Reserve Fillmore Valve Stem Review


Review by Drew Rohde

We have to admit, while we’ve been “Testing” the new Reserve Fillmore valves, writing a review on them didn’t seem to be too high on our priority list. There’s plenty of small, easily forgettable parts on all of our mountain bikes that, while incredibly important, don’t often get much thought. Seat post clamps, rim tape, and tubeless valve stems are a few items that can make or break a ride, but don’t get much mental space, or wallet space for that matter. We love to customize our bikes to add personal flair, improve comfort or performance, yet sometimes it’s the little things that make a big difference. With that said, let’s discuss what we think are the best tubeless valve stems on the market, the Reserve Fillmore valves.


Several months back we got an email from Santa Cruz Bicycles, owners of Reserve Wheels, and the bold EMBARGO title got our attention instantly. Expecting something fun and exciting I opened the email to find a top secret new…valve stem? I may have giggled a bit, wondering why a brand with such impressive products would be so secretive and excited about something so mundane. It wasn’t until I got the valve stems in my hand that I began to also see what was so cool about the Fillmore stems.

Reserve Fillmore Valve Stem Review

Unchanged since the late 1800’s, the Presta Valve has been the standard in high end bicycle valves for over a century. Reserve’s Fillmore valve stems are built from 7000-series aluminum and feature a stainless steel internal rod that controls the poppet that seals off the airway into the tire. There is no valve core and therefore will not clog or require removal to add sealant or set the bead of a tire. The self-clearing poppet can shed sealant build-ups and remains compatible with inserts like Cush Core. There may be some combination out there that will prove us and Reserve wrong, but Reserve feel confident that they’ve tested lots of pumps, wheel and insert combinations to ensure the Fillmore stems work for as many riders as possible.

Since the Reserve Fillmore valves don’t have an inner core, air and sealant can flow much easier, which is great for inflation and sealant top offs. Reserve claims a 3x gain in airflow, but we don’t have the equipment to validate that claim so we’ll have to take their word for it. There is no doubt that it is faster though.

There are some other noteworthy features of the Reserve Fillmore valves. First up they come with a lifetime warranty, which should put some at ease after looking at the $50 price tag, meaning they could be the last valves you ever need to purchase. Other neat features include the ability to directly inject sealant into the stem as well as Reserve’s Micro-Adjust, which is really just a fancy word for slightly unthreading then tapping the cap to air down.

Reserve Fillmore valves come in 50mm, 70mm or 90mm lengths to fit rim depths from 18 to 68mm, in black only for now with colored cap kits available separately for $10.

Reserve Fillmore Valve Stem Review


In all honesty, I didn’t foresee us publishing a review of the Reserve valves up on the site. Sure, they seemed neat at first look, but with a never-ending stream of products coming in to test, the queue is long. Valve stems are usually easy to forget when new tires, forks, and bikes keep showing up that’ll impact the reader’s trail experience more. It wasn’t until I was installing my third set of Fillmore valves on a test bike that I realized “I’m putting these stems on as many test bikes as I can for a reason. I should probably share that with our readers who are tired of clogged valves and hate breaking tire beads just to add sealant.” So, here we are.

Beyond establishing that the product does what it claims, and they do in fact kick ass, there’s not much else to evaluate. We’ve used several different types of sealants in several different wheels, both carbon and aluminum during our test period. The stems insert into the rim just like any other Presta valve and appear to be just as airtight. What’s different about the stems is the high flow passage that lets air enter and exit quickly, meaning that popping the bead of tubeless tires onto the rim no longer requires valve cores being pulled. They have also avoided any of the “sticky core” sensations that can make it tricky to air up a tire with a standard hand pump. Airing down may require some recalibration of your time-tested finger tap, so be sure to get out the gauge to see just how many PSIs you lose with each tap to ensure your trail-side pressure changes don’t leave you in dangerous territory but saving the small step of fully unthreading the cap prior to unthreading the stem was appreciated.

While our whole crew really likes the Reserve Fillmore stems overall, they’re not perfect and we’d like to see one improvement made. The cap can easily be lost and while you can still complete your ride without it, it is important to have the cap for protection and covering the hole that enters your rim. In fact, on one of our first rides out with a nameless Santa Cruz employee, we got a flat tire and lost the cap on the first run. We’d like to see some sort of solution, like tie-wire or something else to keep the cap connected to the stem.

Reserve Fillmore Valve Stem Review

The Wolf’s Last Word

Beyond the valve cap criticism, the Reserve Fillmore tubeless valve stems are a product I easily recommend, as it’s a product I am personally installing on any bike I plan to be riding for a long period of time. It’s one of those things that makes you say, “Why didn’t anyone think of that sooner!?” Now if only we could get them in a few more colors and for a few less pennies.

Price: Starting at $49.99

Disclosure: Our team selects all of the products we review and do so with honesty and objectivity in mind. Some of the products we receive come directly from Competitive Cyclist, who also value our readers and have offered them a 15% discount (exclusions apply) on their first purchase by using LOAMWOLF15. Through this program we may also receive a small commission at no cost to you. Thanks for your support, TLW.

We Dig

High airflow
Easy to add sealant
Setting tire beads without extra work
No clogs

We Don’t

Losing the cap
Color Options are Extra
Pricey, but justifiable


Want to win some free schwag? Leave a comment and vote up the most thoughtful comments and each month we’ll pick a winner. The person with the smartest and most helpful replies will earn some sweet new gear. Join the Pack and get the latest news and read the latest reviews on the top mountain and electric mountain bikes.