Originally Posted by
NOS88
Part of good saddle fit has to do with your typical riding position. The more upright your torso is the more weight your "tailbone" must bear. As your torso leans forward it tilts your pelvis moving some of the weight off the tailbone. Looking at the link you provided it appears there's no easy way to move your handlebars forward. Is there any room to slide you seat back? If so, I might try doing that to see if it makes a difference.
I think this is a very important point. The OP's pelvis probably needs to rotate forward, off the tailbone, and the existing saddle may be fine if she does.
First, make sure there's proper leg extension, then drop the stem (i.e. lower the handlebars) as much as possible. If there's difference to be gained, it could help rotate the pelvis enough to alleviate the pain described.
As earlier suggested, moving the saddle back on the rails could help, especially if the bars are relatively lower to the saddle.
Like others, I'm of the basic opinion that going bolt upright in posture is not the way to gain comfort for riding. It may feel fine and 'natural' at first, but after just short rides, that comfort can go right out the window. While there are saddles and other means of achieving more upright comfort, if cycling for fitness is the goal, the OP would be better served to move towards a more tipped pelvis/angled back position.
Some pictures of the bike and/or pics of the OP on the bike would be much more helpful in troubleshooting the problem no matter what.