Author Topic: Tubeless versus Tubes - how well do tubeless hold air?  (Read 2484 times)

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Offline staehpj1

Re: Tubeless versus Tubes - how well do tubeless hold air?
« Reply #15 on: March 22, 2022, 10:04:36 am »
Your experiment was flawed, the tire is a sealed tire, there is no place for the liquid to evaporate away like with the paper towel thing you did.  On top of that, a small pin hole prick would probably only leak out maybe a gram or two at the most, so you would have to have a lot of pin prick holes to lose 3 or so ounces of sealant, and no one gets that many holes.  The sealant will dry out inside the tire, but what state does it leave when it dries out? sticky patches, and or dried CLUMPS of cured latex, the stuff is still in the tire, it just turned into another state.

This all got me thinking a bit and I looked up what I could find on the subject.  I found an article on cleaning out the crud periodically.  Their claim was that the water evaporated through the casing over time.  I can imagine vapor slowly passing through the sidewall.  Anyway I decided that since my tires on my MTB had numerous applications of sealant and zero cleanings I'd pop them off and check them out.  So far I did just the front one.

It popped off the beads by hand and was super easy to un mount and remount.  Other tires are undoubtedly much harder to mount and remove, but these (Stans Ravens on Stans wheels) are super easy.  I put them back on with my hands and the beads popped on without removing the core before the compressor got above 20psi.  Ithe air barely started flowing when they popped.  I have even mounted them with a hand pump before.

Anyway I popped the tire off and weighed it it weighed 617g (1lb 5.8 oz) including what looked like an ounce or maybe two of liquid still in the tire.  There was some sludge and small lumps.  There was a coating of latex over the whole inside. there was thicker patches of jelly like more watery latex in places.

I scraped and scrubbed until it was bare over much of the inside with a very thin coat of latex over some of the inside.It is hard to judge the weight but a very small fraction of the weight of a latex tube.  Any way the weight after all that was 536g (2.86oz.).  Even if you add a very generous allowance for the coating I didn't get scraped off a 29"x 2.2" tube is likely to weigh more.

I tried to figure out how much sealant I had put in that tire and my best guess is 8 ounces so I figure that a fairly substantial portion of the weight does remain, but nowhere near all of it.

It does seem that if that is a worry an annual cleaning out may be prudent.  Mine had been at six years since first install with no cleaning and some long spells just sitting while other bikes were ridden of I was doing other things.  I would guess that is pretty much a worst case scenario for build up of gunk in the tire.

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At the end of the day you have to do what you think is right for you, for me, I don't want to deal with trying to reseat a tire on the road because you can't so I have to carry a spare tube or two, I have to do that anyways whether it's tube or tubeless.  And with using the right tires flats would not be all that common if at all.  Of course, the argument would be that using the right tire you wouldn't get any flats in a tubeless either, and that's true!  But if you do have one, it's more of a headache with a tubeless set up.
We all pick our poison.  So far lately I have toured with tubes.  I tour ultra light these days and have beem on skinny road tires.  That has factored in and made me lean a bit more toward tubes especially since i don't own a road tubeless setup.

That said any tire I find pleasant enough that I choose it will get flats with some frequency.  In some parts of the country they are quite frequent even with a tire with some moderate flat protection.  Something like a gatorskin is about as far as I go toward flatproof.  Raiding on something like a marathon plus is my idea of hell.

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Another disadvantage that I forgot to mention is that the sealant is known for clogging valves.
Yeah, but I have not found it all that big of a deal.  Just a minor annoyance.

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I think the weight thing is false between the two types, by the time you add in sealant, special rim tape which is heavier than standard tape, you're pretty much a wash.
I tend to think that there is a bit of an advantage, but I am more interested in the supple ride that an effectively more flexible sidewall gives.  that and the protection from thorn flats.

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Running lower PSI using tubeless increases the chances of damaging the rim.
Running too low pressure with any setup does.  Tubeless allows you to go a bit lower.  You get to choose how low you go.  The only thing is that with a tubed setup you get pinch flats when you go low.

