Moped Army

i don't know what tiney take is but i was just saying that my freinds dirt bike has 2 things. a speedometer and an rpm gauge thats not digital. They both work by the same type of spinning wire. its a flexible cable that has a square wire inside. One goes to the tire for speed. the other to the engine for rpm. Oh my bike i have these weird covered up things i can;t tell what it is. maybe i could hook somthing up.