Rivnuts from Homestead,PA on 1/2/2020 9:58:49 PM:
The GAP/C&O trail is generally safe and crime free. Not unsurprisingly, the greatest risks to your bike and gear are in the largest cities, Pgh and DC. I carry a light-duty combo lock to use when my bike and gear are not within sight. When camping I lock it even it the most remote hiker/biker camp sites. Although it’s probably not necessary, it seems like a rational and simple precaution to avoid having to walk home.