To Bend or to Break?
So, tubeless valve stems. They serve as the gatekeeper between a tubeless tire and the outside world, allowing air in and out- ideally when you want and not when you don't. Being someone who finds it hard to resist the urge to try new tires and casings, who sets up a lot of bikes, and who spends a lot of time on thorn- and glass-infested desert roads and trails I have spent a good deal of time with most of the tubeless valve stems on the market. Some are good, some are bad, mostly are solidly OK.
Over the past several years, it's become common to see traditional brass valve stems replaced by aluminum models. They're generally seen as a way to save a few grams, provide some perceived value to aftermarket wheelsets, and add a bit of color in the process. They almost all accept the same style of Presta valve core which is welcome given that the cores have the smallest holes in the system and are almost always the first part to be gummed up with sealant.
The problem is that they're a bit fragile. Not -for the most part- in the I'm taking reasonable care with lightweight components sense, but in the I'm frantically adding air mid-race and FAAAAAH! or I'm hanging my bike from a hook after a ride and WHERE IS ALL OF THAT AIR AND SEALANT COMING FROM? sense. You see, in order to fit through standard Presta rim holes (a good thing) and accept standard valve cores (another good thing) the walls get awfully thin near the top, with the distance between the deepest part of exterior threads coming really close to the deepest part of the interior threads. Throw some sharp edges into the mix and a not-terribly-forgiving material and you've got a part that will work fine... until it very much does not.
So, knee-deep in titanium, we set out to design a better, more durable tubeless valve stem. And, as the folks working in aluminum have found, there's not a lot of wiggle room between what will fit in peoples' rims and what the weird world of valve threads will allow. But seeing as the best design is born from difficult constraints I think we managed to pack some pretty good stuff into our Titanium Tubeless Valve Stems.
Let's start with the material. We knew that titanium would be stronger on paper, but our first samples (top image) were better than we'd dared hope. When mounted to a test rig, the titanium stem (right) was able to take about four times the force that it took to shear the aluminum stem. About four? Well, after 4x it kept bending- so much so that it would have needed cutting out if bent any further. That's also about where the brass cores failed, cracking where the valve stem cut into the softer metal. So the $2 consumable becomes the first point of failure- exactly what we want (and a good reminder to toss a valve core in with your spare hanger in the 'big day' bag).
As we know, Ti is more expensive than aluminum- not just to source as a raw material but also to machine. So we wanted to keep our valve stems in service as long as possible. Besides, who needs another non-serviceable, disposable product? That meant using a replaceable gasket (the rubber part that seals against the tire bed) and making those available alongside replacement valve cores. As of launch, we sell Refresh Kits with four gaskets, four valve cores, and a core removal tool (enough for two bikes) for under $10. Some of these parts might look familiar- if you have another brand of valve stem with a 5.9mm base they probably came from the same mold and are 100% compatible if you're in need. (We won't tell.)
There's also our Bead Shed Technology. That's marketing-speak for the patent-pending geometry at the head of the valve stem that helps beads find home during installation. Ideally, you'll never notice it working- it'll just help to keep the bead from getting caught up on the valve stem and making a horrible sealant-stained mess of your clothing and workshop.
Also, because we aren't over-molding the gasket, our thru hole (left) is 86% larger than a standard valve stems'. The valve core is still the chokepoint limiting air flow, but a large, clean bore keeps sealant from being trapped on the inside wall between the gasket and valve core and, if you like to seat tires with an air compressor and the valve core removed, will make a big difference to bead-seating air flow.
But how do they look? They look great! Ti doesn't lend itself to anodizing in the way that aluminum does so we stuck with some more repeatable colors (natural, gold, and charcoal) for the first batch. If you're so inclined, we added a hit of color on the nuts, with red and blue anodizing that looks awesome next to red or blue spoke nipples. We left off the fancy machined dust caps because they add cost, never really thread on nicely, and are inevitably the first thing lost. Branding, as you might expect, is minimal, with our Traben hex logo etched on the nut flats.
The O-ring is there to prevent rattling and serve as a reminder not to go crazy on carbon or thin-walled aluminum rims. If you're having to crank on the valve nut to get a seal, it's probably time for a new gasket (cough, cough).
Find your own Titanium Tubeless Valve Stems here.