Coreless carbon valve stem says sayonara to breaks and clogs

Presta valves are one of those things that a lot of serious cyclists use, but perhaps secretly hate. Well, those folks might have a much more loving relationship with the Aether valve stem, which does away with a traditional Presta valve's problematic core.

So first of all, why do most "fancy" bikes even have Presta valves in the first place?

Among other things, they're better than Shrader valves at maintaining high air pressure, they're lighter, and they're narrower. And because they're narrower, the holes that are drilled in the rims for them are smaller, and thus less likely to compromise the integrity of narrow road bike rims. Additionally, their cores can (usually) be removed, allowing sealant to be injected through them into tubeless tires.

Those cores, however, are annoyingly fragile – they frequently get bent or even snapped right off, plus they can can become clogged with sealant. That is where the Aether valve comes in. It's manufactured by UK firm absoluteBLACK, which also makes a graphene-based chain lube.

The carbon fiber composite device replaces the core with a rubber plunger mechanism that sits at the bottom of the stem inside the rim cavity. When the tire is being inflated, the air pressure pushes the plunger out of the way, allowing air to flow through into the tire. Once the pumping stops, the air pressure within the tire presses the plunger back up into a sealed position.

By absoluteBLACK's own admission, this setup is similar to bottom-sealing valves such as Fillmore and Peaty's, which are in turn based on a concept dating all the way back to 1915. The Aether valve is reportedly much simpler in design, however – it has just two primary functional components, the stem and the rod-plunger assembly – so it's said to be significantly less likely to clog.

At a claimed weight of just 2.6 to 3.1 grams, it's also lighter than other alternatives. And, because there's no core restricting the air flow, users should actually be able to seat tubeless tires via a regular floor pump. The simplicity of its design does have one tradeoff, however – it is not serviceable, so the whole thing has to be replaced once it stops working.

The Aether valve stem is designed for road, gravel and mountain bikes, and is available in sets of two for US$29.95. Presta-frustrated cyclists might also want to check out the CoreCap and the Clik Valve.

Source: absoluteBLACK