The other day I was on Bushcraft USA and a thread started about wire saws. Almost none of the people posting liked them. I was surprised. I have had the same one for many years and used it on quite a few occasions. Now don't get me wrong it is not an everyday use saw. It's for emergencies. With that said, if you are going to carry a small wire saw you should practice with it. If you put the rings on your fingers and wrap the wire 180 degrees around a log and pull back and forth, you will break a wire saw!!! I have never done that to my saw. Maybe that is why I have the same one for many years. There are two ways to rig a wire saw. The first is the bow method. Real easy to make, but not the best option. The bigger the stick, hopefully, the more tension on the blade. This makes it easier to cut.
The best option is to make a Buck saw frame. The one in the pic took me about 10 minutes to make. The best part is that I used my new knife, I like!!!
As you can see ,it aint fancy!!! It will cut halfway decent though. The windlass at the top is what gives this design it's strength. Not as easy to make as the bow saw, but it works better. As always if you have question, ask and I will try to answer.