Telkwa

Sorry to keep asking newbie questions on the same subject, but does anyone do anything differently when setting up t/l on offset (or asymmetrical) rims? It's upsetting to me that the valve stem nut doesn't seat down evenly on my offset rims.

I'm trying the FSA offset rim washers. I like them so far. If the washer splits in two I'll be stuck on the trail and cursing my choices

This isn't a very good picture, but you can see the FSA washer in between the Muc-off stem and Duster Elite rim.

FBinNY 

When one ventures off the beaten path mechanically it's analogous to riding off track in an unfamiliar area.

You need to read the trail and react and improvise as necessary.

So, the valve doesn't seat squarely? Improvise a fix; maybe a rubber grommet, carve a spacer block and seal with silicone, maybe just a ton of silicone is enough?

So, all I can advise is to either stick to the reliable designs of the pros, or work to develop your own skillset, then the confidence to go without a map.

tyrion

The critical interface between stem and rim is on the inside of the rim. The nut and interface on the outside of the rim just has to pull the stem into the rim with a right (modest) amount of pressure.

That FSA washer sure looks like it's the right component for the job.

Telkwa

Understood that the sealing is on the inside of the rim.

I just don't like it that some of the valve stem nut is contacting the rim and more than half is hanging out there in mid-air. It's lame.

Darth Lefty 

The valve needs to be centered in the channel. The channel needs to be centered between the beads.

Diamondback got this wrong on their Blanchard rims in the late-2010s and it caused seating problems for the tires. They offset the channel to match the spoke drilling, and so there was no "shelf" on the narrow side between the channel and the side wall to guide the bead to its seat. When you hit it with the compressor the wide side would seat and the narrow side would flutter. I don't know if they have changed it since then.

Telkwa

I'm pretty sure the valve stem and the hole are in the center of the channel. That's not the problem. The problem is the asymmetric profile causing the nut to perch on one edge.

I'm surprised it's been so difficult to get a clear answer. This has to be a common situation.

well biked 

We 've sold a few FSA wheelsets that use those offset washers. It's been awhile, but I don't remember the presta nut contact with the top of the washer being a problem at all on tubeless setups. As stated before, the key is getting the valve stem's rubber grommet/seal on the other side of the rim FIRMLY into the valve hole. The presta nut is only holding that in place, not creating the actual seal. So the fact that part of the presta nut isn't contacting the top of the offset washer is really a non issue, or at least it was for us; I don't remember any problems with setting those FSA wheels up tubeless for customers.

well biked 

Also, I'll add that the outside diameter of Muc-Off valve presta nuts is slightly larger (I believe) than a more standard presta nut that comes with WTB, Stan's, etc tubeless stems. That's probably making the nut hanging in "mid-air" more noticeable.

fooferdoggie 

plus the muc-off nut feels sloppier or maybe because the nut threaded part is thinner?

FBinNY 

Sorry, but life doesn't offer clear answers.

When using products as intended, we can rely on the expertise of those who designed them. But when going "off book" we need to rely on our own expertise.

Since there are many gradations of not perfect, you cannot expect consensus, especially without a clear basis, or detailed specific info. - photos, measurements, etc.

Dean51 

DT Swiss makes tubeless stems for their asymmetric (offset) rims. DT Swiss web info acknowledges the stems are designed for their rims, but states they may work for others. 'Not sure what rims you have, but consider contacting the manufacturer for a recommendation.....if you haven't done so already.

Dean

Telkwa

While googling I saw some references to the DT Swiss offset stems. Didn't seem like they were available any more (?)

My rims are Bontrager Duster Elites.

Yeah, agree with well-biked. The Muc-off nut is a little bit larger. An O-ring is included in the Muc-off valve stems. There's a recess inside the Muc-off valve nuts that covers the O-ring as you tighten the nut. Like many of you have mentioned, the sealing is done inside the rim, not outside, but I liked the idea of the O-ring anyway.

If nobody has a problem with the valve nut perching on one edge, then I guess I should just move on. I've got very little experience with t/l and it's entirely possible that the things that trouble me are non-issues.

FBinNY 

The angle of the stem as it exits isn't an issue, even though the nut doesn't seat squarely.

The issue is that the base won't be square yo thr rim's inner surface, and that's where you may need added measures.

FBinNY 

The angle of the stem as it exits isn't an issue, even though the nut doesn't seat squarely.

The issue is that the base won't be square your rim's inner surface, and that's where you may need added measures to ensure a good seal.