bike. It didn't seem so loose when I first got the bike, but it may have and just never noticed. It seems excessively loose. I took it off and lowered the setting (I had it set at med) but still moves quite a bit.
I haven't noticed mine ever being loose. Is it loose side to side or is it up and down? When you say loose, are you talking about a 1/4" play or 1/2"? I've never really shook mine around to see if there is play in it.
It could be almost 1/2" rocking upwards from the back (where the seats meet).
I've disconnected it 2x and moved it to the lowest setting (I had it a mid) but still have quite alot of movement. There's a little wearing where the seats interconnect but nothing to indicate that this much movement should occur.