Brother, respectfully, that is a very wrong statement, because I’m a Clyde-weight rider (meaning: high pressure) who happily rode 23c tubeless for 10 years, so “forget about it” cannot be the right assessment.

I’m into my second year on 25mm tubeless rubber at 90/95psi.

I also rode 25mm tires at 90-100 psi for a time. Orange Seal worked just fine, though I would occasionally need to top off after the pressure loss of bigger punctures.

My experience has been very similar to yours. Most notably, I agree with your observation that tubeless tires require more maintenance, however we can do it on our own terms. With tubes, you have no control over the location or timing for a flat repair. With tubeless, you can do the maintenance when and where it's convenient, then be much less likely to have a ride interrupted by punctures.

For checking the condition of sealant in the tire, there's a tool: a little plastic dipstick that comes with--or used to, at least--the big bottles of Orange Seal. To use it, you have to remove the valve core, but you don't have to unseat the tire bead.

28c more comfort, better rolling resistance, and on a modern rim more aero but also more grip and in theory less punctures due to larger contact patch and lower pressure

I've recommended tubeless syringes for years - they're great for adding and removing sealant without a mess and without breaking the bead. I've been using $10 jobbers from Amazon, but Park Tools recently released a (presumably) more robust version. The "needles" will clog a little more easily than the larger tubes that screw on to the valve stem body, so you do need to clean/flush with water more diligently and, even then, your can expect to replace them a little more frequently.

Those sound like reasons that you'd recommend ≤28mm in general, but not why you'd recommend against tubeless at >28mm.

I understand all that. However, what if the bike won't fit a 28? If 26 is the largest that will fit, would you not run tubeless? If not, why?

I'm using one of those cheap Amazon ones. So far, it's been fine. Flushing it out with water after use is part of my routine with that tool.

I do need a new one, and I think that I still have some money left on an Amazon gift card. Maybe I'll go nuts and get the Park version.

I appreciate good-quality tools, but sometimes I have a hard time justifying the additional cost.

I seldom pour sealant directly into the unseated tire. I have a syringe with a little plastic tube that fits over the valve stem (not the Park Tool version, just some generic one). The biggest reason I dislike Stan's Race sealant is that it has coarse grit that won't fit through the syringe nozzle. My process is as follows:

- Fit the tire over the rim, both beads
- With the valve core removed, seat the beads using my air compressor/tank
- Inject sealant through the stem
- Install valve core and pump up the tire to desired pressure with a floor pump
- Oscillate, spin, and bounce the wheel to distribute sealant. (The bouncing part is important.)

A few tips that I've found helpful for the most difficult step, which is seating the beads:
- Set the tire outside on a sunny day for a while to warm it up before installation
- Spray a little soapy water onto the beads to make them slippery
- After the initial burst of air, while pressure in the tire is still low, squeeze/massage the tire in several spots, then give it some more pressure

The moment I find more satisfying than probably anything else I do in my garage:
- When the last spot or two of the tire beads pop into place on the rim, sometimes with a sharp snapping sound

The thing that scares my trusty garage dog the most, with the possible exception of my shop vac:
- The one I mentioned immediately above. (Honey and I have very different reactions to bead seating)

Interesting. I never had any luck at anything over 80-ish psi. ☹️

Any holes simply wouldn't seal quickly enough, blowing sealant everywhere until around 40psi. Since going slightly wider (so a lower-pressure) I've had no issues. Maybe I was just unlucky in sealant choice.

I don’t know that it’s interesting as much as feature of your limited sample set of one. I mean, road tubeless has existed and persisted since well before the advent of the current wide rim and low pressure trend, and in fact it could be argued that tubeless gave birth to it, since the performance value of those early, high-pressure, road tubeless variants was so exceptional. Road tubeless as we have it today has come down over 20 years since the brilliance of UST; people forget, and how many road riders in the USA have even heard of Hutchinson, pioneers in tubeless, much less run their rubber? And those first Shimano wheelsets in ‘06? I don’t even know because nobody even talked about it in those days, but I bet they were 15mm internal and totally spec’d to run 120psi. Of course today we get a bunch of fanboys fawning over Conti GP5kS TLR, even though Conti didn’t enter the fray with a road tubeless model until late ‘18/early ‘19, nearly 20 years after Michelin into’d their first tubeless model. (That’s neither here nor there with regards to my point, just a sore spot!)

