Mountain Bike Earrings, Bicycle Earrings, Cocobolo Wood, Wood Studs, Biker Earrings, Gift for biker, Peddle bike earrings, Custom Studs. At Northern Grain, we make handmade, natural and eco-friendly wooden jewelry including wood stud earrings, dangle earrings, wood earrings with designs, wood cuff links and tie tacks. All of our items are made out of local wood or reclaimed exotic wood. We are located in Michigan's beautiful Upper Peninsula and make all of our products by hand.