what should I do when single track gets narrow There are some trails I ride on regularly and I've seen many people go each way. A few times the single track gets very narrow and I was wondering what should I do when I see a biker coming towards me? There is also an about 50 foot cliff on one side and a fence on the other so I wouldn't have anywhere to go. Should I turn around and go back to a section that was wider and let them pass? Otherwise the trail is too narrow and won't allow two bikers side by side.

Edit
I live in Orange County California

Any ideas?
Presuming you cannot see the other rider before entering the narrow section (if you can, wait for them to pass through), going back is not my first choice - as others have commented, if there's enough room to turn a bike around, there's enough room to get past - even if it means both dismounting. 

Given most riders are human and can communicate even if they speak a different language, some form of dialogue should quickly come to a solution that meets the needs of the specific situation and individuals involved. Its also rare for very narrow sections to last for more than a few yards - perhaps "backing up" to a passing place would be quicker and easier. 

If there is not enough room for the bikes to to be passed around, and its too far to back up.... you could offer to swap bikes and meet up next week, same place, same time...... Especially if his bike is nicer than yours.