Originally Posted by
andr0id
I was able to make it work by grinding a slot in the middle of a screwdriver to get the last few turns in.
Kind of a pain in the butt, but I didn't want to wait a week/10 days for another round of spokes.
Originally Posted by
FBinNY
The amount of leeway depends on the thread overlap in the spoke and nipple, and on the type or rim.
You need the spoke to engage the head of the nipple by at least 2mm. That leaves another 2mm or so to the top. When building double wall rims you can let the spoke extend above the top of the nipple with no issues. However, the amount that nipples thread down on spokes varies with the nipple/spoke combination. Some run out of thread and jam within 1mm of the top, others allow overlap of 5m or more.
Also note that when building single wall rims, the tube will be resting on the tops of the nipples, so you can't have spokes protruding.
So the amount of leeway varies from a low of 2mm or so, up to 7mm or so under some conditions.
Ideally, I like to get my spoke lengths so that they come out about even with the bottom of the screwdriver slot in the nipples. Reality is that I seldom get that close. I've got a screwdriver that I slotted in the manner andr0id mentioned and it works well. By going a little long (rounding up on lengths) and using the same lengths for the non-drive and drive side rear, I've almost always used the slotted driver for at least the last turn or so and sometimes have had up to a mm protruding past the top of the nipple. As FB said, no problem with double-walled rims. So far I've never run out of spoke threads before reaching tension but this build has a wider range between the suggested short and long spokes than my previous builds (26" MTB instead of 700c road). FB said that the range is about 2mm on the low end and up to 7 under certain circumstances. The range on this project is about 3mm so WTH I'll just go with the ones I know I'll need for the front and am 99% sure will work fine for the non-drive back. If they bottom out on the drive side, I'll be making a trip to the LBS.
Thanks for the advice. Anyone have thoughts on which is the most accurate online calculator?