Indoor cycling will not cause pain or injury to your knees if ridden correctly, for beginners it can take some time to get accustomed to riding a spin bike. Incorrect seat height and distance can be a perpetrator of knee pain. If your seat is too low, your knees will begin to take on additional strain by failing to properly extend. Knee pain can also stem from bouncing up and down on your saddle during spin classes and low resistance causing you to have less control over the movement in your legs. Having your resistance too high can also cause you to place too much load on your joints leading to pain. Cooling down after your spin session, knowing your limits and proper riding ergonomics will help reduce the risk of knee injury.