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
Bicycle and motorcycle geometry axis intersects the ground. The measurement is considered "positive" if the front wheel ground contact point is behind (towards the rear of the bike) the steering axis intersection with the ground. Most bikes have positive trail, though a few, such as the two-mass-skate bicycle and the Python Lowracer have negative trail. Trail is often cited as an important determinant of bicycle handling characteristics, and is sometimes listed in bicycle manufacturers' geometry data, although Wilson and Papodopoulos argue that mechanical trail may be a more important and informative variable, although they both describe very nearly the same thing. Trail is a