Also a new guy from NW Indiana, but hailing from Portage. Also ride a Schwinn; a 1980 three speed Collegiate. I've spent a few hours on the Porter County trails, as well as the trail in Hobart that connects to them (the Oak Savannah?) I think I go a bit too slow to meet up with anyone judging from what I've been reading in this thread. I average only about 10 mph and typically only ride around 10 to 15 miles tops.
If you aren't aware matchstick, the Portage Parks Dept. has a few offroad bicycle courses that tie into the Iron Horse Trail. I believe they can also be accessed from Imagination Glenn Park.
J White