There are lots of things that are probably quite different about your TT Cruiser than your DF bike. You don't mention what bike you were riding before. Was it a lightweight road bike with high quality components? How does that compare to the 36 pounds (with no extras like water, tools, and a spare tube) listed for the Cruiser? You also have a much different gear range using the 20" drive wheel on your trike (18 to 90 gear inches). There is the physics of having 3 wheels on the ground and 3 sets of bearings and the larger frictional losses due to three instead of two wheels. When I got my first trike, a TT Wizwheelz 3.4 it took quite a while to get to the same fitness level I had on a 2-wheeled recumbent weighing just a few pounds lighter and having a much better gear range.