Hubway stations were unveiled in Brookline, Somerville, and Cambridge this morning, officially expanding the bike-share system into the Boston suburbs.

Hubway’s “Rolling Launch Party” gathered in Central Square at 11 a.m., after ribbon cuttings at Brookline Town Hall and Somerville Town Hall. City and department officials and riders met in front of the post office to hear remarks from Cambridge mayor Henrietta Davis and delegates from Boston and the several organizations involved in Hubway’s expansion.