Originally Posted by avatarworf
... We are in Turkey, heading for Syria and on to Iran. Haven't seen what I would imagine to be a decent bike shop for ages and don't expect to see one in the future. ...
When I was growing up, I didn't know how to cook. I worked out the basics of making peanut butter sandwiches, but that was about the extent of my culinary abilities. There was no need to go beyond that, my mom took care of the whole family.
When I went off on my own and lived without my "cook", I learned how to broil meat, bake, steam vegetables -- even how to shop for groceries. Obviously, you get to a point where you need to learn these things to survive.
If you head out on your own through Turkey, I'd say you've "left home" and need to know the basics to survive. You need to learn how to true a wheel -- maybe not up to the "5-star chef" level, but I'd consider basic trueing necessary mechanical skills on a trip like that.
First, you need a spoke wrench. Then you need an hour to sit down with your wheel. If you have access to internet sites on trueing, that can help. But it's just basic wrenching and common sense. Once the wheel gets so out of true that it wobbles into the brakes, it might take several passes to true it up, since you've probably got both side-to-side and radial adjustments to make. But as long as you get the side-to-side wobble corrected, you'll be able to roll.
You need a fixed reference to gauge the wheel wobble, as you spin it. I leave the wheel mounted on the bike and flip the bike over, rest the spoke wrench against the seatstay and position the spoke wrench about a millimeter from the rim. That's the fixed reference. Then spin the wheel, keeping an eye on the mm gap. You can see the spots on the wheel that wobble; tighten the nipple on the spokes where the wobble is, to "pull" the wobble back toward center. (That is, where the wheel wobbles to the right, tighten the spokes on the left side; the nipple threads are standard right-hand threads, so be sure you're tightening the nipples, not loosening! The nipples "screw down" onto the spoke.) Check the wobble on both sides. Keep doing this, swapping side-to-side, until you reach "adequate trueing" -- I aim for less than a mm wobble, but you may be satisfied with more.
A well-trued wheel needs more work than this (radial trueing, centering the rim, and making sure the spokes are all tight enough). You really should know how to do this on such a trip to ensure long life for your wheels. But the above description should keep you rolling until you find a bike shop.