ArgoMan 

Hey all. Has anyone run into wheels that have small tubeless valve stem holes in the wheel, such that it's very difficult to push the stem completely through the wheel? I recently attempted to mount tubeless tires on a set of used DT Swiss 1400 ARC Dicuts, only to find that it was very challenging to push the stem completely through, so as to make it totally flush with the inside of the wheel well. In fact, I wasn't able to. I guess that I could have forced it, but I gave up and decided to let a "boutique" bike mechanic who I recently met do the job for me. I'm super busy, not the best mechanic, and the bike is for racing. So I thought it best to have a pro handle this stuff. But he also found that the holes were too narrow and recommended that I go with tubes. He even suggested that the wheels are not tubeless ready. I contacted DT Swiss, and was told that all the 1400s are tubeless compatible. I really want to ride tubeless, so I got to thinking, "has anyone else ran into this problem?" Here's a link to a depiction of the type of stem I was using; notice how the base has rubber that runs up the stem for a bit. It was that rubber portion that was too wide. Any info will be greatly appreciated:

https://www.biketiresdirect.com/prod...RoCl0YQAvD_BwE

maddog34

i have a couple tubeless stems in stock... both have TAPERED seals at the inner base...

and find a better mechanic. installing the straight seal type would require putting a small chamfer on the rim's inner stem hole lip.... which would also be compatible with tapered seal stems....

ArgoMan 

Yikes, thank you! Now, to be sure that I understand your lingo (I'm not a mechanic), when you say "tapered seals at the inner base" I assume what you mean is a stem valve with a rubber based that tapers off toward the top of the stem, sort of forming a cone? That's the kind of stem that I have used in the past. The stem I tried to use this time had that "anvil" looking base. So, is it your thought is that I have the correct size stem hole; it was the stem that required the chamfering of the hold itself to accommodate a wider base? Sorry for being so rudimentary, but I have a hard time getting my mind around mechanical and dimensional concepts.

maddog34

personally, i'd lightly chamfer the hole in the rim, and use a tapered seal stem, a cone shaped seal stem, as you understand it.
the chamfer will allow the straight seal type you have to start into the rim's hole...
technically, the inner face of the rim's hole SHOULD have a tiny chamfer anyway.. this is often done to clean off any burrs from the machining process. I often do this after drilling Presta holes out to accommodate Schrader valve tubes/stems... Burrs can cause leaks. I use a drill bit that is larger than the hole, and spin it a few times by hand... a countersink or Center Drill bit are best for the task...
wear gloves or have calluses!

https://en.wikipedia.org/wiki/Chamfer

ArgoMan 

Thanks maddog! I got the "chamfer" concept, as I have a bit of a history in welding. I'll check the inner holes to see if they're has already been chamfered a bit and use the stems with the "cones" (if you will) in the future. I'm so disappointed, as I'll be running tires in an Oly this weekend that are designed to be a bit more puncture resistant, so as to better avoid puncture from all the goatheads we have in these parts. That's all fine, except that they're slower tires. Thanks again!

maddog34

Good luck on your Race... just pedal faster to make up for the heavier tires..

locally, we deal with Plum and Hawthorne trees, and English Blackberries. AKA: Briars.
the briars seem to reach out and grab flesh too...
the South Coast of Oregon has a invasive plant called "Gorse"... it grows near the Sand Dunes....NOT fun stuff.