If you have pain in your sit bones after road biking, you most likely used a seat that doesn't fit your rear properly. The road bike seat you use needs to measure just wide enough to support your sit bones. If it doesn't, you'll experience pain following cycling, regardless of how soft or hard the seat feels. Women and men have different needs in road bike seats due to their obviously different anatomies.
Sit Bones Defined
Your "sit bones" -- technically, your ischial tuberosities -- are the two protruding bones that carry most of your weight when you're sitting. These two bones carry all your weight when you're sitting on a narrow road bike seat. The seat on your bike should precisely support those two bones. If it's too narrow or too wide, you'll experience different types of pain and discomfort, both during biking and afterward.
If your bike seat measures too narrow for your sit bones, all the pressure from your body's weight will press down on the soft tissue between those bones. According to cycling blogger Sheldon Brown, most sit bone pain occurs due to narrow bike saddles. If your bike seat measures too wide, meanwhile, your inner thighs and legs can chafe on the outsides of the seat, especially when you pedal quickly. You also may have sit bone pain from a seat that is too wide, especially if it contains too much padding.
In order to eliminate your sit bone pain following a road biking session, you should measure the width of your sit bones and purchase a new saddle that fits you better. To measure your sit bone width, you'll need a friend to help you. Sit on a hard surface, such as a low coffee table and point out to your friend exactly where your sit bones touch so that she can measure the distance between those two points. Then, look for a bike seat with pressure points that match that width. A professional bicycle fitter might be able to recommend a seat based on your measurements, plus help you make some of the necessary adjustments.
Fit for Women
Since most bike saddles are designed for men, women often have problems with saddle fit and frequently experience sit bone pain after road biking. A woman's pelvis -- designed for giving birth -- naturally measures wider than a man's pelvis, which means that a seat designed to fit men won't work well for women. Several manufacturers market saddles made specifically to fit women, so you may want to look at those. In addition, a professional bicycle fitter may be able to help you find and fit a saddle that will prevent the problem of sit bone pain.