Fillfast Valves

Tru-Tension Fillfast valves, another Presta rival enters the fray!

Fillfast valves from Tru-Tension are looking to make tubeless life that bit easier. This new system from the UK manufacturer promises greater and faster air-flow compared to Presta. It also promises to be ‘no clog’, important when dealing with tubeless sealant. So let’s take a look at these new valves.

Last year we wrote about various brands looking to oust the venerable Presta valve from its position as the valve system for tubeless. Tru-Tension’s Fillfast valves are a two-part system, in that you can buy just the top part of the valve; that’s where all the action is. This means that if you already have your valves set up and ready to roll, you can just buy the valve head and screw it on. This will save you around £10, so it’s worth considering to save time and money!

How do the Fillfast valves work?

As to how the Fillfast valves actually work, well that’s not clear from their website, but we do have some samples coming. Looking at the images on the site, it looks like there’s a hollow stem with a nut on top. I assume the nut will pull the stem up or down, closing off the air-flow. However, as I said that’s just my assumption, I’ll let you know when I get my grubby little hands on them.

If you’re wondering why there are suddenly so many Presta alternatives around, it’s down to tubeless. Running a tubeless set-up brings with it some issues that Presta valves struggle with. First are Presta’s narrow internal dimensions, which make initial set-up difficult. You need a good volume of air rushing through the valve to pop the tyre on to the rim. While some tyre/rim combinations will allow you to seat your tyres with just a track pump, others require a bit more ‘oomph’!

So taking the Presta valve out and replacing it, but still keeping the stem is what’s needed. Tru-Tension came up with their Fillfast design which they say allows 3.75 times more air through, compared to a Presta valve. And it fits onto the existing stem. All of which should make getting your tyre onto the rim much easier.

Sealant clogging

Another issue that occurs with Presta valves is sealant clogging. Tubeless set-ups use sealant to plug holes and keep you riding. The particles in the sealant rush into any holes and block them, allowing you to keep riding. The only problem is that the inside of a Presta valve is so narrow that it’s perfect for sealant. Over time you’ll find your Presta valves become more and more clogged, until you have to replace them.

Tru-Tension say that “FILLFAST ensures blockage-free performance, preventing sealant build-up that can hinder inflation.” So, if the Fillfast valve’s internals are wide enough to allow 3.75 more air to pass through, presumably this means that they’re too wide for sealant to clog. Or, perhaps there’s some kind of coating or design that stops this? Again, until I get my samples, I can only guess. So until then check out the Tru-Tension Fillfast Valves on their website and look out for a preview on CycleTechReview soon.