Originally Posted by
Proximo
His definition of "optimum tension" for the drive side spokes is as high as the rim will allow and still react properly to tension tweaks.
A thorough reading of Schraner's very fine book will reveal that he is a firm believer in the use of tensiometers. He goes so far as to admit that, after starting to use this tool, his own "sense" of tension was not very accurate and would vary from day to day. I have talked to Gerd and he says to use a tensiometer and consult the rim manufacturer to get the maximum allowable tension for drive side spokes.
Rears should be built up to the point where the drive side tension is at, or near, the rim manufacturer's max spec. Rounding, lateral truing, and dishing, should be going on, incrementally, throughout the process. If you do it right, the last tweak you should be making is the final dishing. Smart wheelbuilders try to get the rounding out of the way early in the build. Rounding often takes big adjustments. Once it's good, the lateral truing and tensioning don't often change the rounding by a lot. Then you incrementally increase the tension in several steps to get to the maximum. Again, a smart wheelbuilder will do lateral truing AND dishing in the same step. It's a little bit of a chess game. You need to look ahead to see where you want to get to and, by doing so, can kill the truing and dishing at the same time. That's a bit advanced for a lot of people, so the simple method is to do rounding (radial truing), lateral truing, dishing, increase tension, and stress relieve. Rinse and repeat, rinse and repeat, ...
It should take three to four iterations of those five steps to finish the wheel. A well built rear wheel will have all the drive side spokes within 5-10% of each other. You are going to get the biggest variations on either side of the seam, so don't stress out about that. Most wheels are going to have one high tension and one low tension spoke. Rims are not perfect.
If you want to build consistantly good wheels get a tensiometer and dishing gauge. That business about flipping the wheel over in the truing stand is pretty "iffy" in my opinion. I use a Park TS2 all the time and the wheels move in the stand almost every time you turn a spoke. Trying to use the stand to determine the dish just slows you way down. You can get a decent tensiometer and dishing gauge for well below $100. Once you use a dishing gauge the first time you will become a believer. Well worth it if you're going to be doing this in any volume.