Fort Stanwix National Monument is accessible by bicycle by way of the trails along the Erie Canal National Heritage Corridor. Fort Stanwix sits a mile from the original canal site, at the center of New York, and welcomes all travelers. 

Here are internet links of affiliated organizations to assist you in your bicyling travels:

Bicycle and Pedestrian Page
Herkimer-Oneida Counties Transportation Study

Erie Canalway National Heritage Corridor --official site

Parks & Trails New York

Western Erie Canal Heritage Corridor Commission