Originally Posted by Al1943
I'm familiar with your problem. I built most of my wheels with DT Revolution spokes and when converting the Park deflection numbers to kgf for the central part of the spoke, 1.5 mm, the conversion chart shows that I have 160 to 165 kgf on the driveside rear spokes. This is what it takes to get enough tension in the non-driveside spokes to avoid failure at the "J" bend due to flex, and at the same time have a centered rim.
I seriously question the technique of using the Park conversion chart and the skinniest part of double butted spokes to calculate the tension at the rim. My wheels have light weight rims, MAVIC Open Pro and DT RR 1.1, and aluminum nipples. After several thousand miles I've had no ill effects from the high tension, whatever it actually is.
Al
I'm not quite sure what you're saying here. The Park tension meter measures deflection. The thickness of the spoke not only affects the deflection reading, it also affects the actual deflection amount. So Park has made a chart that determines actual deflection, normalizing the reading for spoke thickness, then converts that deflection amount into a kgf unit.
Most experienced wheelbuilders I know go to rated tension on drive side, and leave the non-drive wherever it ends up, as long as it's taught enough not to go slack. This can be mitigated by using thinner spokes on the non-drive side, since they will be stretched more to get up to tension, and will therefore be less likely to go slack in a bump hit.
Too much tension on the drive side will crack the spoke holes. It happened to one of my Open Pros before I knew better.