Hit up the gravel loop towing my son in the trailer today. I was a bit concerned about some of the hills, and they were challenging with the trailer, but I made it. Two laps was enough for me, the GPS says 5.3 miles, but I thought each lap was closer to 3 miles, so I dunno. I was riding for around 1 hour. I would have liked to have gone longer, but the last hill really killed me. I was glad for the 185mm front disc brake going down some of those hills. With all that extra weight it was a bit sketchy at times. I didn't want to get going to fast because I wouldn't be able to stop that well, and I didn't want to launch the suspension-less trailer into orbit on the bumps and waterbars. 
All in all a fun day with my son.
All in all a fun day with my son.