Please call my mistakes out: Planning to build my first wheelset

[Yoln]

Hi,

I'm planning on building my first wheelset and I'd like your opinion on the components and choices I am about to make.

Use: Disc brake wheelset for racing and all-around riding. Definitely some sprinting and high-torque efforts planned. Strong preference for lightweight wheelset
Myself: 66kg/145lbs rider
Pairing: tubular tyres, Campy 12s cassette, 160mm rotors

Plan:
Rim: LB AR45 (Standard 28H rear / Flyweight 24H front)
Spokes: Sapim X-Ray (potentially Sapim CX-Sprint on rear drive-side)
Lacing: 2X
Nipples: Sapim Alloy (Or Sapim upside-down alloy)
Hubs: Carbon-TI Straight-Pull

Couple questions for you:
- Does the plan seem to fit the usage?
- What do you think about 24/28 combo in terms of stifness? What about the extra stifness from CX-sprint? Any better recommendations on spokes choice (I was aiming for light and Aeroe with a decent stiffness)
- What about spoke holes? I love my campy without holes, and I've had mixed experience with air leaking rimtape in the past. But sounds like a massive PITA to build a wheel without wholes, and I can't find many instruction on how to do so (using Sapim upside-down nipples for example)... Let alone for my first wheel build... Anyone here has experience building holeless wheels?

Thank you!

[alcatraz]

Carbon ti hubs don't come in 28h centerlock. It's 24h or 6-hole I'm afraid.

You could try cx-ray first and change later if you feel them flexy. Or do cx-sprint on DS rear.

With your weight you could do flyweight rims all around.

The rim shape, bladed spokes and internal nipples, are going to provide aero performance.

[Yoln]

Carbon ti hubs don't come in 28h centerlock. It's 24h or 6-hole I'm afraid.

You could try cx-ray first and change later if you feel them flexy. Or do cx-sprint on DS rear.

With your weight you could do flyweight rims all around.

The rim shape, bladed spokes and internal nipples, are going to provide aero performance.

Thanks, 6-holes indeed for the Carbon Ti 28, good call!


What is your view on difficulty to build a holeless wheel? I need to have all the nipples go through the valve hole if I understand correctly, and using a vacuum cleaner and some cotton wire is generally the way to go, correct?

[alcatraz]

I've never built one myself but I'd probably thread a piece of a spoke into a nipple and then pull it in place with a magnet. Some rims are rough on the inside and as such it could get stuck a lot depending on rim type, but it shouldn't bee too much of a problem.

If it were my first wheel I ever built with those hubs I'd be a little concerned to get the spoke lengths right. I guess I'd put some tape on a few of the spokes at a certain distance away from when the nipple is flush with the spoke end. That way I can measure after it's been built to ensure I got proper engagement.

I suggest to get a spoke key with three corner engagement (or what the hell it's called). The kind that only holds on two sides of the nipple, isn't that reliable for high tension or aluminum nipples.

[alcatraz]

Semi-internal nipples (like pillar dsn) portrude less and could save a fraction of a watt if internal isn't possible.

Also some spokes/lengths have longer bladed sections than others. The more bladed section at the nipple, the faster it should be. I've ordered the same spokes twice and got completely different shapes. One set has 5cm (!!) round section and one has only 15mm or so.

The rim shape is everything. Ask existing owners for closeup pictures of the rims with your favorite tire and size inflated. That way you can see if they mate well and produce a good aero shape.

[Aeo]

You can ask your rim vendor to pre-populate with nipples and secure with a zip tie stuck in each one of them

[eurostar]

I wouldn't mix spoke types. Do it all with Cx Rays.No need for anything heavier. But ignore me, Alcatraz is a better source!

[alcatraz]

Mixing on the same flange is a big nono. I've done that mistake a very long time ago. Oh look, this noname wheel broke a few spokes, lets replace them. Didn't work. (Even replacing with the same spoke from a different batch could fail)

Seeing as most wheels already have some kind of asymmetry (flange size difference, dished to one side) there's a difference between the sides even with the same spokes.

