Stans Exo-Core Valve Stems: Review

 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.

The Stan's Exo-Core Valve Stems are a unique take on a tubeless valve stem designed to solve a couple of issues seen with traditional tubeless valve stems of the Presta variety. Namely low-air flow and clogging due to sealant accumulation along the valve seat.

Stan's solution to these issues results in an oddly chunky looking valve stem made from anodized aluminum.  And, at $55.00 a pair, these are some premium priced stems. A cursory look at what the market is for aluminum tubeless valve stems shows this to be true.

Due to these facts, I am expecting some notable differences in use with these stems. So, let's take a closer look at what is going on with the Stan's Exo-Core stems.

Here is a bullet point features  list from this product's webpage: 

• Compatible with rim inserts
• High-flow for air and sealant
• Anti-clog design resists clogs
• Tool-free core removal
• Customize with Valve Color Kit

The Exo-Core stem in the "closed" position.

After taking off the push-on/pull-off aluminum valve cap you can see the above view of the stem's end. It does not have the traditional nut/threaded rod arrangement you might be familiar with on a typical Presta valve. Instead, the entire exterior of the valve on this end is the "nut" and you have to unthread this to introduce air. This is quite unlike a traditional Presta valve. The grooved base can be seen in the image above and this is what you would grasp to open up the valve. By the way, a traditionally designed cap made from plastic or aluminum will thread on to this valve's end, in case you want to ditch the chunky push-on cap Stan's uses with this stem.

 Here I have unthreaded the "nut" to the point which one could introduce air through the valve. The threading of these pieces feels as though there is a thread locker paste on them, but there is none. Why extra resistance is felt when unthreading this "nut" is something of a mystery to me at this point. But it does not unscrew without effort.

 Here you see what happens when you unthread the "nut" all the way. This removes the valve core and reveals the larger opening than you'd normally have when removing a typical valve core. This is why Stan's claims of anti-clogging and better air flow are made., You can see it in the design. We will see how it works when I set up some tires with this design soon.By the way, the valve seat is within the "nut" portion you can unthread from the main stem shaft. How one would replace this bit, if necessary, is unknown at this point. Perhaps Stan's would sell replacements?

By the way, the stems weigh about 7 grams each with their caps. So, while these look heavy, they are not bad in reality. Also, these valves have a Lifetime Warranty from Stan's.

Impressions: Judging by the looks of the design and the open areas around the core shaft near the top, I think it would be best to run a cap on this valve of some sort. Otherwise you may run the risk of debris, mud, or water getting down there and fouling things up. I'm not a fan of Stan's caps, and I'd feel a bit better about some threaded option, so I will likely use different caps on these than Stan's sent.

The other thing which I had thought of right away is how this design would be easier to use in inclement weather while having to have gloves on. That base with the grooved edge makes for a much easier to grab object to open up the valve with than does the traditional tiny brass nut on a Presta valve. 

Stay tuned for updates on this and the other Stan's products soon.