I'm not a fan of Slime either. I didn't find them that effective the one time I used them and I don't like the extra weight of the sealant.

As a long time resident in the middle of the goathead hellscape, I've learned to resist pulling the thorn out once it is embedded in the tire. Without sealant, this tend to plug the hole and allow you to ride for a while without the tire going flat. Someone recently pointed out to me that this may be the wrong way to use Slime. He suggested pulling the thorn as soon as possible and allowing the air and Slime to escape. With the thorn in place, the hole is constantly opening and closing so that the leak never seals. Removing the thorn allows the hole to seal properly. I still don't like the extra weight but it might be worth a little experimentation.

That said, I did get put Slime tubes in my tires for a trip down to the Picketwire Canyon this last fall. This ride has been the equivalent of a slasher movie in terms of goatheads. I've gotten more than 60 punctures there in the past (I stopped counting at 60). But this year, I picked up some used tires (was going to just throw them away) and some Slime tubes as well as adding suspenders in the way of tire liners. Apparently this was enough to appease the goathead gods, as I didn't pick up a single goathead nor did my daughter. That's just unheard of!

Liners work and they don't necessarily cause flats by rubbing the tube. New liners tend to be a little sharp and a bit of sanding to feather the edges improves them but I haven't had any troubles for ages. Many road tires now come with a Tuffy like liner built into the tire and they seem to work well. The liner can't be used for dozens of tires but they do work.

Sorry but I just can't agree with you on this one. There is no difference in tubeless tires and Slime except that the Slime doesn't dissolve out of the tires over time. A tubeless tire without sealant is just a vulnerable to flats as a "regular" tire. There's still the weight of the sealant, heavier tires and slightly heavier rims to deal with.

Tubeless aren't flat proof as well so you may have to fix one out on the road or trail. Since you can't get them seated with a hand pump, you'll need to carry a tube which makes the mess of dealing with Slime trivial. And the tubeless tires I've helped mount at my local co-op were a nightmare to get off and get on. One of them took 4 people about 2 hours to get one off.

My experience with tubeless and with slime tubes is with different disciplines of biking (tubeless on mountain bike only; slime tubes with touring bike only), so to some extent I may be comparing apples and oranges, but I think there are differences. First the sealant itself is different. Second there is a difference in that there is movement of the tube against the tire. I have been told that movement makes the sealant less able to stay sealed. I can't say with any certainty that is the case, but I tend to believe it, at least with the still thorn in.

Weight of the sealant for my tubeless setup is 2 ounces per tire. A standard weight tube in that size is typically <8 ounces. The tires are pretty light. I don't have the weight handy, but the Stans Ravens that I use are among the lighter tires I have used in that size. They are the lightest MTB wheel/trie setup I have owned so I don't feel like there is much of a weight penalty.

I have not used tubeless in goat head country yet, but here in Florida I was getting a thorn flat once a week or more and have had none in the year or so since I started using them. I have not been even pulling the thorns out and the tires have been great wrt flats (none at all so far over a period where I might have had well over a dozen otherwise).

The Stan's No Tubes Ravens on Stan's wheels mounted easily and seated with a frame pump. When I had a spoke break (a stick snapped it off with the stub flush in the nipple), the tire came off and went back on easily enough. I understand that may not be typical of all or maybe even most tubeless setups.

They are reliable enough that for local mountain biking I carry no spare tube and figure the odds of needing one are really slim unless I run low enough pressure to be likely to burp one. On an off road tour I'd carry a tube and maybe CO2 just in case, but expect to not need it on the large majority of tours.

So my experience is not extensive or my conclusions based on a huge pool of data, but I figure it is enough that I am very happy to have tubeless on my mountain bike. I have not been tempted to go tubeless on my road bikes and I have not ridden the loaded touring bike in a few years (I have gone light enough to prefer a road bike for road tours).

I would agree that the sealant is different. Slime doesn't need to be replenished while most of the tubeless sealants I've heard about have to be refreshed and/or replaced every few months (3 to 6 seems to be the interval). Stan's, for example, tends to dry out over that time frame. The real question you have to ask is where does it go? The bicycle tire is a sealed system that is (mostly) impervious to liquids. If you were to fill your bike tires with water, you would still have water in them 6 months later. That's what makes tires such a good home for mosquitoes.

