In the past, I've been lucky enough that the required spoke lengths for wheel builds have been close enough (< 2mm) that I could get by using all the same length spokes, which is a good savings for me since I can get a box of 100 at about half the price per spoke that I pay buying them individually from the LBS.

My newest build plan has spokes ranging from 164.3 on the drive side rear to 167.1 on the front. I'll be using double walled rims and brass nipples. Can I get by using the same length spokes? What would be the best spoke length to work with? I'm thinking of just ordering a box of 167s but since I have to order or travel about an hour to get any other spokes, I'm considering just picking up enough 165s for the drive side. Non-drive rear comes out to 165.9 on ProWheelbuilder's online calculator.

Here's another related question. I run my calculations through both ProWheelbuilder and FreeSpoke online calculators and almost always get slightly different lengths, sometimes up to 2mm different. ProWheelbuilder was recommended to me by a wheel building friend and so far it hasn't failed me, but just how big is the acceptable range of spoke lengths? As I always use double walled rims I tend to lean toward the long side as long as there is no risk of running out of threads before achieving the desired tension.

a bit long is OK, as long as you dont run out of thread . too short & head of nip breaks off .

I have one wheel where the drive side came out too long. I'm not sure why as all the stuff was from the spoke calculator and should have been correct.

They were almost fully tensioned, but not quite when the spoke topped out in the nipple.

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.

I would use 163 or 164 mm on the drive side rear (depending on the type of spoke). Running out of threads is not fun.

Stop playing yourself:
Sapim Stainless 14G Spoke at Dan's Comp
A quarter per spoke, any size. Includes the nerple. $0.40/spoke if you want DB. Liberate yourself from the tyranny of bike shop prices for spokes.

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.

You can file off the ends of spokes that protrude through the nipples in single wall rims. It's not pretty, but nobody will see it. The wheels on my PX10 are like that. They were built in the seventies and are still rolling.

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?

I use EDD, which is usually a few mm different than prowheelbuilder. I've never run into any discrepancies with what the calculator suggested and what i ended up needing for a wheel build.

So, I'm curious as to where you're getting quality SS spokes for less than a quarter each, including nipples? My usual move is, say I need 36 spokes at 268mm, and 18 at 266mm, plus 18 at 264. I'll get 40x268, and 20 each of the 266 and 264. That'll give me a few extra for "just in case", and it costs me $20 plus shipping. With nerps. I don't know about you, but i regard having an extensive "spoke library" as a dangerous thing, as I'll find myself trying to use the excess spokes to build some wheels, and then i try to find a frame for those wheels.... next thing I know, those extra spokes have snowballed into an extra bike....

Don't wait to lace and get a nasty surprise. Before lacing, test a nipple and spoke and determine how much overrun that combination will allow.

As for spoke calculators, they're electronic "calculators" and any will give very consistent results for any combination of entered data. However, there are adjustment factors built into each one's formula, and different calculators will therefore give slightly different results. So the key to getting accurate predictable results is to stay with the caluclator you're used to, and enter data the same way, especially the rim diameter, (ie. at nipple seat, vs. adjusted for desired end of spoke). Once you know how far and in which direction a result needs to be fudged to give you the desired result, it'll be the same for every calculation using the same methods.

Thanks FB