I started climbing with chaps at the beginning of summer and have had no issues with comfort or mobility. The leg straps of a harness keep them close on your thigh and knee. And spikes, when worn, keep them around your knee and calf. Plus the chaps give a little padding to reduce spike discomfort just below the knee. I was expecting them to be a problem, especially in tight dense trees, but I was able to work with little restriction. Like eye, head and ear protection the chaps have become a standard on and above the ground. Even in the bucket. Funny thing is now my crew and I look like space men with bright colored ppe because I dare anyone to try and find a tree crew in my locality, and there are many including the municipal tree crew, that has even a pair of safety glasses among them. It's sad that we are the oddballs. You'd think that the local OSHA inspector, whose office is a mile away, would have a field day fining for violations. But that is another thread.