Spoke length help (offset fat bike)

[p nut]

I'm trying my first wheel build. Decided to complicate things like I usually do and add a bit of challenge. The frame is a Surly Pugsley frame. It uses 135mm hub and the rear end is offset to the drive side by 17.5mm.

In determining the spoke length, do I just need to add 17.5mm to the drive side "hub center to flange center" measurement, and subtract from NDS?

I'm using this:
http://www.bikeschool.com/tools/spoke-length-calculator

Hub(X7):
https://www.sram.com/sites/default/files/techdocs/gen.0000000004375_rev_b_mtb_hubs_build_specificati ons.pdf

Rim:
http://www.kstoerz.com/freespoke/rim/282

So for NDS, I get 265.1, and DS is 264.6

Do you round it down or up when they're in between whole lengths?

Also, a good online resource for spokes would be appreciated.

Thanks.

[David Kirk]

If the rim's spoke holes are offset by the 17.5 mm then I think that doesn't effect spoke length at all. I think you just enter the actual flange-to-center numbers. The rim would be providing the offset and not any dish you'd be building into the wheel.

dave

[p nut]

Ah, ok. According to the link above, the Rolling Darryl rims spoke holes are off set by 12.5mm. So looks like a 5mm net variance.

[JAGI410]

You have the little red anodized wheel building adapter right?

[p nut]

You have the little red anodized wheel building adapter right?

Yes, but I don't have a truing stand so I'll just be using the frame.