Sealant - how long does it really last??

In my case, i put on a new tire 1 year ago (700c-28mm), with 35-40ml sealant, and half a year ago, i top up another 25ml through the valve hole. Yesterday i remove the tire, and realized there is around 60ml sealant still there.

According to any sealent instructions seems sealant will be complete dry after 6-9 month.

Have been tubeless user for 2 entire years, now all my 3 bikes (commuter, road, TT) in tubeless and i will never go back to clench and tubular. Those i ride 5000km/year and those i ride 500km/year, seem the same, it's just still there, seems the same amount after 6-9 month.

But seems i never encounter sealant to be complete dry out in any of my tire, i'd be rather it really dry so i only need to top up every half year. In this case I will need to consider to try to empty all the old sealant in tires before top-up, incase the old sealant to be lose effectiveness after half year.

I don't worry about my commuter, it spent 2 rear and 1 front tire every year, but

Considering i only ride around 500km of my TT bike every year, if i put in 30ml at the beginning, then 20 ml every half year, after 2 years there should be too much fluid inside...

Any experience?

 

How long sealant lasts depends on a few factors.

The type of sealant makes the most difference. The white-ish water/latex-based sealants like Stan's tend to dry up more quickly than the glycol-based sealants (orange or green). That said, Stan's works really well and it's what I use.

The weather you ride in makes a significant difference, with hot and dry conditions resulting in shorter sealant life.

The permeability of tires varies, with "tubeless ready" tires that require sealant allowing more evaporation than true UST tubeless tires (which work without sealant, though you should still use it for flat protection).

I imagine that how much you ride is bound to affect sealant life, but I haven't seen any real data on that.

On my own bikes, I typically only use 1/3 - 1/2 of the recommended amount of sealant for a given type of tire. This is plenty for them to seal properly, and some of the manufacturer's recommendations are just way too much (they're in the business of selling sealant, after all). Depending on the bike, I add more sealant every 3-6 months to make up for what dries out. I've heard that glycol-based sealants last longer, but I haven't had enough experience with them to say for certain. Either way, adding sealant is no big deal, as long as your valve stems have removable cores.

 

According to various tests I've seen on the internet Stans seals the best; so knowing that Stans recommends redoing the sealant once every 3 to 4 mos, I wouldn't go past 4 mos. For some reason all sealants last the longest in cold seasons but don't last as long in hot seasons, so probably every 3 mos in a warmer climate and 4 months in a colder climate.

I have no experience with these kinds of sealant, just what I've read over the years on the internet from users, so if someone else has better advice then go for it...please!

 

There are lots of factors, as I mentioned above. Another one is the pressure of the tires. The sealant in my fat bike tires lasts quite a while, probably because at single-digit pressures, there's very little air loss over time and little air is added from ride to ride. The less air exchange, the less evaporation of the liquid in the sealant. Although I should probably stick to some kind of schedule, the truth is that I generally add sealant when I can't remember the last time I did it.

 

Thanks for the reply. I am using Stans regular and realized it's still far less dried than the instruction. all my 3 bikes are road bike with 700c and 25-28mm tires, 60-80psi.
i wrote this because i was maintaining all my 6 tires all seems keep the same amount of sealant after 6-12 month of use, some only 500km in 1 year span while others rides 3000km in 6 month.
Now i realize if i put less sealant in will solve all my problems, and all the instructions 30ml for a road tire and top up every 6 month, i can do 20ml in the begining and 15ml every top up, i will never need to worry too much sealant in the tire anymore.
Thanks a lot.

 

For road tires that size, your plan seems good. I'm glad I could help.

 

After using Tubeless for three years I finally gave up. Yes flats are less common but with good tires they are pretty rare anyway. If you get a flat with a tubeless It is usually because something big has torn the tread it won't seal. So you have to have an extra tube and all of the paraphernalia along anyway. And doing a repair with all that messy sealant inside is nasty stuff. Also, it is HARD to get tires mounted on a tubeless rim while it is pretty easy to mount a clincher rim.

While I found that Orange sealant worked best, I changed to Finish Line grey when they claimed to be lifetime of the tire. That claim very soon ended since it depends entirely on the tire type and compound. It worked well enough but not as well as the Orange which had to be renewed. I would pull the tire off, wash out all of the old sealant and then fill it as if from the beginning. A lot of that dried sealant makes the sealing from a flat a lot slower than it should be.

In any case, I finally got tired of the mess and the much greater difficulty mounting tires and returned to clinchers with tubes.

 

Good to see that you seem to be doing better Tom. Anyway, I agree with what you said, your reasons are the same reason I never switched over myself, and then as a little time went on a few of my friends switched to tubeless and they all said the same thing you just said. I learned a long time ago that sealants just don't work that great unless it's a tiny hole that modern clincher tires avoid now anyways, but I use to run tubulars and ran into the same bull crap about how sealants would take care of leaks, real tiny ones yes, but otherwise no. I still had to carry spare tubulars when using the sealants, and now with tubeless you still have to carry a spare tube, it doesn't make sense to me other than being a tad lighter, but I'm not racing so lightness isn't an issue. A couple of my friends that made the switch have gone back to clinchers after their tubeless tires wore out, one switched back to tubulars but he's a weight weeny, and only one stayed with the tubeless system but he has a lot invested in it and doesn't want to switch back.

 

I haven't made the switch to tubeless on the road, mainly because I don't need any new wheels and I wouldn't buy wheels just to get tubeless. However, I do use sealant in my road tubes and I also used it when I rode tubulars and it has worked extremely well. The most common cause of road flats I experienced prior to using sealant was small pieces of wire (from steel belted tires) and thorns, which the sealant completely eliminated. I went for multiple seasons without any flats on the road. I have yet to encounter a puncture that Stan's couldn't seal, but I haven't gotten any substantial cuts, either. I currently run sealant in every bike I own because it works.

It seems like the latest trend in road tires is back to tubes, which doesn't surprise me. It seems that the real issues ares the higher tire pressure in road tires compared to off-road tires, and a lack of consistency in tire/rim dimensions. Road tubeless requires an extremely tight fit between the tire bead and rim and there are many tire/rim combinations that simply don't work (either too loose or too tight), which makes it a bit of a crapshoot. It's no wonder that adoption has been slow. The higher pressure in road tires simply makes the job of sealant harder. Any significant cut is likely not to seal.

OTOH, we run tubeless with sealant on our gravel bikes, MTBs and fat bikes and I would never go back to tubes on any of them. Tubeless works great at lower pressures and the sealant has eliminated the common thorn flats that can be a real plague in some of the places we ride. At any given time, I can check my MTB tires and pull a half-dozen thorns out of each of them, which the sealant has handled perfectly. Pretty much the only time that we ever experience a pressure loss is if I've forgotten to add sealant for several months. I carry a 2-ounce bottle with me and that has never failed to fix the problem.

 

I converted my winter commuter to ghetto-tubeless using a Kenda sealant. It seems to last considerably longer than Stan’s. I have no idea how well it actually works for flats. Hard to track what hasn’t happened.