Foss Tubes, stem turning?

I’ve got a Foss tube on my 36, it’s one of the clear ones from UDC. I have one of those decorative caps on it, metal on the inside. Last time I noticed it was kind of hard to unscrew, didn’t think much of it. Today I was going to check my tire pressure and it seemed really hard to unscrew, then I noticed the whole valve stem was turning. What the heck?

Wondering if there is some kind of corrosion going on between the two different metals (valve stem is aluminum I think, valve cap?? looks brass maybe).

Also wondering if my tube is all right?

This may not answer your question, but one time when I was checking the pressure on my 36" Foss tube the air pump valve was difficult to remove, as it sometimes is. With a little extra tug, the entire valve tube came out of the tube with the air pump fitting. That was the end of that tube. Since that was the second in a row of Foss air valve tube failures, I switched to a Schwalbe 29" rubber tube and haven’t looked back. (The 29r is about the same weight, or less, than the Foss.) No problems since then.

Thanks for the info LanceB.

I’m going on a ride tomorrow, it’ll be out in the boonies. Maybe I should bring a 29er tube with me.

If it’s only been used on a 29er should I pump it up tonight to stretch it out? Is it necessary, or is it just easier with one thats been stretched out?

My 29er has a loose valve stem. Its not between cap and stem and is i believe a common issue with these tubes. If it isn’t too severe it shouldn’t be leaking air.

When i inflate foss tubes i make sure to hold the valve stem whenever i do anything that turns it.

If its just started, i would bring a spare tube just in case.

as Foss tubes are weak at joints, I always hold the stem firmly fixed anyway, as I do not want to twist it at all.

But about your problem; it be the blue part is a seperate thin alu tube?

I’ve read some fairly extensive procedures that some people do before they mount a 29r tube on their 36" wheel, but I just took it out of the box, put it on and pumped it up. So far, so good!

Like Leo, I also get the impression that the valve stem is aluminum. Possibly what makes it more problematic is its smaller diameter, which may make the joint with the tube inherently weaker. I also recommend holding the stem in place when putting pump on and off. I don’t think I do this as much with regular tubes, but it just seems more necessary with the Foss.

No relation, BTW. Still curious as to how the Taiwan-based company chose that name.

Allright, thanks for the info everybody. 22 miles today and it holds air so I’m not going to worry about it. I’ll be careful with the stem though.


I just replaced a wheel, and took a close look at the valve. the blue tube is the same as the where the thread sits. But the bottom is mounted on some kind of plastic.

Thinking of it; except ti I doubt there any other metals that can be anodized. But getting ti resulting always in such a solid color would be extremely impressive. So it must be alu (or alloy).

You’re not talking about french valves, eh? Cause I have a regular schradar.
Same diameter, but no covering rubber, that might look like the valve is thicker.
But the “rubber” part that joins with the innertube is in deed pretty small compare to regular valves on butyl.

For the freaks; I’m also retailer, and so I can purchase at distributors. So now I have 20" 1.35 - 1.75 (in stead of 1.95) in stock.

Some other innertube…
Not sure about the real history, but IMHO long before Foss there was the Eclipse from Switzerland. Looks very alike, but more transparent and shiny. But it took the factory forever before they could supply.
I’m curious about that one! But have no wheels in any of those sizes (yet, but planning).
For sale over here, and not a cheap product…

It should not spin, you probably have a broken valve, this happened to me once right before a ride.

The valve is the weak link on that tube. The base of the valve is drilled on the sides to allow air flow into the tube, as a result the remaining four"tabs" are not that strong and can break.

Hold the valve when pumping or adjusting the valve cap, don’t run a large “fun” cap, and make sure the tube isn’t slipping on the rim.

What’s wrong with that i.c.w. a Foss?
I actually always did so; one that measures the pressure and warns at a fixed underlimit.

When you tighten a large valve cap, you have more leverage, which would make it easier to spin the entire valve.

I don’t know how many threads we have to have about Foss tube problems before people stop using them. I guess when you spend $20 on a tube you feel compelled to be content?

Actually it’s $38 tube!

AND it’s rebranded as a Nimbus tube. (Foss tube in a Nimbus box)

Maybe they should stop selling uh… er… tubes that suck?

Yes, I do prefer Foss tubes. But no, I’m not a huge fan either.
Still I’d like to make a few remarks here:

Aha, so the large valve cap is not any cause.
Not holding the stem fixed is.

Except problems of people that don’t read manuals, and this specific one, what “many threads” about problems are you talking about?

Not sure if I understand it. Does that make them better or worse?
Secondly; all the spare ones I have here are in a blue box that says “Foss”.

Yes; valid point. And including all regular ones!
Cause they sometimes suffer the exact same failures.
Oh, and I think at one point every innertube sucked.

When I buy something, I like to know what I’m buying. When an item is sold as one brand, then I open the box and find it is a difference brand I don’t like it, I feel like I’ve been swindled a bit.

Yeah, they should add the use of a large valve cap to their BOOK of directions!

It’s an inner tube! Why on earth does it need 4 pages of instructions?

