Wheelbuilding / Wheel Building / Wheel build help

Need advise on parts choice, now have:
Zipp 303 firecrest tubular rim (285V4) 24h
American Classic Rear Track hub 24h 2.5mm spoke hole
Planning to order:
Sapim Super CX ray spoke
Sapim alu nipple 15G 12mm
and my questions are,

1. What is the real ERD of Zipp 303 firecrest tubular (285V4)? Zipp website said 555mm but wheelbuilder.com said 549mm, the 6mm off make 3mm spoke length difference in calculation.
   
2. The Sapim Super CX ray say in the description they should be used on hub hole size 2.3mm or less, will this cause a problem using them with 2.5mm hub holes?
   Thanks
   

I use this method for ERD https://m.youtube.com/watch?v=DVpW3Kd1HgI

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Sapim Super CX ray

Don't, especially on a rear wheel. The weight saving is irrelevant, certainly not enough to make up for the reduction in stiffness and durability. Use regular CX-Ray and your worries about the spoke hole diameter disappear too.

A new grade of stainless steel enables Sapim to reduce the diameter of the spoke, whilst increasing its strength and fatigue resistance. Effectively, the CX-Super is 17% lighter than the CX-Ray and its strength is increased by 120N in the middle section versus that of the CX-Ray.

Despite the spoke hole problem, I guess the super cx ray is better and stiffer in description?

I guess the super cx ray is better and stiffer

It can't be stiffer, for practical purposes all steels have the same elastic modulus.

I've been offered a pair of Phil Wood HF 32h hubs, for a good price.

The front has been laced radially: is this any cause for concern?

Phil warrants all his hubs to be suitable for radial lacing. The spoke bend tends to dent the flange, so it's best to stick to the same lacing pattern if you rebuild an old hub into a new wheel.

Thanks, but 32h radial?

Meh.

32h radial?

I agree, it does look a bit wank

Don't get the Phil hub hype. My BDW Novatecs haven't been touched in forever and still spin perfectly.

I wouldn't bother normally, but I've been offered them in exchange for my labour.

Might just flip 'em and cash-in the hipster tax.

This is probably a daft question, but I always ask them so I'll continue:
novatec cxd hubs

This is the complication:
I have a SS pompetamine (disc brakes) and a CaadX (canti mounts).

I'd like, ideally, to be able to use the wheelset on both. I'd also like to try them tubeless.

What, if anything, will fill this requirement?

Velocity rims are all (I think) tubeless compatible. A23, Dyad and a bunch of others are wide and have machined sidewalls. Stans Alpha something has a machined sidewalls and can be run tubeless too.

DT Swiss R460 also fits the bill I think...

And if i wanted to be really silly, is there a carbon rim that could do this as well?

(pipe dreams)

Is Caadx not 130mm OLN and Pompetamine 135mm?

see. That's why I ask ALL the daft questions.

dream first, specifics later.

135mm hubs went in my canti CAADX just fine. If anything the rear end was slack on a 130mm hub.

Dreams:
A wheelset that can be used on both pomp and caadx with tubeless carbon rims and disc hubs.

Would settle for:
A wheelset that can be used on both pomp and caadx with tubeless alu rims and disc hubs.

Will probably get:
A wheelset for the pomp with disc hubs and tubeless rims. Whatever is cheap.

Still clueless about where the 4mm was calculated wrong - but here they go

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Rim suggestions for a heavy duty, two wheeled cargo bike rear wheel?

26", 36h, disc brake, about 2" tyre. A couple of rims I've looked at are DT FR600, Mavic EX325 and Mavic EX721. Might prefer DT. Not that I've built a huge number of wheels, but the couple of builds I've done with DT rims have been among the easiest.

mavic d721's if you can find an decent pair, the predecessor to the ex721's

The stiffness of a spoke though is dependent on its cross sectional area. A very stiff rim would have to be used if super CX spokes are used. Given the expense of the spoke though I dont think they are worth it. Weight saving is not huge.

I use a average weight of 440g for the OP but that was determined a couple of years ago. I stopped building with them because they are not popular so pointless holding stock, they wear out quickly (typically 5000 miles or so for the customers I know) and the resulting wheel even with 32 spokes is not overly stiff unless plain guage spokes are used and a 10 speed shimano hub then it is adaquate. You cannot have a light wheelset with the Open Pro rim that is also stable.

With the Ryde Pulse sprint you do get a rim with a thin brake track but it is wide with all the benefits that brings. also the rim is alot stiffer meaning a 28 spoke rear with sapim laser or CX-ray spokes is a stiffer wheel than a Open Pro 32H with plain gauge spokes and a shimano 10 speed hub. So in my view it is worth the extra money and you can actually have a light wheel as well.

The Open Pro was a fine rim 10 years ago but things have moved on. If a new version came out then maybe it would be a benchmark again but the DT Swiss R460, H Plus Son Archetype and a couple of Kinlin rims have that crown now for a wide 450g-485g rim which are also wide. The Ryde Pulse Sprint' brake track is a bit thin to make it an all weather rim. Also Hutchinson tubeless tyres cause a big tension drop but they do that to other rims too.