Speedplay X series or Light Action?

[Batbike]

I would recommend zero over both X and light action. For many riders, the X series has too much float! While float is good for many with knee issues, a large amount of float can spell serious problems, especially for less experienced riders. Until you have developed the muscles to support your knees and to track in a neutral plane, too much float can lead to injuries.

I have X series and wondered if I am experiencing too much float -- I have used the X3/X5 for 4 years (because of previous knee issues) but started experiencing new knee problems last year. Someone mentioned my foot/knee position due to float, making me wonder if I needed to change to Zero with less float. What type of injuries does too much float cause? How do you know if you have too much float?

am I hyjacking the thread? ... sorry ... didn't mean too ... thanks.