Today I went to Diablo Freeride Park and after about 12 runs, my chain kept popping out of my chainguide. Chainguides are supposed to prevent that from happaning. Why is my bike doing that? Its a blackspire DSX C4 and I run it on my Specialized Demo 9 Pro. This has only happened today and after I got the chain back on by the time I was half way threw the mountian my chain popped off again. Do I need a new chainguide or does my chainguide need to be adjusted and if I do need a new chainguide what would you recomend for my Demo 9 Pro?