[/quote]Removing a tubeless tire after the sealant has dried will leave you with a sailor's mouth, although if you use a C clamp you can break the seal easily enough.
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Broke both beads easily with my fingers.  Zipped them off quickly and easily with one plastic park lever.  Easily put them back on with my hands.  I am almost 71 and have pretty bad arthritis in my hands and wrists (especially the thumbs).  My point is that it likely varies pretty widely with the particulat tire, rim, rim strip combination.  The even pop on the rime easy enough that I think I could do it with a mini pump.  I wouldn't want to rely on having to do that and would always carry a tube.

Also my experience is with one particular setup and it is a 29er MTB at that.   So it will likely not directly apply to a bike that I'd tour on.  It may be closer to apply for folks who tour with fatter tired setups.

I wonder about whether the easy seating of the beads on my bike is in part because of the very light sidewall and whether someone who opts for a more robust sidewall would have a harder time.  I'd have expected the opposite, but these tires pop right on every time i have tried them.  Granted they have only been popped off the bead and mounted a few times (mounted when new, popped off to fix a broken spoke when trail debris got into wheel, popped off to check sealant level, popped off today, and maybe some other reason I am forgetting)

Offline HikeBikeCook

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Re: Tubeless versus Tubes - how well do tubeless hold air?
« Reply #16 on: March 22, 2022, 10:33:15 am »
Your experiment was flawed, the tire is a sealed tire, there is no place for the liquid to evaporate away like with the paper towel thing you did....

The sealant will dry out inside the tire, but what state does it leave when it dries out? sticky patches, and or dried CLUMPS of cured latex, the stuff is still in the tire, it just turned into another state.

As I read these two lines they seem to be contradicting each other. -- "No place to evaporate" versus "The sealant will dry out inside" - How is that possible based on the first sentence?
Surly Disc Trucker, Lightspeed Classic, Scott Scale, Klein Mantra Comp. First touring bike Peugeot U08 - 1966

Offline staehpj1

Re: Tubeless versus Tubes - how well do tubeless hold air?
« Reply #17 on: March 22, 2022, 11:19:01 am »
Your experiment was flawed, the tire is a sealed tire, there is no place for the liquid to evaporate away like with the paper towel thing you did....

The sealant will dry out inside the tire, but what state does it leave when it dries out? sticky patches, and or dried CLUMPS of cured latex, the stuff is still in the tire, it just turned into another state.

As I read these two lines they seem to be contradicting each other. -- "No place to evaporate" versus "The sealant will dry out inside" - How is that possible based on the first sentence?
I think there is at least some drying.  I believe some vapor escapes through the sidewall.  I don't believe the tire just gain 4 ounces every time you add 4 ounce of sealant over the life of the tire.  I used to believe that most of the weight was water and escaped somehow.  Now after pulling a tire off this morning and weighing it,  scraping it as clean as possible and weighing again, I think the truth is somewhere in between.  Given that I don't know exactly how much sealant I put in or how much latex is left in the tire after scraping I don't have reliable data.  I do have a general impression though.  It is this...  Some goo builds up over time if you keep adding sealant.  Not as much weight as the total sealant you add, but enough to make it worth cleaning out the tire once in a while if you don't wear them out frequently and add much sealant.

I should note this was in Florida.  In the arid southwest they may dry out much more.

Offline froze

Re: Tubeless versus Tubes - how well do tubeless hold air?
« Reply #18 on: March 22, 2022, 10:15:00 pm »
Your experiment was flawed, the tire is a sealed tire, there is no place for the liquid to evaporate away like with the paper towel thing you did....

The sealant will dry out inside the tire, but what state does it leave when it dries out? sticky patches, and or dried CLUMPS of cured latex, the stuff is still in the tire, it just turned into another state.

You failed to read it correctly.  The stuff dried out leaving behind sticky patches and dried clumps, it's still there, it didn't evaporate away into nothingness, is simply dried up into another form.  I'm not sure what kind of example to use, try this one: let's say you have wet concrete, you can slush it around with a hoe, then you let it set for a day what happens to the cement?  You can no longer slush it around because it's hard, hard as a rock, but it's still all there, most of anyways minus some small amount of water that may have evaporated since it's outside, the cement simply dried out, the cement did not vanish into thin air.  I don't know how else to explain it to make it easy for you, but it's not that difficult to figure out what I said.

