i pulled a trailer with my Trek 2200 for my son. So, the trailer can go on a road bike. I have clipless pedals as well and had no issues. The trailer was fantastic, I did feel the weight but since I had a triple, going up hill wasnt too difficult.

I started him in it when he was 12months and he loved it until I got him a bike for his 3rd birthday. Now he won't get in it, thankfully he can pedel his little trek at 9 m/hr! So, we ride together. He is now 4 and an avid cyclist. He even makes me put his bike on the trainer in the winter so he can train just like mommy and daddy.