Stans Exo-Core Valve Stems: Update 1

 NOTE: Stan's sent the Biobased Bike Care Products, Stan's Exo-Core valve stems, and Stans DART tool for review to Guitar Ted Productions at no charge. GTP is not being paid, nor bribed for this post and all opinions are Guitar Ted's.

In my last update on this review I told you how this unusual valve stem works and showed a pictorial view of the parts of this valve stem. If you missed the introduction, you can go back and review it HERE. 

In this post I will detail the installation of the valves and how they worked when pumping up two different tires tubeless. I also did a test ride and I plan on using this wheel set off and on throughout the riding season. I plan on doing a final conclusive review later on, but at the end of this post I will give my basic opinion on these valve stems so far. I do not expect to have any changes after riding these for a season, but just in case....

Installation: Since these valves are constructed so differently from anything else I've used, installation was a bit new to me. You may recall from the previous post on these valve stems that you can uncrew the upper portion of the valve to "open" the system to allow for air to be introduced to the tire. Well, as you might also recall, you can keep unscrewing this upper part and remove it, which takes the valve core out, leaving a larger bore stem for higher airflow.

I mention this as this upper portion of the Exo Core must be removed to install the valve stem through the rim valve stem hole. You can see this in my image below.

You will also notice the inner seat of the valve stem is a saddle shape. I suppose the inner rim well will dictate how to orient this elliptical shaped seat in a rim, but in this case you can see it was best oriented in the way you see it above.

The next step is obvious. The valve stem nut must be threaded on to secure the stem to the rim. This was easy, but there are two comments I have concerning the nut. First: It is, as stated in the previous post, a bit stiff to turn on its mating threads on the stem. Perhaps this was intentional. A sort of way to insure the nut does not rotate/vibrate loose, I would guess.

Secondly, and this is not aimed at just Stan's, as many company's stem nuts have this issue, the nut is too small a diameter to turn easily or get a grip on well enough to really get it snugged up firmly. But then again, this also may have been designed in so a person couldn't reef that nut on too tightly. At any rate, those are small negatives I have and are not really that big of a deal.

As you can also see, the inner portion of the valve does not stand too proud of the rim sides, so it is unlikely you might strike it while riding low pressure and hitting something pretty squarely. Of course, these stems are compatible with rim inserts should that be a concern.

Now at this point I could have mounted the tire, introduced sealant, and pumped up the tire with the core removed. But that would be too easy! No, I decided to put sealant in, put the core/top part of the stem on, and see if I could leverage just the bigger bore and different nozzle of the valve stem's end to get the tires to mount.

I used my SILCA Terra pump, which is a higher volume floor pump, and I have to say, this was the easiest tubeless tire installation I've ever done. It was honestly no different than pumping up a butyl tube. Really. I was impressed!

Note: The core's end does not touch you pump's head because it is shielded.

Another interesting thing I noted about the Exo Core stem is when it is opened up, the valve core is not exposed. This means that when you attach a pump head it does not depress the core plunger and release any air, Same goes for when you remove the pump head. So, in theory, you should be able to get more accurate air pressure settings.

So, using these valve stems would seem to be an advantage in a couple of ways. First, it seems to be a good, high-air flow stem, making stubborn tubeless set up combinations a little less stubborn, or, as in my case, really easy. Secondly, with a non-exposed valve core, you don't accidentally release air when you don't want to.

 I used two different tires, as previously stated. One is a notoriously stiff, and generally harder to set up Teravail Sparwood. The other was a big volume Teravail 29" X 2.3" Ehline. I mounted both on WTB Proterra wheels with a 23mm internal width.

Final Words - For Now: I like these valve stems. They are different, but in a way which makes them better than a traditional valve stem. My hope going forward is that they will not clog up easily with sealant. Otherwise I see no reason these stems would fail me going forward. But as they say, "You never know", so I will keep using them off and on throughout the riding season. If anything pops up which would be noteworthy, I'll report on it, but otherwise I feel these stems, while insanely expensive, do have some merits which are benefits other valve stems don't have.

I am annoyed by the stiffness of threading things on and off with these, but how often am I really going to be taking everything apart? Hopefully only if I want to disassemble the stems, not because I have to do this. Then the stiff threads are no big deal. The valve caps are a bit dorky, but maybe this is just something which offends my eyes and you may not mind them.

It is hard to knock these stems, at least at this point, besides the expense. You can get by for less, that is for sure, and in these times, I feel many won't want to spend the fifty-five bucks for a pair of these stems. I understand this. I can also totally see why these stems cost the amount they do because they are so different. There are no other stems made in this manner, although, I will say I think this design is superior to traditional tubeless valve stems. From this standpoint, they are worth the asking price.

Check in later this year for a final look at these stems, unless something happens which would warrant an update.