1888a123_Beginner_Dirt_Bike___GICL_Wiki_Dirt_Bike_Parts_List_Function
[Part and Quantity] Rear Sprocket (1) [Part Number] DR70-381 [Materials] Metal/steel for strength [Forces] Force of engine driving the chain which transfers force to drive the wheel [Manufacturing Process] Pressed into correct shape [Shape] Shape has multiple pegs evenly spaced to fit into the links on the chain [Part Complexity] 2 [Function] 
Functional: Connects chain to the rear wheel
Group 11 - Beginner Dirt Bike - GICL Wiki