Covering their butts for a finicky piece of gear I presume.

If they beefed up the valve, it seems like the the tube overall would be fine, at least I never had a tube failure. If I get another failure, then I’ll just use it for a spare in case I get a tubeless failure.

I am using one now because it is lighter than the rubber tube and I may not run this one tubeless; though I probably will in time :wink:

First off, why in the hell does an inner tube need a manual? I mean really, why should it matter where the seam in the tube is placed?

Second, maybe I exaggerated a bit on how many threads we’ve seen on the subject, but there was one recently dedicated to Foss tubes, as well as posts here and there where it’s mentioned that a Foss tube leaks air, burst, etc.

I’ve also ridden with someone who claims their Foss tube will hold air at a certain pressure, but won’t at other pressures. That seems rediculous. I’ve also had first hand experience with a Foss tube bursting spontaneously.

Tubes are simple, easy things. You put it in your tire, blow it up, and ride your bike/unicycle. If you get a flat, you buy a patch kit from just about ANYWHERE on the planet, glue it on, and be riding in 5 minutes. You don’t need ‘special’ patches, and you don’t need to worry about how you install the tube. If I forget to hold the valve stem while I’m screwing on the cap, I don’t have to worry about ruining a $40 tube.

I guess I just find it amazing that someone found a way to over complicate something as simple as a tube, and markup the price by 700%. And people buy into them.

If you want lightweight, go tubeless, or run a smaller normal tube.

But who am I to judge? If someone wants to use Foss tubes, more power to ya. But when I see you stranded on the trail, I probably won’t have patches that work ;).

If I look at this page, it clearly tells Foss. Even if it didn’t; did you truly expected Nimbus to have an innertube factory?
You might have bought it at UDC, but even that pages even shows a zoomed-pic if the valve, plus even refers to the manual.
I do suspect Foss made special sizes for Nimbus, so in stead of complaining about a box, I (speaking for myself) rather be happy the size I need is available trough them.

I don’t know US consumer laws, but in the EU the seller is responsible for factory failure, which I think is hard to deny your valve issue is.

Foss tubes are decadent, have weaker joints, are more porous, and certainly require extra attention.
If a reading a manual (and getting knowledge) bothers someone, then prepare to be disappointed.
Not something unique to Foss tubes. Or let’s counter-ask: why would they have written a manual?

Try this: take a normal innertube, inflate it with a very low pressure just enough that your rim doesn’t hit the floor. Make sure the valve sits straight. Ride for a little while. Check if the valve is still straight. Seems like that same force is killing the seam faster if it tears it apart, compare to when it pushes it together.

Sounds more likely a valve pin/ring issue, than a magic porosity thing.

I use Foss before it became popular in unicycling. It was because I wanted latex, as long ago I was used to when using Vittoria CX tubes (like Eddy Merckx’ mechanic man stocks in his wine-cellar). That rides completely different compare to clinchers with butyl. For that reason there is still professional riders (anno 2014) who use those in Paris-Roubaix and even this latest edition of the Tour de France. In my desired size I found no better alternative yet, and still wish for latex.

Foss tubes I do trust enough to even do pair acrobatics on. But patches; I never use. It makes the innertube unequal, I’ll always replace the whole innertube.

You are correct sir, I should have checked all around the earth to find a better description of the product I bought in the U.S.A.

I think what it all boils down to is it’s just an inner tube, it doesn’t need to be so complicated. Why would I check the directions/instruction booklet when all I’m buying is a tube? But me not paying attention got the best of me. It won’t happen again.

Geez @Leo you own stock in FOSS or something? You seem to be taking this very personal… I certainly didn’t intend to offend you. I’m just not satisfied with their offering…

You’re the first I notice with an reasonable Foss complaint, so no; you didn’t offend me.

And I do think pricing is also an acceptable complaint. However, distributors tell me it’s an undesired product for cycleshops: so many customers ask so many questions, costing them more time than the product’s margin would compensate (in the case that the customer would become a consumer).

No, I don’t have any financial or other involvement in neither Foss nor Nimbus.
If I had I’d only allow sales to customers who pass a little exam.

I remember how the company Pariba got in trouble when making latex innertubes early '90’s. They would melt near the valve if you pump them up too quick, especially i.c.w. compressors. They could preach all they want, but the very same “it’s just an inner tube / it doesn’t need to be so complicated” kind of argumenting there, and when the customer ignores factory instructions (because they think they know it better) then suddenly the product is bad.
There was nothing wrong with the product, only with the users.
The result: the company went bust, and got acquired by Vredesteijn, who recently suddenly started to reproduce them (but do not wish to make 20").

Michelin is also having everything to make 20" latex innertubes. They confirmed even the mold is at the right factory. But the scarcity on latex juice made them decide to only target bicycle racing and mountainbiking, not BMX and certainly not unicycling.
They would have all the same disadvantages, be even more porous, plus have a slow-pump requirement, and if you don’t divide equally you will be punished directly.
But the thin super-elastic material would provide more comfort at higher pressure, which for a unicycle would have double effect.
I’d much rather would invest there.