Building wheels with XM819 UST. Spoke length, loctite, tightening?

[Wolfgang Weiss]

I'll be building a wheelset for the very first time with XM819 non-disc rims, Novatec A141SB\F162SB hubs with DT Swiss Competitions spokes but I'm not very sure about spoke length. I used Mavic spoke calculator and according to it I have to use 258mm for the rear wheel and 254mm for the front but how correct are those numbers? I know that UST rims are pretty tricky when it comes to building wheels so I'm pretty suspicious about those calculations.
Also which loctite should I use for the eyelets and how much should I tighten them? And are there any other things that I should know before building those wheels?

 

[klunkrider]

If your suspicious about the lengths, I'd measure the erd and hubs yourself (no, I don't even trust manufacturers to measure properly) and redo your calculations with a few different calculators and see what you get.

I had an XM819 that I stripped off a hub and rebuilt and I greased the nipple cups because stripping it had been a real pain with a lot of the cups quite seized and needing to be replaced.

 

[klunkrider]

To be clear, I'd always recommend measuring parts yourself. I've found dimensions in the wrong places (centre to flange distance listed as flange to locknut, left and right measurements for hubs mixed up or listed as being the same when they are very different etc) or just plain incorrect measurements from manufacturers, retailers and in spoke calc databases.

 

[Wolfgang Weiss]

I greased the nipple cups

But won't they loosen up with time when greased?
Yes, I'm going to take measurements myself as soon as my hubs arrive, but the question is how much should I trust all of those spoke calculators? I just suppose that the UST rims are a pretty special case and those calculations might actually be wrong or something. I don't really know.
Oh, and btw, did you ride them tubeless? How well did it work? I got those rims for this very reason, I'm planning to buy a pair of Race Kings and set them tubeless.

 

[klunkrider]

Didn't ride it tubeless I'm afraid nor did I have it around for long enough to see if the cups loosened.

I guess its like some people grease the threads on the spokes, others use spoke freeze or linseed oil to lock them in place. As a mechanic I find it really annoying when nipples are seized on spokes. It's bad enough when it's corrosion but when it's been someone's intentional choice to put a product on there to do that it really boils my piss!

As for trusting spoke calcs, that's why I say to do the calculation on a few different calculators. Then you can take an average.

I tend to use Leonard and Pro Wheel Builder and there's never usually any more than a few tenths of a mm betwetween what they spit out and now that I have my erd measuring technique and an idea of which way I want to round (up) it's been a long time since I bought spokes in the wrong size.

The calculator websites are just performing a/the mathematical equation to get you a spoke length. That forumla seems to be pretty readily available if you'd prefer to do the maths yourself but the calculators I mentioned seem to do a goo enough job for me at least.

There really shouldn't be anything special about the XM819, the ERD is the ERD. Just make sure the nipple cups are fully screwed in when you take your measurement and when you build the wheel I guess.

 

[wynne]

I work as a wheel builder.
We always prep the spoke threads by dipping them in boiled linseed oil. We also grease the nipple where it contacts the rim for the spokes which will be at highest tension (drive side rear and disc brake front) - this helps to ease these spokes up to tension.

When finishing wheels we put a drop of loctite into the nipple. This is not intended to lock it in place but to create a barrier that prevents the ingress of contaminants that can lead to things seizing up and nipple corrosion.

 

[klunkrider]

I work as a wheel builder.
We always prep the spoke threads by dipping them in boiled linseed oil…When finishing wheels we put a drop of loctite into the nipple.

I hate you!

Only kidding, done right it’s probably fine but I’ve had to try and salvage wheels where the nipples have been drowned in red loctite!

 

[wynne]

I hate myself sometimes.
The loctite we use is green, so it wasn't me.

 

[Takingabreak]

DT Swiss spoke prep is red...