I'm a fifty something avid road bike living in Florida. I'll knock off 20 -30 miles each morning on my road bike. I'd like to ride with my wife on occasion. She's got a tank of of bike, pedal forward, that she loves. It's like the turtle and the hare when we ride together. Then we have these two dogs with a combined weight of nearly 50 lbs. I'd love to toss them in a trailer and pull them behind. WON'T put a trailer on the roadbike. What should I be riding to pull the trailer; hybrid, cross, mountain? It's all on road riding, very flat.