I need some advice. New to wheelbuilding, been truing my wheels before but never built ones. I'm building three sets of wheels (for my CX and roadie) with Novatec hubs and Sapim Race spokes. I can get the spokes only in even lengths (2x0,2x2,2x4,2x6...etc). I've been trying to decide the spoke lengths with the DTSwiss calc and Edd calculator, and I have a few questions regarding them. I think the basic question is, whether to round up or down? I've been reading about it, some people say to always round up (to have the maximum threads engaged) and other say to round down (to not to bottom out the threads). I'm in Finland, no LBS where to get the spokes so I have to order everything from Germany. Shipping is expensive, therefore I'd rather get everything right the first time.
The wheelset are: 1. Novatec hubs (F:A171SB, R:F172SB), Mavic A319 rims. Front 32h/3x, rear 32h/3x. The two calculators give me (Edd/DTSwiss)  F:296.4/292.2mm  NDS 294.9/294.7, DS 293.1/292.9 Should I get the spokes: F 296mm, NDS 294, DS 292?
2. Novatec hubs (F:A171SB, R:F172SB), Mavic CXP33 rims. Front 28h/2x, rear 32h/3x, 14mm nipples. DTSwiss calc takes 1mm off the spoke length due to the longer nipple, edd does not. Spoke lengths then are Edd/DTSwiss:  F:288.5/288, for this I suppose get the 288mm spokes  NDS:291,7/291, DS:289.9/289. Should I round the rear spokes up or down, NDS:290 or 292, DS 288 or 290? If I round down, should I get some 16mm nipples just to be sure?
3. Novatec hubs (F:A291SB, R:F482SB), KinLin XR300 rims. Fron 28h/2x, rear 32h/3x. Spoke lenghts edd/DTSwiss calc are:  F:280.2/280.2,  NDS 282.6/282.5, DS 279.4/279.4. Same question here as above: F:280mm is the right lenght, NDS 282mm I suppose, but for the DS 278mm or 280mm ? The erd used is 577mm, has anyone measured the XR300 and what were your results? I read somewhere that the erd can be 578 or even 579, that would make 278mm DS spokes too short?
What would you do? Any advice is appreciated.
