I ride a 2008 Giant Suede (7 speed cassette) for recreation, fitness and commuting (1-20 mi. almost daily). The offset bottom bracket really works well with my knees. As I expand my distance and routes I am finding a need for a lower gear at times and a desire for more speed (my old legs can only pump so fast). From my research it appears that teh ony difference between my model and the Suede DX is the three ring crankset and derailer. Since I cannot afford a new bike, nor the labor for my bike shop to add chain rings and derailer, can anyone share advice on my adding the chainrings and derailer?