Skytoproberts, you might think about coming up to Tinicum Park, Erwinna, on October 15 for the Central Bucks Bike Club's Covered Bridges Ride:
http://www.cbbikeclub.org/?body=cove...fd461b8f01c89c. There's a flat 20 mile ride, with a rest stop about half way, where you can take a break if you need it.
Later, you might also check out CBBC's "D" rides (I lead one D ride each month), for some cycling companionship and to learn some new roads and skills.
leob1 mentioned the NJ side: the NJ bike path doesn't end at Lambertville, but goes all the way to Trenton, I think. Before the flood damage, the PA side used to go all the way from Morrisville to Easton. Skytoproberts, you can vary your route by crossing the river, say at Washington Crossing.