um, i don't think i ever washed or lubed my chain in over 10 months and the gear sprocket is dirty as hell. should i replace it or clean it, can it be cleaned or am i SOL. i did however, finally buy a chain lube and it's fine, works fine, looks fine. i'm a lazy mofo, i know. yes yes i don't deserve my bike. but it is my baby, when moving anyway.