It has been quite a few years since the discussion on routes has been posted. I am looking for a route on paved roads or trails from Chicago to Madison to spread out over 2-3 days. Gravel might be okay depending on how rough it is. One bike on the ride has 23 mm tires without enough clearance to go much wider. Any suggestions?
I've done Chicago to Milwaukee several times, never done Milwaukee to Madison. Milwaukee is pretty much the half way point. The route is mostly trails, though not entirely. I mostly followed the Google Maps route though added a little distance by trying to stay as close to the lake as possible. Of course you can also ride northwest through the northwest suburbs and stick to mostly roads. I did the Harvard to Madison route a few years back and it was mostly on low traffic routes, though of course this route has you going up and down hills most the entire way.
+1 I've gone Chicago to Milwaukee and Milwaukee to Madison - along the Glacial Drumlin Trail - just make sure you buy the trail pass, it's cheap, but there were rangers ticketing some other bikers along the way