Saturday, November 06, 2021

Probably Not For Me

The Fillmore valve. (Image courtesy of
 The interweb-o-sphere was a buzzin' last Thursday concerning a new tubeless valve stem called the "Fillmore". (Clever marketing right there!) I saw these things and began to think about what issues these new valves were solving and if I might need this answer to a question I was unaware of until now. 

First of all, while this is not a Presta Valve, it is highly derivative of that design. In essence, it is just a rearranging of a Presta Valve to put the sealing end at the base of the valve so it can be larger and therefore "flow more air" when one tries to seat a tubeless tire. 

So, I looked at this thing and researched the site with a particular eye toward the FAQ section. Here's my take- and let it be known- this is only my take. Others may have a completely different view on this deal.

First off, the shaft of the Fillmore valve and a typical tubeless Presta Valve are basically the same. They have to be to fit the standard rim holes we have. So, the entire shaft of the Fillmore is basically exactly the same as an ordinary Presta Valve. Where it differs is at the base, and it has a bigger seat for the valve. You can think of this in Internal Combustion Engine terms- A bigger valve lets in more air/fuel mixture than a smaller one. (If the intake pressure and cam timing are the same in both examples- that is)

Okay. Gotcha. How about that "O" ring valve seal? What can I do when that gets deformed and breaks down due to exposure to chemicals in the sealant? Well, bad news here. From the FAQ: "No, Fillmore valves are not rebuildable." Okay, so what about checking for sealant levels where I used to be able to remove a Presta Valve core? Well, since a Fillmore Valve does not have a removable core, you cannot do this if you use them. What about deeper rims as we see some in gravel wheel sets? Too bad- Fillmore valves only fit 18mm - 25mm rim depths. What about pumps? Up front, the FAQ says, "No, no special pump is needed", and then further down in the FAQ it says, "Unfortunately, there are pumps and gauges that do not function well with Fillmore valves.


I have noted that there are higher flow valve stems for tubeless applications available from CushCore and Muc-Off which do not have the limitations of the Fillmore system. Also, these Fillmore valves cost fifty bucks. 


I have determined that no- these are not for me. 


teamdarb said...

Sheesh, I laughed as soon as I saw this posted elsewhere. It is just a Presta valve insert upside down. Same same. It is like changing your gearing from 40/24 to 24/40. They placed the taper at the bottom of the tube. said...

My personal opinion is these are more marketed towards mountain bikers. I particularly think they'd work well on a fat bike or plus size wheelset. I also laugh at people scoffing at the $50 price. I did order a set for testing and Considering the cost of the wheels I plan on putting these on are north of $1,200 I think $50 for two valves is not the worst investment in the world. I want to compare them to a set of Lindarets vavles that I have. I do think the idea is worth checking out and as others have pointed out on other websites....highly doubt these o-rings are proprietary. You can get o-rings many places for pennies each.

Guitar Ted said...

@onoffrhodes - Glad to know they appeal to you. I'm still not convinced they are for me, and I own a tubeless wheeled fat bike with very expensive wheels as well.

But again- you do you. I never said they weren't for anyone.

The FAQ said the valves were not serviceable. I'm not saying the "O" ring is proprietary.

Again- my question would be- What are questions are these valves are answering? Do they make field servicing MTB wheels easier? I could see that, perhaps. But beyond this, I am having difficulty seeing where these valves have more advantages over the typical tubeless Presta valve.

I'm willing to change my mind, but until I read or see some compelling reasons to switch, I am sticking with "Probably not for me."