Chainstay protectors on a bike can protect your frame from constant ware from the chain, extending the life of your bike, and making it with a bike tube is free! This works on all frame materials too (whether that be carbon, aluminum, steel or whatever). You'll want to replace this every 2 years or so, basically wait untill it starts tearing up.
wet paper towel (optional)
an old bike tube (it can have some tears or patches on it)
Step 1: Getting the Tube Ready
The first thing you'll want to do is clean the chainstay(the frame bit, not the tube), using a wet paper towel. Then your going to want to prepare the tube. start by cutting the valve stem off, and cutting the tube in half. Then following one of the seams on the tube cut the tube in half. You'll end up with a bike tube that is about 2-3 inches wide and a few feet long. After you have that, cut the tube lengthwise again so that the tube is only about 1 inch wide.
Step 2: Wraping the Tube Around the Chainstay
When you start this step you will want to have the electrical tape near you, btw! When you start wraping the tube around the chainstay, you'll want to start by the crank set, and start as far back as you both can, and feel, necessary. For the begining you will only need to overlap the tube to get it to stay. You don't need any tape for this, but make sure there is tension over the start of the tube, you wouldn't want it coming out prematurely. As you continue to wrap, I always overlap the previous wrapping by about halfway, so that by the end there is a thickness of two tubes throughout the whole length. When you get to the end, I always go back a couple wraps, to ensure a good end, and while your holding on to the tube, cut the excess off. ( You don't want to lose tension in the tube)
Step 3: Taping the Tube to the Frame
Alright, here is why i said to keep the electrical tape handy. While holding on to the tube, tape around the tube making sure to wrape up the end well. While doing this remember that electrical tape is especially designed to stick to itself well, so be sure to have some overlapping going. And there you go!...you now have a cheap and easy to make chainstay protector on your bike.