Here's how to repair a chain tool free and can be used trail side
Step 1: Step 1
For this repair we will be using a master link. These are very inexpensive and will get you out of a pinch. Put the chain back through the derailer if you need to and then add a piece of the master link to each side and lightly attach them. Once they are attached give it a good yank and it will lock in. Once it is locked in you are ready to get back out riding. If your chain loses a few links when it breaks that's okay because most of the time there are a few extra links so you can shift. Eventually you may want to consider replacing the chain but this will get you back home. Comment any questions you may have.