A while ago I went biking with the empty cart attached. Spot was walking along and for the downhill and faster parts I let him jump on the cart. It was a good test to see how well the cart works together with a bike.
When biking in between backyards I send the cart flying. One of the cart wheels impacted on a concrete pole that was laying on the side of the narrow path. (Good thing Spot was not on the cart) The cart got a beating but was remarkably ok to my surprise. Maybe it was luck but I think one of it's strengths is that is semi flexible. The ropes take the impact and not so much the wood. Awesome!