You asked for it: Latex tubes with aluminum valve stems

Triathlon Forum
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Turns out, it was a much harder problem to solve than it might appear at first, but today our latex inner tubes with aluminum valves are officially on sale and available worldwide. These are produced by Vittoria using SILCA made valves and cores, these save 10 grams per tube over our previous tubes which utilized Vittoria’s brass alloy valves and core. Vittoria has also done some magic in their formulating and these seem to weep air at about 1/3-1/4 the rate of previous latex tubes, which is a nice bonus!

You asked, we’ve worked hard(er than we thought) to make it happen. Thanks for all your support.

Happy to answer any questions you may have.

Josh

https://silca.cc/products/latex-inner-tube

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How long is the valve on the tube only option?

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Nice pricepoint and includes the stem fairing. How many watts does the fairing save again (or tenths of a watt)? All kidding aside thanks for all your contributions here Josh! If they leak less than regular latex that’ll be huge.

4

What are you thoughts on making latex tubes with valves long enough (80mm) to fit a HED jet 6 or Zipp 404 without a valve extension? They’re available in butyl, but I don’t think anyone does this with latex. Cost prohibitive? To hard to make? Not enough potential buyers?

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Is the valve core removable?

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The tube only has a 42mm valve, which is the perfect length for Zipp, Corima and Lightweight disc wheels, all of which have small access holes making 36mm too short for most pumps to grab onto and 50mm too tall for pump heads to fit in the hole.

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This tube has been sized to fit tires measuring 24-30mm, which will equate to 23-28mm tires used on modern wider rims. Valve stem length is 42mm and will work in all modern disc wheels.

8

Turns out, it was a much harder problem to solve than it might appear at first, but today our latex inner tubes with aluminum valves are officially on sale and available worldwide. These are produced by Vittoria using SILCA made valves and cores, these save 10 grams per tube over our previous tubes which utilized Vittoria’s brass alloy valves and core. Vittoria has also done some magic in their formulating and these seem to weep air at about 1/3-1/4 the rate of previous latex tubes, which is a nice bonus!

You asked, we’ve worked hard(er than we thought) to make it happen. Thanks for all your support.

Happy to answer any questions you may have.

Josh

https://silca.cc/products/latex-inner-tube

Josh, what was the request or benefit for switching to an aluminum valve stem?

If the new aluminum stem was threaded on the outside it would definitely offer some advantages over the Vittoria brass valve stem - such as better pump head gasket grip and the ability to stabilize the valve stem in foam core disk cutouts.

The less permeable latex formula sounds like a big improvement!

9

What are you thoughts on making latex tubes with valves long enough (80mm) to fit a HED jet 6 or Zipp 404 without a valve extension? They’re available in butyl, but I don’t think anyone does this with latex. Cost prohibitive? To hard to make? Not enough potential buyers?
Or a FLO 60. I think you’d find a market for 80mm latex.

10

Excuse my ignorance… I didnt know this was a problem. What issue does this change address? I searched for prior threads, but I didn’t find anything directly on point with this.

Trying to understand if this is a:

  1. Dissimilar metals problem (stem to rim or stem to extender)
  2. Total weight problem
  3. Wheel balance problem
  4. Brass /latex compatibility problem.
  5. Something I haven’t thought of…

Not being flippant… I’ve just never looked at my tubes and thought, “gee, I sure wish those werent brass, were lighter, or something.”

Slower leak down does seem like a nice perk, regardless.

I did see some evidence of what might be galvanic corrosion in the extender I removed while changing a flat last night.

11

Oh no… You can’t reformulate latex to leak less air without increasing rolling resistance. It’s now time for totally flawed amateur testing, endless “white papers”, and general panic around the Slowtwitchery Cauldron ™.

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el gato - valve cores are removable and are the ultra-premium SILCA ones which produced using roll-formed threads and fully machined critical features

J7 - The valve shields are only included with tubes sold with extensions. The shields save 0.2-0.5 watts of combined translational and rotational drag and also eliminate rattling and seal the valve hole

pun_times - there are 2 issues with this. One, the minimum quantities per valve stem length are quite high as the valve stems are applied/bonded by machine which has long/expensive setup times and often times tooling related to each length. So if we have to buy say 10,000 per size to justify the machine setup time, and we wanted to offer 3 sizes… there is no way we can afford to build and hold all that inventory, not to mention that prices would have to go up across the board to offset inventory holding costs, etc…

