This degeneration of the cartilage in your knees usually is marked by pain beneath or on the sides of your kneecaps. You might also experience swelling, and in severe cases you can hear the bones grinding.
Treatment can include decreasing activity, icing for swelling and aspirin.
But if you like to bike cheer up. That's one exercise that might just ease your pain. But take some precautions: Stay off the large chain ring, avoid hills and adjust your saddle so your knees are only slightly bent at the bottom of the pedal stroke.