As I read these two lines they seem to be contradicting each other. -- "No place to evaporate" versus "The sealant will dry out inside" - How is that possible based on the first sentence?

Offline froze

Re: Tubeless versus Tubes - how well do tubeless hold air?
« Reply #19 on: March 22, 2022, 10:32:28 pm »
Your experiment was flawed, the tire is a sealed tire, there is no place for the liquid to evaporate away like with the paper towel thing you did....

The sealant will dry out inside the tire, but what state does it leave when it dries out? sticky patches, and or dried CLUMPS of cured latex, the stuff is still in the tire, it just turned into another state.

As I read these two lines they seem to be contradicting each other. -- "No place to evaporate" versus "The sealant will dry out inside" - How is that possible based on the first sentence?
I think there is at least some drying.  I believe some vapor escapes through the sidewall.  I don't believe the tire just gain 4 ounces every time you add 4 ounce of sealant over the life of the tire.  I used to believe that most of the weight was water and escaped somehow.  Now after pulling a tire off this morning and weighing it,  scraping it as clean as possible and weighing again, I think the truth is somewhere in between.  Given that I don't know exactly how much sealant I put in or how much latex is left in the tire after scraping I don't have reliable data.  I do have a general impression though.  It is this...  Some goo builds up over time if you keep adding sealant.  Not as much weight as the total sealant you add, but enough to make it worth cleaning out the tire once in a while if you don't wear them out frequently and add much sealant.

I should note this was in Florida.  In the arid southwest they may dry out much more.

You're getting lost on air vs water and what would take place inside a tire between the two.  You know air slowly "bleeds" out of a tire because you have to pump up your tires every day, but if you filled your tire with water instead of air the water pressure would remain unchanged for a very long time as long as there are no leaks, why?  water molecules are much larger than air molecules.  This why fabrics like GoreTex work, air passes through the fabric while the water just stays beaded up on the cloth not soaking through it. 

Most molecules that make up the air are smaller than water molecules (e.g. Ar is smaller than H2O), so it's easier for air molecules to diffuse into a container.  Most things that are "airtight" or "watertight" actually aren't, that is they permit some small flux of molecules. So, the answer comes down to practical considerations, if the leakage is slow enough not to matter for the intended use, then you can say it "doesn't leak". Most people would say that car tires are "air tight", but they go flat eventually, as air molecules diffuse through the rubber, or find their way through microleaks. In some situations, even much slower leaks than this are large enough to matter, in processes involving extremely high vacuum, rubber O-rings can't be used for sealing, because gasses diffuse through them.

That said, water vapor is a constituent of air, so something that is truly 100% airtight is also watertight: it does not allow water molecules to pass.  There are constituents of air that are smaller than water molecules, so presumably there is a hole size that will permit some air but no water.

Offline HikeBikeCook

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Re: Tubeless versus Tubes - how well do tubeless hold air?
« Reply #20 on: March 23, 2022, 11:45:36 am »
I guess the bottom line will be proven out at the end of my cross country trip. Since I am traveling with other riders, and one has the exact same bike but running with tubes, we can do a comparison on the number of flats encountered and how often we each have to top off our tires.

For now, at the start, my overall riding comfort has seemed to improve slightly with the tubeless in terms of handling, but that could just be tread difference. I have the weight savings, but that was not the goal. I had actually expected a weight increase because I added a Schmidt SON Dynamo and initially compared the wheel set weights to see how much weight the hub added. I was actually quite surprised and the huge weight savings from the tubeless -- and that accounts for sealant since the tires were sealed when weighed.