That road tubeless existed before the low-pressure trend and persisted to this day is because it works at high pressures. When American Classic dropped their Road Tubeless in fall ‘13, at 19.4mm internal, it was the widest tubeless rim in existence, designed around 23mm tires, and yet well short of the +20mm IWs that would enable typical pressures to drop below 100psi, let alone the sub-80ish you’re talking about.

My point here is that regardless of your experience, which may be described as the result of a number of various factors, one should not find it “interesting” that road tubeless works after more than 20 years in service. High pressure road tubeless was under the man in yellow as early as the 2004 Tour de France, with Thomas Voeckler on Telecom. Wanna guess what pressures he ran?

My TT bike is on 25mm as that's the max it'll fit. I still run tubeless, but mostly for the decreased rolling resistance. But also if I do get a flat, it'll most likely seal ok and get me to the finish without stopping.

Why not? As with most bike tech, I find it interesting. 🙄


Also interesting.

😘

You didn’t understand the meaning of quotes around the word?

Properly so.

www.cyclingnews.com presents the 91st Tour de France, 2004

The much lower pressures associated with modern, wider road tyres and rims simply makes tubeless even more effective. You can seal a bigger hole at 60 psi than you can at 120 psi and the loss in pressure while sealing a puncture will be less with a larger air volume. Stories of people getting sprayed with sealant are not happening at lower pressures. At 60 psi you just get a little spattering on the seat tube at most.

This is probably why tubeless became mainstream much earlier with mtb tyres with their much lower pressures and thicker tread.

I've been running regular tubed setups on my road bikes for years.
When I upgraded my bike over the summer to a one-year-old Giant Defy Advanced, it came with tubeless tires.
I looked forward to making the tubeless switch.
Anyway, they were very reliable for the short period I have used them.
What turned me off of them was when the bike sat for a month while I was out of the country, BOTH tires deflated and unseated from rims.
No big deal, just fill up w/air and be done with it, right?
Well, not quite....I went ahead and flipped bike over onto my bike holder and several ounces of goo spread all over the frame and floor....my bad....live-and-learn
As expected my bike pumps could not seat the tires back on the rim.
However I did expect to be able to use CO2 to get things seated though. Even after I removed the valve inserts my CO2 fillers could not seat the tires!
I had to go to the bike shop just to get them filled because only a compressed air tank could do it.
Anyway, when I upgraded my wheels I chose to go with tubed setup. I have never been stranded due to tire failure or field-unrepairable-flat in 10s-of-thousands of miles of riding. If I need a compressor just to reseat a troublesome tire when totally flat I'll pass on tubeless.

I wouldn't give up on tubeless due to a single problem that required an air compressor to fix. Not all tubeless tires work poorly, but some can suffer from bead stretch and make reseating difficult. Owning an air compressor, I don't have any problem seating new tires. I use only orange seal endurance sealant. I also use all hookless rims that are 23-25mm internal width and 28-30mm tires at 60 psi or lower pressure. I had problems with Michelin tubless tires and bead stretch after around 9 months of use. One of them became unseated when I let the air out to add more sealant. I could get the tire reseated with the valve core removed and a shot of air from my compressor, but it immediately unseated before I could install the valve core. That tire got trashed and I'll not be using any more Michelin tubeless tires. I've had no such problem with Pirelli P-Zero tires. I've removed a year old Pirelli tire from the front and moved it to the rear with no problem. Hooked rims are also less likely to have an unseating problem. I used Michelin tubeless with hooked fulcrum rims with no unseating problem.

Get a track pump with a reservoir

Narrower tires will try to pull themselves away from the rim bead if deflated, especially if your rim does not have a tire retention bump or ridge. I had that happen once with some 25mm Pro Ones and 20.5mm rims (NOX carbon rims). That was several years ago. No issue now on three road bikes and a gravel bike in years. Of course, this basically never happens on mountain bikes.

Funnily enough just reinflated some 25mm IRC tubeless on hunt mason-x which had been sitting around the garage for 6 months+

No issues at all. Suspect the sealant is in bad shape but I’ll have to hope for no punctures tomorrow as I don’t have time to re-do it.

edit: yep, still inflated this morning and 110km in the autumn sunshine with zero issues (@80psi pressure fans) :)

IME tubeless tyres will very slowly deflate when left standing for months (but only 1 month suggests a problem), but I’ve never personally had one unseat from the rim in that scenario. Right now my own Giant Defy is sitting in my garage on flat tubeless tyres. Occasionally I just pump them back up and this thread has reminded me to do that.

I found out a new quirk about road tubeless: the tire sidewall can become distorted over time. Because of this the tire slowly leaks air. This is on Schwalbe Pro One Addix.