Local bike shop bike shops have begun themselves to sell products online. A recent development is the introduction of brand specific stores from bicycle manufacturers such as Trek Bicycle Corporation. Other manufacturers, such as Specialized are strengthening their channels with "concept stores". According to the National Bicycle Dealers Association, in 2007 there were approximately 4,400 "specialty bicycle retailers" in the USA; down from 4,800 in 2005. Although they sold only 17% of the bikes, up from 16% in 2005, they collected 49% of the dollars, up from 47% in 2005. In 2004, the average specialty bicycle retailer had gross sales of $550,000 per
Tandem bicycle very same reason. Some argue that this produces a smoother power stroke, or that it reduces stress on the drive train because the point of maximum power is reduced to roughly half and distributed over the chainrings. Since the market for tandem bicycles is significantly smaller than the market for single bikes, there are far fewer tandem bicycle manufacturers than single-bicycle manufacturers. There are a few builders who specialize in tandems, as well as single-bike makers who offer tandem models. Current notable tandem bicycle manufacturers include: Tandem bicycle The tandem bicycle or twin is a form of bicycle (occasionally a