Second, the main reason that valves and extenders can be such a hassle is that they are generally made in the cheapest way possible, by extruding a tube and doing some minimal machining on it… this allows affordable 90 and 110mm valves to be made, but they have poor durability, have been known to rupture at high pressures over time, and the seam in the tube from the extrusion process can sometimes leave a slight flaw inside the tube which keeps the valve or extender from sealing properly…the flexibility of the tube wall also affects the machining quality and size control, I could go on about this…

We machine our valves and extensions from bar stock, which solves all of these issues but puts our maximum length of extension at about 70mm due to the depth of drilling the small internal hole, but it also guarantees a perfect match between sealing surfaces. Since the surfaces perfectly match (AND we use a special domed compression seal) our extenders and tube seal perfectly every time… no tape or any of that necessary, they just work…

So when you have valve extenders that just work, then it now also makes sense for the end user (or bike shop) to not have to carry as much about their inventory either… so you can have 2 tubes and some extenders at home and be able to service numerous depths of wheel…etc.

Long story short, we are confident that if you use our system, you’ll never give valve extenders another thought, and in that world, a single tube gives you the most flexibility at the point of use.

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Tom_Hampton - the ask for aluminum valve stems are purely about weight as all prior latex tubes have used brass stems.

In this case the stem is 10 grams lighter which isn’t a big deal for everybody, but then also offsets any counterbalance you might require so the savings can be greater, hassle reduced, etc.

Either way, the price is the same, so from our perspective it’s a pretty big win on all fronts.

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Thanks. I think Ill be pretty happy when I’m worried about drag effects that are two orders of magnitude down form what I’m worried about now.

15

those look like vittorias. i assume they’re vittoria clones, just with the aluminum valve stem?

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I know it was hidden in his post and all, but…

“These are produced by Vittoria using SILCA made valves and cores, these save 10 grams per tube over our previous tubes which utilized Vittoria’s brass alloy valves and core. Vittoria has also done some magic in their formulating and these seem to weep air at about 1/3-1/4 the rate of previous latex tubes, which is a nice bonus!”

17

I know it was hidden in his post and all, but…

“These are produced by Vittoria using SILCA made valves and cores, these save 10 grams per tube over our previous tubes which utilized Vittoria’s brass alloy valves and core. Vittoria has also done some magic in their formulating and these seem to weep air at about 1/3-1/4 the rate of previous latex tubes, which is a nice bonus!”

ah. okay. i didn’t read closely enough.

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el gato - valve cores are removable and are the ultra-premium SILCA ones which produced using roll-formed threads and fully machined critical features

Thanks Josh - these look great! I should have asked this earlier, but as a corollary to the previous question, I’m assuming that the valve extenders are the type where you can relocate the valve core to the end of the extender?

Edit - sorry, looking at the detailed photos on the website, it does appear that they are. Nice! That was my one complaint with the Michelin tubes.

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Second, the main reason that valves and extenders can be such a hassle is that they are generally made in the cheapest way possible, by extruding a tube and doing some minimal machining on it… this allows affordable 90 and 110mm valves to be made, but they have poor durability, have been known to rupture at high pressures over time, and the seam in the tube from the extrusion process can sometimes leave a slight flaw inside the tube which keeps the valve or extender from sealing properly…the flexibility of the tube wall also affects the machining quality and size control, I could go on about this…

We machine our valves and extensions from bar stock, which solves all of these issues but puts our maximum length of extension at about 70mm due to the depth of drilling the small internal hole, but it also guarantees a perfect match between sealing surfaces. Since the surfaces perfectly match (AND we use a special domed compression seal) our extenders and tube seal perfectly every time… no tape or any of that necessary, they just work…

So when you have valve extenders that just work, then it now also makes sense for the end user (or bike shop) to not have to carry as much about their inventory either… so you can have 2 tubes and some extenders at home and be able to service numerous depths of wheel…etc.

Long story short, we are confident that if you use our system, you’ll never give valve extenders another thought, and in that world, a single tube gives you the most flexibility at the point of use.

Josh, I’m not following 2 things you said…

“puts our maximum length of extension at about 70mm due to the depth of drilling the small internal hole” and…
“we are confident that if you use our system, you’ll never give valve extenders another thought”

So for those of us with 80/90mm wheels (Enve 8.9 wheels in my case), do you offer something that would allow us to use these new tubes? I’m in the market for latex for some late season racing.

20

Oh no… You can’t reformulate latex to leak less air without increasing rolling resistance. It’s now time for totally flawed amateur testing, endless “white papers”, and general panic around the Slowtwitchery Cauldron ™.

I’d quite like less leaky latex, but if it’s no faster than butyl then I’d stick with the leaky brass one’s…

Any testing of them done/planed to mitigate the above?