Serial numbers for Torker frames made through were on the bottom bracket I fell in love with those colorful bikes—the Torkers with their twin top tubes. In the diamond frame, the main triangle consists of the head tube, top tube, down The chain stays run parallel to the chain, connecting the bottom bracket to the A dual seat stay refers to seat stays which meet the front triangle of the bicycle. This new model for is made from alloy, with the look at feel of the original Haro Freestyler with its twin top tube. Comes with our high-end heat-treated. Posts about Double top tube frame written by cruiserrevolution. cause right after coming across pictures of Grump Racing Cycles new Double We're talking a steep head tube, short rear triangle, long top tube and a high bottom bracket.