PNB

Hi everyone,

I used (briefly) the search function but got no real useful hit.
here is the story:
I have a some 10Y old 26" fully which I use only occasionally and did not at all for a few years since I was on an expat mission.
So the tires (Schwalbe Nobby Nic Tubeless Ready) are still in pretty good conditions.
I refilled the sealant altogether maybe 3-4 times over the years (always Stan's) and the last times some 6-9 months ago.
Since a few weeks I noticed that both sides of both tires are constantly wet from sealant and you can notice some tiny bubbles.
The pressure loss over weeks is negligible and I'm wondering what's going on and if I should expect some major failure any time soon.

Thanks in advance.

tFUnK

Are they wet on the sidewalls, or at the beads?

PNB

I could be mistaken, but it really seems on the sidewalls, more in direction of the thread that the rim and quite all over the place.

Barry2 

Try reading this. Despite being a Stan's user for some time, I've had issues with Stan's not working on sidewalls.

Barry

PNB

I don´t see many similarities.
My tires are mounted since years, never lost significantly pressure nor doing it now.
Till a few weeks ago everything was pretty much unspectacular and then they started getting wet from the inside out, both tires, both sides. At once.

FBinNY 

I don't know the particulars of your tires, but am forced to wonder of maybe the sealant attacked the rubber coating inside the tire, and now it's "breathing" through the walls. In theory, the sealant would close this, but the nature of tire sealants is that riding drives it outward as the wheels spin, so they're very effective in the tread area. However, no natural action would replenish sealant at the side walls.

You can live with now since it doesn't seem to be causing more than minor annoyance. Or you can try your luck by removing wheels and laying them at a slight tilt and spinning them slowly for a while. Then repeat on the other side. No guaranties, but trying is free.

Canker

Some tires just seem to do that usually it is the thinner walled race tires. The rear tire on my hardtail does it. Doesn't seem to hurt anything other than needing the sealant checked more often so I ignore it.

Polaris OBark

You could just lay the bike on its side and spin the wheels a few times. Then flip it and do the other side.

It might be the side walls are just disintegrating and becoming more porous, but I have the same tires and they have been fine for years, albeit with orange seal.

It could be something as trivial as not shaking the bottle of sealant enough before replenishing it.

well biked

We see this fairly regularly in the bike shop. Not a good thing, obviously creates a situation where the sealant needs to be replenished more often, but other than that, it's a non-issue as long as you don't mind how it looks and the tires are still holding air. Canker is correct, it seems to happen more with lighter tires with thin sidewalls.

PNB

Thanks for the feedback.
Again, I'm surprised that it never happened before and started now that the tires are so old.
I´d just like to avoid a sudden failure when I´d possibly be in the middle of nowhere in case the tires are somehow deteriorated for whatever reason.

squirtdad

tires/rubber will be affected by oxidation,ozone etc over time so something happening with age is not surprising..... (kinda like my knees)

Hondo6

FWIW: various sources recommend that auto tires be replaces at either 6 or 10 years after date of manufacture. So yes, deterioration due to ozone/UV/etc . . . exposure is a real "thing" for tires of all types.

Up to you whether or not you replace the tires in question. But if they're approaching 10 years old, you might want to consider the cost of new tires vs. the inconvenience of a roadside tire failure you can't patch or boot. Or worse.

Troul 

are there any cracks appearing in the rubber? If you see cracking, they could be dry rotting.

PNB

Yes, I will replace them. Thanks.

ironwood

After two years of running tires tubeless some begin to leak. I've read that this is because running tires tubeless stresses the tire more than it would if you had tubes. When my tires began to leak sealant at the sidewalls I positioned the tire on its side so that the sealant would flow to that area, and the leak stopped for a while. I eventually gave up and scraped out all the sealant I could, and put in a tube. No problems now.

PNB

I can hardly believe that the tube would provide any relief from stress.
More likely with a tube you wouldn´t see any sealant leakage because there is no sealant in the first place.
Which also means that the tire still holds.

In my case I had tubes at the beginning.
After a puncture (snake bite?) it was very hard to replace the tube and I almost broke the tire levers because the tires sit so tight.
Thatś why I moved to tubeless.
Last Fall I wanted to put a winter tire with spikes (with tube) on the front wheel and, for the first time in my life, I gave up altogether.
With another bike/different rims and the very same winter tire I barely needed tire levers.
So I ended buying a new front wheel for the winter tire and it worked like a charm.