If I wind up inserting tubes along he way then I guess the "trend" may not be a good trend. I could also also save a few ounces by bucking another trend and swap my smart phone for a flip phone. :)

I will try and report back here once my trip is complete or if I return to tubes along the way.
Surly Disc Trucker, Lightspeed Classic, Scott Scale, Klein Mantra Comp. First touring bike Peugeot U08 - 1966

Offline froze

Re: Tubeless versus Tubes - how well do tubeless hold air?
« Reply #21 on: March 23, 2022, 01:25:29 pm »
Sun Dynamo for what? recharging rechargeable stuff I assume?  You won't be riding at night will you?  I thought about going that route myself but the cost of the system put me off, by the time you buy the dynamo and then have a new wheel built for it, I axed the idea after doing a lot of research.  A lot of people do use that type of system though, so it is a good system, I just decided to opt to a lower level system than that and went with a backpack type of solar system with a separate powerbank, it's a 3 panel system and combined with the powerbank the whole thing cost me maybe $65 on Amazon.  I've used it a bunch of times and it works great as long as there is sun!  But for days there is no sun I have the powerbank to recharge my stuff with.  The solar system can charge stuff up while riding too, I just tie it down on the top of my stuff on the rear rack and plug into whatever, but so far I haven't had to do that, I usually get to camp by 1pm so I just set it up and start charging, and most of my stuff I use isn't discharged more than maybe 33%, I have a low power usage iPhone SE I use just for this stuff, that phone and any lights I used are being charged at the same time and will take about 2 hours to charge.  That solar thing will charge up my phone as fast as a wall outlet!   

I think the Son Dynamo type of stuff is best for high power devices that drain batteries fast (maybe like for tablets), none of which I have, so the solar/powerbank combo made more sense for me, and a lot of touring people use solar stuff as well, I don't know what the percentage of touring people use one type vs another, but they all seem to be happy with either type.

Offline HikeBikeCook

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Re: Tubeless versus Tubes - how well do tubeless hold air?
« Reply #22 on: March 23, 2022, 01:51:02 pm »
I have backpacked extensively (60 years now) and thru-hiked the AT. I own a multi-panel solar charger as well, but the Dynamo Hub got me a net weight savings plus day-time running lights. I have it paired with an Anker power bank, which the dynamo keeps charged with daily riding even with the lights running. The power bank gives me  the ability to charge my devices for a few days even without a recharge.

I did not consider the cost issue, since I have learned that lighter weight and better tech always costs more than your typical off the shelf stuff. There is always a fine line between lightweight and durability. When you are traveling long distances, over weeks or months, you better understand the reliability and durability of your equipment.

I use what works best for me. It may be more than others can afford, or totally different that what others would choose if cost we no object, but I have no problem with that. I bike and hike to please myself and not to impress others, or try to sell them on my way of doing things. I am always glad to share why I bought something, why I pack a certain way, or how I lace my boots. Not everyone agrees with me or find my methods do not work for them. That is okay! I encourage people to look at many examples and pick and choose the parts that work for their particular needs. I am constantly evolving and adapting based on what I learn from others. I have tried a dozen different pieces of new equipment in the last several months and wound up returning over half of it, either because it wasn't an upgrade to me, or it was lighter but not durable enough.

Like they say in the long distance hiker world - Hike your own hike!
Surly Disc Trucker, Lightspeed Classic, Scott Scale, Klein Mantra Comp. First touring bike Peugeot U08 - 1966

Offline froze

Re: Tubeless versus Tubes - how well do tubeless hold air?
« Reply #23 on: March 23, 2022, 09:30:25 pm »
The newest Son dynamo hub weighs 477 grams according to Schmidt, the solar panel I got weighs 480 grams, so I don't consider 3 grams a big deal, the older Son hubs weigh more than the solar chargers do.

I like the Anker stuff, I got their smallest 523 Slim 10,000mah power bank because my charging needs are small, and it was the lightest weight power bank they sold at 208 grams, and their cheapest.

My only complaints with dynos are they are a more complicated mechanical device, which means something that could break down while camping/touring, the Son nor the Shimano are field serviceable unlike standard hubs; plus, they do have more resistance than a standard hub drawing about 5 to 6 watts when charging and about 2 to 3 when not, that is drag you're always pushing that you're not with solar.

There is more to consider when choosing between the two types.