Here's an alternate route from NYC to Albany for you to consider, even though it does add about 30 miles or so: Go north on the east side of the Hudson River. A significant portion of this is on bike trails and NYS bike route 22.
From the Bronx, go north on the South County / North County / Putnam Trailway which gets you to Brewster NY. 50 miles of mostly car-free bike trail riding.
From Brewster NY, head north on NY Rt. 22 to Wassaic and go on the Harlem Valley Rail Trail all the way to the end of the trail, then get back on NY Rt. 22 (NYS Bike Route 22) to continue north to New Lebanon. The HVRT is a very nice bike trail 30+ miles.
From New Lebanon, go west to Albany on NYS Bike Route 5.
Aside from a few odd spots, NY Rt. 22 has decent shoulders and traffic is lighter than roads closer to the Hudson River.