It took me a while to figure out where that liquid was going and it all has to do with the solvent used in tubeless tire sealants. Slime uses glycerol as the solvent while the tubeless sealants are mostly propylene glycol. The propylene glycol has a fair amount of solubility in the rubber of the tire and penetrates it. However, propylene glycol doesn't have much in the way of vapor pressure so any that ends up in the rubber stays there. Some will be ablated away with the tire rubber but, for the most part, it dissolves into the tire and stays there.

Glycerol doesn't do that so it doesn't need the constant refreshing.

I think you are underestimating the amount of sealant in the tires and slightly overestimating the weight of a standard tube. According to the Stan's tire installation instructions, a tire should have 1.5 to 2 cups of sealant per tire. That's 12 to 16 oz of fluid per wheel.

There's also the issue of the sealant dissolving into the tire. If you put in 12 to 16 oz of liquid and 90% of it goes into the tire and stays there and then you add another 12 to 16 oz of sealant, that adds up to a couple of pounds of weight after only a few months. And, as I'm not sure how much propylene glycol the tire can hold before it starts moving out of the tire due to rubber ablation, I can't say how much weight is added the next time you have to refresh the sealant.

The whole "refreshing sealant" thing is probably what bothers me about tubeless the most. Personally, I don't what the headache of having to do that on a regular basis.

I don't have tubeless and probably never will go that route. But I have been involved in trying to mount them and I see the paid mechanics at my local co-op when one comes in. Nobody really want to mess with them. It's kind of a toss up between which is more onerous: brake bleeds or tubeless install. I'd almost say they'd rather do a brake bleed and nobody wants to do that one.

The tire that give us all so much trouble was one that had an o-ring kind of bead on it. The "o-ring" was pressed into a channel around the rim and it was next to impossible to break free. We ended up having to use Park Tool's long metal tire levers and had to use them the entire way around the tire on both sides to pry the o-ring out. It was no easier to get the tire to seat either. It was one of the more challenging things I've ever been asked to do and that is saying a lot considering what kinds of problems we see every day at the co-op.

At the same time we had the guy's girl friend who had managed to burp the tire off her road bike rim by running it at 15 psi. That one was a bugger to get seated as well. We emptied the compressor a couple of times because we just couldn't get the tire bead seated. Sprayed sealant all over as well.

Basically, I wouldn't want either of those hassles in the middle of no where.

Interesting. Thanks for the explanation.

Stan's say 2-3 ounces per tire on the bottle and that is what I used.

The weight I listed was for a standard weight brand new 29er MTB tube that I had on hand. A quick check shows that other brands are in that ball park for standard weight 29er tubes in the 2.1-2.4" range. Some a little more and some a little less.

First, as I said the bottle says 2-3 ounces and the Stan's web site says:Also my assumption was that much of the weight doesn't dissolve into the tire. My thought was that much of it was lost to leakage. It hadn't occurred to me that it all stayed with the tire, but even if you are correct we are talking 2-3 fluid ounces not 12-16 ounces as you mentioned. Not sure where you got that figure, but everything I read from Stan's said 2-3 (fluid) ounces.

I figure a good bit of that 2-3 ounces must have escaped since I undoubtedly have had a dozen or even dozens of thorns that self sealed and I'd expect that a tiny bit is lost each time there is a puncture. I'd further guess that there is a bit of leakage at the bead with low-ish pressures and rock and root impacts.

Headache? I didn't find it to be. It is a matter of sucking up 2 ounces in the Stan's syringe, attaching it to the valve stem, and depressing the plunger. It does mean deflating the tire, but the whole process is easy, not messy, and takes a few minutes. Doing that once or twice a year is a just not that much trouble, especially when I would otherwise have been patching tubes often during that period.

Maybe it was because I used some very compatible tires and wheels, but it was a complete non issue for my tires. I have read that it can be a real pain, but it was really easy, easier than installing a tire with a tube where you need to take care not to pinch the tube. My results may not be typical, but I assure you it was completely painless and has remained so even when I needed to remove a tire to change a spoke nipple.


