Looking for accurate grade information for Belmont Hill (Belmont, Massachusetts)
On yesterday's ride, I climbed Belmont Hill (Belmont, Massachusetts), starting from Belmont Center and riding up Concord Avenue. The first two stages seemed very steep. The only instrumentation I have for the ride is a Google MyTracks session, which recorded a maximum grade of 35% for that section. While the hill was steep, a 35% seems likely to be a random number. Does anybody have accurate maximum grade data for this hill (especially the first two stages). My legs know something happened, it would be helpful to be able to quantify that something with a little more confidence.
While I'm interested in this specific hill, comments about methodology or sources for grade measurements for Massachusetts roads, or road grades more generally, would be most welcome. How do you figure this stuff out?