Zip lines can be installed for backyard recreation or backcountry adventure. All good things must come to an end, so your zip-line system will need a brake. Whether in the backyard or the backcountry, brakes are an important safety feature for stopping a person's downward momentum at the end of the line. Install brakes on your zip line using an old tire and a few pieces of hardware.
Measure the thickness of your zip line cable and choose the corresponding drill bit and wire rope clamp sizes.
Find the horizontal axis line through the tyre's centre, and drill holes through either side of the tire along this line.
Thread the zip line cable through the tire until it reaches the termination point of the zip-line system.
Tighten a cable clamp on the inner side of the tire. Slide the tire back along the cable until the clamp is pressing against the inner tire. Attach the other two clamps next to each other and against the outer tire wall, opposite the inner clamp.
Before installing the tire, the termination point of the zip line should be installed to your chosen tree or post. The proximity of the clamps on the inner and outer sides of the tire should immobilise the tire from moving along the cable. A tire without a steel radial will be easier to drill through.