Courtesy The Bike House By DCist Contributor Lauren Evans Risen from the ashes of Chain Reaction, D.C’s erstwhile bike co-op, the Bike House is a small encampment behind Qualia Coffee on Georgia Ave., and consists of little more than an awning, a table full of tools, and the boundless enthusiasm of its roughly 25 volunteers. So small is their outfit that I probably would never have found it if I hadn’t stumbled upon their…