See map - anywhere there is a street crossing.
Easy - flat.
Fast cycling is not appropriate on the Brock Trail.
The waterfront section of the trail can be busy with pedestrians in nice weather at all times of the year, and some segments are narrow with tight corners and poor sight lines. Walking one's bike is highly recommended along the watefront section.
The Brock Trail is a shared/multi-use trail threading its way across Brockville's downtown and following Buell's Creek north from the waterfront.
The trail is documented under Heritage Walking Tours in the Hike the Arch section here.