Soreness is often the sign of a good workout, but excessive soreness and numbness after your bike ride could hint at a serious issue. Having the wrong bicycle saddle for your proportions and body type can lead to discomfort and numbness if the blood flow to your pelvic region becomes constricted, and that can be dangerous if it isn't corrected. Measuring your particular proportions and finding a seat that supports your weight properly can make your ride more comfortable, even after your longest rides.
Finding Your Proportions
Your weight should be properly supported by the bike seat on two bony protrusions in your rear, the ischial tuberosities, also known as "sit bones." These protrusions are uniquely suited to withstand the pressure and impact of riding better than the soft tissues between your legs. To find the distance between your sit bones and determine your optimal seat width, sit on a flat surface and feel for the two contact points in your buttocks. The distance between these points is your optimal seat width.
Choosing Your Support System
Bicycle seats come in a wide variety of thicknesses, foam densities, and materials. The best saddle for you will put firm, supportive and absorptive foam underneath your sit bones, with an empty space in the middle to avoid putting pressure near the genital area. More cushion is not necessarily better; having too much soft foam in the saddle could fill the space between your legs, redistributing your body weight onto soft tissue, which can cause numbness. Look for a cushioned, comfortable seat with which your weight is fully supported on your sit bones.
Saddle Shape and You
Your riding style will determine the best shape for your bicycle saddle. For a racer or competitive cyclist, a narrow saddle is usually best to prevent chafing during high-cadence pedaling. Since these riders take a forward riding position, weight is distributed evenly on the hands and rear, requiring less cushioning to remain comfortable. If you're a more casual cyclist, you may prefer a wider, softer saddle since your upright riding position will place more weight on your rear. Saddles are also available in between these two styles for a more versatile riding platform.
Hammock-style leather saddles are more traditional bike seats. Each is made from a single stretched piece of leather, which breaks in and molds to the unique shape of the rider when properly tightened. A hammock style saddle can eliminate a lot of the pressure points that can cause numbness. Such seats are extremely popular for long-distance cyclists and cycling tourists. A leather saddle comes at a premium price, but the comfort can be well worth the investment.