Of course there is a second site that should be cut out. When you have butchered the tire this way, it is time to ask yourself what to do with the tread of the tire. You can not cut the embedded thin steel 'textile' with a knife. But it works well to saw it with a very DULL metal hacksaw. Clamp the rubber between two bits of wood and saw close to the edge of the wood, where the rubber gets some support.
Each tread is 1,70 long. They can be put together lengthwise with an iron cramp. Thus they form a very strong flexible strip. Not difficult to find good use for this as well!