Sure if you would mix spokes the "wrong" way and put 4gr spokes on the DS side and 5gr on the NDS, it might aggravate an existing imbalance, but it wouldn't fail nearly as fast as mixing on the same flange.

It is however an experiment I'd like to see or do. To take a shallow alloy rim and lace it with same weight spokes of all different kinds, bladed, butted, non-butted, everything (major brands only). See how it holds up. Imagine trying to convert the tension readings and balance it. Ha!

[alcatraz]

No big brand wheels known for their sprint performance use 4gr spokes like cx-ray. The performance for your build is going to come from the well designed hubs and your low weight.

[eurostar]

To me this seems very ambitious for your first pair of wheels. People usually learn with very ordinary bits. Maybe you could dismantle a cheap wheel and build it again? Exotic ultralight bits are typically harder to work with and very easy to damage. The manufacturers tend to assume you've done it before, so the instructions might be vague and badly translated. Read them before you buy. If you're very patient and careful you might be OK, but expect it to take a long time.

[petromyzon]

Nothing wrong with the plan (you could even go 24h on the rear and I like the idea of CX-spint DS)
Could be difficult to execute. Ive built 5 pairs of wheels for my own use but never tried undrilled or straight pull. Still, what is the worst that can happen? If you are a decent mechanic and patient give it a go. The biggest risk is calculating spoke lengths wrong which is easy to do with SP and expensive with bladed Sapim.

NB do not build your own wheels expecting to save time or money!!!

[pdlpsher1]

I have no experiences with internal nipples (which requires rim holes) but I've built two sets of wheels with no rim holes. It's super easy. I did make some mistakes on my first set and cursed a bit. The mistake was not threading the nipples onto the spokes enough. While lacing the wheel some nipples fell off the spokes and into the rim cavity. It's a bitch to get the loose nipples out with only one valve hole. On my second set I thread the nipples onto the spokes so that I could only see a little bit of threads showing. Doing it this way none of the nipples fell off during the spoke lacing process. I used a short cut-off piece of scrapped spoke as my ferrous attachment to the alloy nipples. I have some strong magnets and I put the magnets inside a thin silk glove. This way the magnets won't scratch the carbon rim while guiding the nipples.

I've learned some valuable tips from Alcatraz in the past and I should point out two biggest ones.

1) Round down to the nearest 2mm (for example if it's 273.8mm calculated round down to 272mm) when calculating spoke lengths. Thin spokes will stretch and once it's up to the proper tension the spoke will be longer by about 1mm.
2) Never use Sapim Polyax with secure-lock. The secure-lock will prevent you from tightening the nipples enough to reach the needed proper spoke tension. Get the Polyax WITHOUT secure-lock.

As already mentioned you need some basic tools when using bladed spokes (pics below). The common nipple wrench won't work because they interfere with the bladed spoke holder. You also need a tensiometer and potentially a spoke tension calibration jig if the spoke you're using isn't included in the tensiometer calibration chart.

[alcatraz]

About that 2mm spoke length reduction thing.

I never really knew why that was necessary but after looking at some tension graphs of spokes I see that thin 4gr spokes do on average elongate by almost 2mm at around 120kgf. (if I'm reading these correctly). Maybe that explains it then.

I even reduce 120kgf spokes by 3mm sometimes. Probably because the spokes straighten out, nipples seat into the rim etc.



At around 100kgf we see about 1.5mm of stretch for a Pillar 1420 (4.3gr) spoke. (The results for the 1422 4.7gr spoke look impressive. It behaves much like the heavier spokes. I'm going to guess that it isn't quite 4.7gr, but a bit heavier.)

[Yoln]

Alcatraz, would love to see your picture of the graphs, but they seem to not be working

[alcatraz]

Ahh ok. That's odd. Check the attachment. It's the "breaking strength" graph on this page:
https://www.pillarspoke.com/psr-x-tra