While many mountain bike frame and component standards have undergone numerous changes over the past couple of decades (and not always for the better), the humble presta valve has largely remained the same since its invention. That was totally fine up until we started putting sticky tubeless sealant inside our tyres, which as many of you will know, has a habit of clogging up the little nooks and crannies inside the valve core. Even if they are nice and clean, presta valves don’t always allow you to pump in a large volume of air, and that can lead to issues when trying to inflate and seat the beads of a tubeless tyre.
To tackle these issues, Santa Cruz’s wheel brand Reserve recently introduced its nifty Fillmore tubeless valves. The unique poppet valve design allows for a much higher flow of air, easing inflation while also reducing the chance of sealant clogging up the innards. We’ve found the Fillmore valves to work really well, though at $65 AUD for a pair they’re not exactly cheap.
Aiming to achieve a similar goal, the brand new Funn Fastair tubeless valves recently arrived at Flow HQ for us to check out. They also bring a unique take on the traditional presta valve, though at $54.95 AUD for a pair they’re a marginally cheaper alternative.
Funn Fastair Tubeless Valves
- Weight: 14g (confirmed)
- RRP: $54.95 AUD
The Funn Fastair tubeless valves are designed to replace any standard presta tubeless valve, and they’re said to be compatible with most mountain bike and gravel wheelsets. They currently only come in a 50mm length, so those with deep section aero gravel rims will need to look elsewhere.
Featuring a unique construction with three main components, the Fastair valves utilise a CNC machined alloy outer tube, a hollow stainless steel inner tube and a threaded valve cap. They’re fully rebuildable, only requiring you to remove a plastic circlip to pull them apart for cleaning.
Big air flow
In terms of function, the Funn Fastair valves are quite similar to the Reserve Fillmore design. The stainless steel inner tube forms a simple poppet valve, with a small rubber gasket at the base allowing it to form an airtight seal when pressurised.
As with the Fillmore design, the Fastair valves allow for a higher volume of air to pass through during inflation. Funn says its around three times the air volume of a traditional presta valve, and in practice it feels like that’s close to the truth. We’ve found it a doddle to quickly inflate and seat the beads of a tubeless tyre, and because the valve is less likely to clog up with sealant, you can expect that ease of inflation to be maintained over a longer period of time.
Compatible with tubeless inserts
Compared to the Fillmore design, the base of the Funn Fastair valve is quite a bit chunkier. It’s also slotted, which avoids the chance of a thick tubeless insert suffocating the valve. The downside is that the extra height of the valve base means it pushes slightly into the CushCore insert we’re running in our rear tyre, and that will be the case for any insert that’s designed to sit snugly in the rim channel.
Because the edges of the machined slots are fairly sharp, it’s already cutting into the insert. This doesn’t really affect performance, but we’re curious to see if it causes any notable damage over time. Alternatively you could cut out a deeper hollow in the insert to make room for the base of the valve.
In terms of longer term use, we like that the Fastair valves can be easily disassembled to clean out any residue sealant – something that is quite tricky to do with conventional presta valves. Also neat is the integrated valve cap, which is drilled to allow air to pass through it when making pressure adjustments. Simply loosen the cap a couple of turns, press down on it, and you’re able to bleed a small amount of air from the tyre.
You can also fully unthread the Fastair valve caps and push down on the stainless steel inner tube to let out a bigger volume of air. Make sure you don’t lose the valve caps though, as they are specific to the Fastair design.