Originally Posted by
BCRider
Keep in mind that I just picked the rim ERD and flange drilling diameters (the PCD?) out of thin air for the sake of this diagram. It's not far off some rim size options but there was no attempt to match any known rim. It was all just about the spoke patterning. As such the ERD shown is 576mm and the flange drilling diameter is 67.2mm's. Also there was no attempt to account for the cone angle of the spokes. What you see is just a purely flat pattern. The only reason to set the "hub" and "rim" to sizes roughly true to life was to see roughly how much the spoke lengths would vary in a real life laceup. So the final true numbers for real life parts may or may not be within the same 2mm variance.
Of course, but it's extremely helpful in understanding what might make the LRLR patterns work. Even a 4mm variance (ie +-2mm) should be sufficient as spokes traditionally come in only 2mm increments, not to mention variations in spoke head placement, rim drilling (ie alternating offsets), etc.
In any case after some thought I decided this will indeed be a variation around the Rinard calculation...because the hub is just a slightly rotated version of that (with one spoke a little longer and the other a little shorter). So I'm ordering some spokes to try it out and if all goes well I'll probably get some nicer DB spokes to do both wheels (the LLRR pattern is fine for a perfect rim, but one of the advantages of a spoked wheel is to correct such imperfections).
Thanks again.