Sounds like a pain.

I was under the impression that it was around 4 ounces per tire but clearly says 1.5 to 2 cups (around 2.3 minutes) and the measure he uses is rather larger than 2 oz.

The question I have about the "leakage" is do you have to pump up the tires more often than a tubed tire? If you do, then the tire is leaking air which could account for the loss of sealant. But my understanding of the issue is that the tires aren't pumped up any more frequently than normal. The sealant will "dry" out even when the bike is in storage. That says to me that the sealant is being lost by other means.

Personally, I would be very concerned if the tires leaked air do to impacts. That implies that the tire isn't seated well and could easily burp off the rim. That would also imply that you could end up a ride with less air then you started. I've never found a tire going flat to be a plus on a ride. I might remove or add air on purpose but the tire shouldn't burp out air at random. But I really don't think that is the case.

"Tire coral" growth is my major concern which requires breaking the bead to remove the "coral". My other problem with the whole procedure is that it's a sealed system and really shouldn't need all this fiddling. They need to change the chemistry of their sealant so that they don't lose the solvent through the tire...which isn't good for the tire rubber either.

I've seen blistered tubeless tires which is caused by the sealant solvent breaking down the rubber.

When using the syringe in the video he says 2-4 ounces (the bottle and the website say 2-3 ounces). When you said cups and 12-16 ounces that assumed a standard measuring cup, but in the video that is a little cup that I think is probably 2 ounces. In this picture it is shown next to a pint bottle. Also it looks like there is a fill line so I suspect that the cup holds a bit more but is 2 ounces at the fill line.

I probably top off the tires every 3 days or so either way and have not noticed them needing more air than they did when I was running tubes. They may need a bit more, but I have not really noticed it if they do. A assume that the do lose a bit when they seal thorn puncture. Over the course of a six months to a year they get pumped up a lot of times whether they are running tubes or not.

Pure speculation on my part that the tire might lose some small amount of air at the bead. I have had no indication that there is any concern there. Any way since there none f that has been a concern in a year of daily trail riding I think those concerns fall into the category of looking for problems to worry about and ignoring the fact that I would have been patching tubes many times over that period.

All this fiddling? What fiddling? Adding some sealant once a year or maybe 6 months? That once compared to patching tubes many times over the same period. It is a couple minute job once or twice a year.

As far as coral, I saw no buildup of anything at all when I pulled the tire to change a spoke nipple and suspect that I will wear out the tires before there is any significant build up if there ever is. Time will tell I guess. If there is build up, taking the tire off once a year (more likely much less often) wouldn't break my heart. I might even wear the tires out before that happens.

That is bad if it occurs and if it does I may change my tune at some point in the future, but again I suspect that I will wear them out before that ever occurs, given that I ride my MTB pretty much every day and ride on pavement to get to the trails they don't last forever. I suspect the problems you mention would be worse for someone who rides the bike only once in a while, either because they ride other bikes more or because they just don't ride as often.

Of course as is always the case there are trade offs in all of this. For me and my usage of that bike I think tubeless is a slam dunk. The improved ride feel and elimination of pinch flats even when running lower pressure is a nice bonus.

To me, dealing with the mess and maintenance requirements of going the tubeless goop route isn't at all attractive.

I've never gotten the "coral" or "boogers" or whatever people choose to call the blobs of built up sealant, but that's probably because I stopped using Stan's quite a while back. TruckerCo Cream has been much, much better-- and is cheaper.

For the umpteenth time to the people that complain about mess: I recorded ZERO flats in over 10,000 road miles. Maintenance was limited to topping off sealant every few months and discarding of worn-out tires. That's it. If you can wrench on a bike in any capacity whatsoever, you should be capable of setting up tubeless with little drama. It's mounting a tire, not building a piano.

Of course, to those 60-miles-a-week folks... yeah, tubeless probably isn't for you.

Why so mad bro? lol

But seriously, that does sound pretty good. Does the stuff get stuck to the rim tape and such though?

