1888a123_Beginner_Dirt_Bike___GICL_Wiki_Dirt_Bike_Parts_List_Function
[Part and Quantity] Handle Bars (1) [Part Number] DR70-136 [Materials] Main frame is metal, probably aluminum because it is light weight. Handles are rubber for a better grip. [Forces] Only forces exerted would be those exerted by rider. [Manufacturing Process] For main ‘U’ tubing is heated then bent into shape. Then horizontal bar is welded into place [Shape] Shape lends itself to comfort of use. Also shape leans itself to ease of production [Part Complexity] 3 [Function] 
Functional: Allows rider to steer the bike. Also gives rider something to hold onto while riding
Group 11 - Beginner Dirt Bike - GICL Wiki