A few questions about SP spokes for a new build.
Firstly, Musson’s spoke calc gives me 278.2 and 278.6 – should I order half 278 and half 280 or all 280?
bike-components.de have got spoke sets with Alu nipples. Previously I have always used brass nipples because of the steel/alu interface. Is this a problem in the real world?
Is there any advantage in spending the extra on bladed spokes?
And finally, any recommended (cheap) suppliers?
Thanks.

All 278mm and I would avoid using alloy nipples if you plan on riding the wheels anytime when there’s an ‘R’ in the month, particularly salty roads, or use a corrosion inhibiter like ACF50. You don’t say whether they are road or MTB wheels? Bladed spokes can help a little on the front and with low-spoke count wheels as they can be stressed higher, but don’t give much benefit on the rear except cost more to replace. Bladed spokes are also a bit more fiddly to build with as you need a spoke-catcher to keep them aligned / stop twisting

Previously I have always used brass nipples because of the steel/alu interface. Is this a problem in the real world?

I had to rebuild a pair of wheels after the alu nipples starting corroding and cracking. I went back to brass after that.

278 – I always go shorter, because spoke calculators don’t account for spoke stretch which can easily be getting on for 1mm. The last wheel I built had bladed spokes and alu nipples, but then that was a semi-aero roadie wheel and I’m a weight weenie tart. For MTB wheels where aero is much less of a factor I’d never use bladed spokes (they don’t really have any advantages beyond aero) and despite using alu nipples on a couple of my own builds I’m well aware of the downsides and wouldn’t recommend them to anybody else asking.

And finally, any recommended (cheap) suppliers?

Rose seemed to be cheapest of the Germans when I ordered last week. That was for silver Dt Competition with brass nipples bought separately.

Alu nipples are shite tbh.

No advantage to bladed spokes imo, yes there’s an aero difference but mountain bikes and riders are about as aerodynamic as wizbit. They do tend to be high quality spokes though (like, the CX-Ray is literally just the same spoke as the Laser, squished flat- but the extra forging makes for a stronger spoke. So, it’s not all about the aero.)

Got my DT Aero spokes from Bike24 iirc. Used the aluminium Squorx nipples that came with my ex471 rims, no problems with them.

There’s a lot of misunderstanding about that – I’m not accusing you, just clarifying. In real terms it should make no difference at all, as spokes will break at the bend not on the flat part (I’ve broken a few CX-Rays on a wheel there, not sure if it was a bad batch of spokes or a bad build 😳 ) Most people also misunderstand what a stronger spoke means – it simply means it will take more load to break the spoke, nothing to do with the wheel strength (Sapim Race spokes with a center section which is less strong but stiffer will make a stronger wheel).

I’ve used Laser spokes on an MTB build – don’t see any advantage to CX-Rays for that.

I use lasers too- though it turns out Sapim recommend against it for disc wheels, I didn’t find that out til after I’d been using them for a while so I just carried on 😆

But, I’ve never broken a spoke at the bend, for me they always go either in the threaded portion, at the rim end of the butting, or wherever the foreign object whacked them.

Alloy nipples do rot and fall apart but for me I still use them on my own builds as I’m a full on weight weenie and it’s my own time to waste if it ever causes a problem.

For customer wheels we always recomend brass , my current choice is Dt squorx brass pro lock
And on carbon rims alloy nipples are even worse than on alloy ones

My disc wheels have Lasers – though I knew Sapim didn’t recommend them before I built. I figured that they recommended CX-Rays which are the same thing for all functional purposes and as I’m an engineer I knew better 😉 Surprised about your breakage locations, I think I’ve only ever broken them at the elbow, though that’s where they tend to go due to fatigue, and the thread is the second weakest point.

+1 – though the wheel I just rebuilt after 5 years I reused the alu nipples as they were fine. That’s my best road bike wheels though, so at worst they only get wet roads in summer.

Thanks for all the answers, chaps. Looks like 278mm DB SP spokes with brass nipples will do the job.