I have a TREK 4300, that is slowly becoming something else, I have an MX PRO ETA Marz. forkand a Race Face DH crankset this bike is slowly becoming a frankenstein bike. My Q is, I have a prob with my chain, whenever I land a jump, gap, etc. my chain will sometimes jumpoff the ring. Would it be totally stupid to put a chainguid on my bike, the crankset is the Evolve DH, and has 2 rings. IF SO could you point me in the direction of a good guide, Im shooting for less than 200. thanx soo much.