i am 48 year old female, with a trek hybrid bike. my problem is that when i finish riding, and i stand up, i have intense pain in my tailbone, for a short amount of time, say 5 seconds. when riding, if i need to stand to pedal, there is intense pain as well. is this due to the position of my seat? or something i just need to get used to? thanks.

Same thing happened to me a few weeks ago - I am new to biking as well. Once I raised my seat - no more pain! Seat height should be about .83 x inseam, measured from center of crankshaft to top of seat. Good luck!

Have you ever broken your tailbone? After I broke mine for the first time (of 4 so far), I notice mine will ache for hours after a ride. Makes it real hard to sit in a hard bottomed chair. It's not particularly intense it's just a dull pain that persists. If you have fallen on your tailbone in the past, you may have broken it. It does anchor some major muscles which can pull on it and cause pain. At least that's how it was explained to me when the doctor told me that there wasn't much he could do to help.

I'm getting at times, a pain like on one side of the tailbone, like imagine the tailbone has a tendon or something on each side of it, it hurts on one side. It's becoming less and less as I ride, just like my knees hurting (got a single speed geared in 48-x16) has gradually faded away as my legs have strengthened.

I probably fractured my tailbone/center of pelvis in an accident I had years ago, I'm surmising that the riding now is introducing new stresses/loads to the area and over time that area will get stronger and the pain will go away, is it's largely gone now. It just takes time. Tendons etc take longer to grow and strengthen than muscles generally.