How long do latex tubes last?
Do Latex Inner Tubes have a shelf life?
I’ve had a tremendous amount of trouble with latex inner tubes this spring. I’ve had the tubes for a decent amount of time. Can’t really remember when I bought them but I bought them as a 5-pack that was on sale. So they are probably more than a year old from my purchase date. As an example, I recently changed both the front and rear tubes (less than a week ago). I noticed last night that the pressure in the rear tire was lower than I would normally expect. I air my tires up before every ride and I generally have a rough idea of how much pressure I should see prior to airing up the tires. So the rear was a little lower than I had expected but certainly not flat. So I aired both up and went for a ride. 30 minutes into the ride the rear goes flat fairly quickly. Not a blow out. So no problem, I have an extra tube. As I’m changing my tube I hear the front tire pop and the sound of hissing air. The front is now flat too. After inspecting both tires, which only have a few hundred miles on them, I can find no signs of puncture. Lucky for me, a buddy comes down the same road a few minutes later and gives me his tube. When I get home I check both Latex tubes and they have punctures or holes. The rear has a smaller hole than the front. The front will hardly hold enough air for me to pinpoint the leak easily. It’s the one that popped while I was changing the rear. So not knowing exactly how the tube was inserted into the tire I have two possible locations on the tire to look for any punctures. I can find nothing wrong with either tire.
Any thoughts? If it were a pinch flat wouldn’t it have flatted sooner? The tubes were in for about a week and I probably had 200+ miles on them.
Answer from Challenge:
Heat and UV light are very bad for latex, so where the tubes were stored could be a big factor. Latex tubes deteriorate only if outside and exposed to light, sun, UV and extreme temperatures. There are tubulars that are 20 years old and still run great, so the tube has a long life when protected.
Problems are also caused by inserting the tubes (usually in a hurry) either under inflated, over inflated or when the talc we pre-apply is wiped off, then pushing the tube into the tire with a twist. The twist in the inner tube, when inflated to high pressure, creases the inner tube, making the tube prone to failure at the focus of the twist.
The keys during installation are:
1. lightly inflating the tube exactly to the point where it first forms its toroidal shape with no extra pressure;
2. making sure the tube is covered in talc so it slides through your hand (and inside the tire) and is not sticky;
3. as you press the second bead of the tire into the rim, make sure the latex inner tube is inserted into the tire cradle (away from the tire rim interface) and is NOT twisted;
4. when you get to the point where you are pushing the last bit of the second bead onto the rim, if the tube is trying to escape the tire, reduce the air pressure a bit until the tube can be pushed up into the tire and away from the tire/rim interface;
5. when you get the tire fully seated, inflate the tire to about 2 bar (25-30 psi), remove the pump and gently rock the tire back and forth through its entire radius to make sure the tire is truly seated and the inner tube is not pinched between the tire and rim somewhere; and
6. finally, fully inflate the inner tube.
For riders pairing Open Tubulars with a latex tube and aren’t experienced at mounting them, get a few rides on the Open Tubular with a butyl tube before installing the latex one so the tire can take shape and the installation is easier than with the flat tire.
My bottom line on latex tubes? They perform incredibly well if stored and installed properly. However, it is incredibly difficult to impress on the average consumer (and sometimes even mechanics) that you must sacrifice a bit of extra time and effort while installing them to ensure they perform their extraordinary deeds and live a long and healthy life inside their tire/rim cradle.
All of this explains why we have virtually zero problems with latex inner tubes in our tens of thousands of tubular tires sold every year. Once they are safely sewn into their nice, comfy cradles they do wonderful things and live a long and vibrant life.
— Morgan Nicol
Challenge Handmade Tires
Answer from Vittoria:
The use of latex tubes as a performance component to both tubular and clincher tires is more than just a lighter weight tube. Latex can add to the performance by allowing the tube to expand by up to 7 times, compared to only 1.5 times for butyl. This will allow latex to deform to external pressure that attempts to penetrate and puncture. This feature of latex gives it greater durability in terms of puncture resistance and also decreases the rolling resistance by allowing greater flexibility in the tire’s casing. If paired with a cotton casing such as Vittoria’s famous cotton Corespun casing found on our Corsa Tubulars and Open Tubulars, the benefits of performance and durability are definitely increased.
As for shelf life, latex is a naturally very porous material that does “leak” air over extended time. The higher the air pressure of the tire, the greater the loss of air. That being said, Vittoria also recommends to use a sealant to coat the interior wall of the tube to prevent the natural air loss, such as Vittoria Pitstop. This will also increase the overall resistance of puncturing under normal conditions (not tire gashes or significant punctures). Also, latex is more susceptible to outward elements such as UV light, oils, and braking heat.
So, for its somewhat delicate nature, latex is a very durable option to use as a tire performance enhancer, and [when] used with a sealant can extend its natural durability.
— Vittoria S.p.A.
A couple of things I’ll add to this. First, a latex tube generally comes packaged inside a plastic zip-lock bag inside of the box. Since latex is so sensitive to ozone degradation, keep them sealed in the bag until use. That also means leaving them in the bag when in your spare-tire bag on your bike and not allowing tools and other items inside the bag to cut or abrade the bag.
And the surest way to get a latex tube crispy is to leave it in the sun. It has no carbon black in it to protect it from the elements. If you ever had a slingshot as a kid made with surgical tubing and remember how soon the tubing would crack and break if left outside, you know what I mean.
Latex tubes are much less susceptible to punctures and to pinch flats than butyl tubes, but they are more prone to degradation from the elements. I do not know what happened to yours, but I assume that you ensured that there was nothing sharp on the rim bed — the rim strip was in good shape and covering the spoke holes and valve hole well and no spokes sticking up or sharp bits of aluminum or anything else floating around in there.
However, if you had had sealant in there (and not all may be ideal for the long term; some sealants are purported to “burn” latex inner tubes) — and the hole was on the side facing out toward the tread, I would bet that you would not have had the leak in the first place.