It's just the same thing over and over-- people have never run tubeless, but they heard third-hand from one guy that it's a "hassle" so they discount it. The drawbacks are expensive tires, and a limited selection. That's it. Everything else lands in the plus column, in my experience.

And I really, really want it to catch on, gain in popularity, so the costs will come down. MTB tubeless tires cost half as much for 3x as much physical tire. I can't keep spending $90 on a pair of tires every 3 months. It's killin' me.

I think folks have the wrong idea about the "mess" and how much maintenance there is to do. The sealant is watery and just a little sticky. It rinses right off with water when freshly spilled. I have never noticed any mess that a quick water rinse didn't clear up. There just hasn't really been any mess and the whole deal was very much a low effort thing. It wasn't anything like the horrible mess that I found Slime tubes to be in my one and only experience with them.

I instantly went from having regular frequent thorn punctures to having no flats at all. Fixing one tube would about equal all the entire effort it has been so far.

In my case mounting the tire was about the same effort as mounting a tire and tube would have been since I used wheels that were already set up for tubeless and compatible tubeless ready tires. I have heard stories of them being difficult to get seated and requiring compressed air, but mine seated nicely with a frame pump.

To be clear... I have not toured on tubeless or even used tubeless on road tires. I would not hesitate to use tubeless for off road MTB touring, but have no idea of how it would be to use tubeless on skinnier tire setups.

On he road, do you guys lay the bike on side, upside down, or other when doing a puncture repair?

Fixing a puncture (changing tubes) is not a big deal. My wife can remove the wheel, Remove and check the tire for cause of puncture, replace the tube, inflate the tire, and remount it on the bike in about 20 minutes; less time for a front wheel. We've had up to 13 punctures on a 3-month tour; goatheads accounted for about half of those. We've also done other tours of about the same length, and had from 0-4 punctures. We ran Continental Gatorskins for quite a while, but have switched to standard Schwalbe Marathons, and really don't get too concerned about punctures. Tubes are patched in camp that night.

Just find a nice spot and lay the bike down. On this 6-week tour I had 4 punctures in the last 2 days of the tour from goatheads. The last one was going up the driveway to my mother-in-law's farm in Central California Actually this puncture made my day. As I was fixing the tire, my wife struck up a conversation with a non-English speaking man through his young son who was acting as interpreter. When the gentleman asked my wife, "why do you travel by bicycles"; she answered, "so we can meet people like you." The smile on his face made me very proud of my wife!



Or I just lay it down and have a 'garage sale".

With ~37-42 mm tires it was fairly easy to keep the Tuffy liner centered when mounting tires. & I guess that one could use a bit of cement to tack the Tuffy into place. Never had a Tuffy-induced flat during years of use.

Mr Tuffy is reputedly not perfect vs goat's head thorns...FlatAway/Rhinodillo might be better. If I lived in thorn country I'd consider tubeless esp since I have 559mm/26" wheels. Tubeless rims & the goo add weight but can't one compensate with lighter tire? That might give better ride & handling than heavy-duty Marathons etc.

Whatever happened to a decent quality tire, tube and keeping them properly inflated and checking them every so often for any issues? Flats happen, to me not so much but I keep my tires properly inflated and try not to ride like an idiot on bad roads and avoid potholes and visible stuff when I can. You don't need goops or heavy liners which can cause more flats or at least lumpy tires or anything of that nature.

I dig the idea of tubeless but it can be a touch of a hassle not by much and the gap is certainly lessening with new technology coming out. One of my future bikes is probably going to be tubeless though I really love my Challenge tires and might have a hard time giving those up.

Flats aren't so difficult to repair but can mess up schedule (esp non-summer) & in a group tour that gets multiplied. If it's cold or rainy it's not pleasant. Nice reply by your wife.

I rode $12 Nashbar street slicks, flat free for several years. Figuring that I was pressing my luck I went with Schwalbe Marathon Racers.

Got a flat the next week passing a construction zone at the local high school. The chunk of roof decking would have flatted a big truck tire. Nothing against Schwalbe....just proof of my general luck.

Two years later, same booted Schwalbe...no further leaks or incidents. Nothing will keep you from needing a flat repair kit on the bike. Be ready to use it.