I'm having some trouble with this decision, and can't find much online. I'm rebuilding a gear hub into my Xootr rear wheel.

Looking at the photo posted by forum member BruceMetras in the following post:

http://www.bikeforums.net/showpost.php?p=5875127&postcount=1411

http://farm3.static.flickr.com/2002/1937296727_24822edfaa_b.jpg

...it looks like a 2-cross lacing pattern works pretty well. But according to Danny Epstein's spoke length calculator on Applied Thought (http://www.appliedthought.com/danny/Spoke/SpokeCalculator.html), a 406mm rim laced 2 cross to my gear hub (a Sram i-Motion 9) results in only a 50° spoke pull angle.

3-cross gets me around 70° and 4-cross is close to 90°.

I've been under the impression that the closest I can get to 90 degrees, the better. But I understand there may be some limitations to 3x and 4x laced wheels when combining hubs with large flange diameters and small diameter rims. Is there any (numerical) way to better predict these conflicts?

The dimensions of the SRAM i9 aren't too much different from Shimano's Nexus / RedBand / Alfine or SRAM's Spectro series, so I figure they can all be lumped in to one general category.

BTW, if anyone is curious: I opted to re-use the stock rim the Xootr Swift ships with. I emailed Xootr on this, and was advised the rim is a JetSet CH-180 (http://www.jetset.com.tw under the MTB section). Naked, mostly cleaned of road grime, and with a not-too-worn brake track, the rim weighs in at 335g on my digital scale. I've measured the ERD at 393mm using the "two spokes, two nipples & a caliper" method. Stock spokes are 182-183mm / 187-188mm 14ga (2.0mm) straight / unbutted.

So anyhow, what say you? Is 2x lacing it? 3 cross or 4 cross possible?

Hi Nate! I have previously been impressed by your work (on mtbr?). Nice to have you over here as well.

Anyway, smaller wheels suffer less pedalling torque at the axle due to the smaller wheel diameter. So there is one plus point.

On the negative side, higher cross lacing results in more acute angles where the spokes enter the nipples, and they tend to break there as a result. You can see those angles on Bruce's wheel above.

So you are looking for a compromise between higher cross patterns and less acute rim-spoke angles, and 2-cross is the way to go. For my 16" wheel the lacing is 1-cross.

But since the torque is lower, having lower cross lacing is cancelled out.

Thanks for the reply.

I just got back with a visit from a wheelbuilder. I brought along the picture of Bruce's wheel. He told me the exact same thing, pointing to the angle at which the nipples are protruding from Bruce's rim.

On the Danny Epstein spoke calc, nipple angle has been on his "to do list" since the first time I used it. I guess that would be the data point I would be looking for to steer me towards the right lacing pattern on future builds.

Anyhow, we'll see how this all turns out. I've got a handful of 164mm spokes. Hopefully my ERD measurement was close enough for this to all go well.