pretty sure my last rear wheel build was something like 285mm ds, 286mm nds so obviously used 286 all round. Different hubs flanges, offset rims etc etc
I’ve never had any issue with DT spoke calculator but I want to upgrade some unusual straight pull hubs, no idea how to work it out for that sort of thing.
Well I’ve never done straight-pull, but…
It appears from the internets that straight-pull spokes are measured from where the bulb on the end starts (ie the end of the straight bit). Though I haven’t found a manufacturer’s drawing of this. If that is true, you need to measure your hubs accordingly, ie measure the flange hole circle diameter with reference to the outer end of the surface against which the spoke butts (and don’t correct for the diameter of the hole itself). If you were being picky, you would do two calculations, one for the inner spokes and one for the outer spokes (different flange offsets) though splitting the difference would probably do fine.
Well that’s how I’d do it.