Abstract: Retention mechanisms for bicycle drive trains are disclosed. In some embodiments, a retention mechanism may include a backplate having at least one spur, at least one chain ring coupled to the backplate, and a slider coupled to the spur. The slider may be positioned between the at least one chain ring and a bicycle chain, and may include at least one track and at least one chain guide (e.g., an O-ring or ring component) seated in the track. The at least one chain guide may be configured to rotate about the track while applying tension to the bicycle chain so as to reduce friction and/or dampen noise.