I live in southern Nevada, just outside of Las Vegas. Everybody knows Las Vegas gets hot. But to give you an idea of how hot it gets, when I park my bikes in my garage, I have to let some of the air out of the tires. I have actually had tires get hot enough the tubes pop. I don't know if it's just the rubber drying out or if it's expansion of the air due to heat that overpressurizes the tube. Either way, if I park a bike with 95-100psi in a tire and leave it long enough, I will come out to find it flat in just a few days. This has happened to me at least 3-4 times already this summer.

Anyone who has left their bike in a car without slightly opening windows on a hot summer day has noticed the same thing

If you ever see this immediately alert the authorities and consider breaking the window if you think the bike is in danger!

I've had it happen when left in a vehicle as well as in the back of a truck without a cover. Temps were around the 80s during a sunny day.
I wonder if tubeless is susceptible to the heat like such? Anyone experience it?

I have never left my bike in a car but that wouldn't surprise me. I would argue that a vehicle is a slightly more intense environment than a garage, but quibbles.

But on a related note, I recall an episode of Mythbusters that supposedly busted the "mytb" that soda bottle or cans can explode in a vehicle. I'm going to bust their bust because that has happened to me a couple of times.

cans in a freezing car will pop!

A couple of times at InterBike, the soles of my shoes started to get squishy, and I could feel the heat coming of the pavement burning my arms, on a plus side the ac at the gentlemen's clubs was very good....

How hot is it getting in your garage? For reference, if you pump to 100 psi (which is at the high end of what pressure you should be using) at 70 F, and the garage gets to 140 F, your pressure would rise to 112 psi. That should not cause the tire to blow off the rim. You don't explain what you mean by "tubes pop" but it you came out and they were flat with the tire still on the rim, then temperature was not the cause.

When I lived in Scottsdale once in a while it would hit 117 degrees. My garage was HOT, I mean Sonoran Desert Arizona summer hot and none of my tires "popped". Did they expand a bit? Maybe a little. My concern was that kind of heat long-term can't be good for tires so I changed tires after a couple of years even if they hadn't worn out.

Overkill? Maybe, but it just wasn't worth saving money versus a blown tire at speed, miles from home, on a 117 degree long ride.

You might think about getting a 'whirlybird' vent put up high in the garage, even if you can only install it at ceiling level if there's living space above it (there are types that can be 'angled-up'). My garage used to get up to 110F if I had the doors closed, I put one of those vents in the roof and now it rarely gets about 85F (typical summer outdoor temp in the shade). I got the whirylbird put in when the roof was replaced, single-story house. Just an idea if you own the house you live in.

My sympathies. We've had the hottest July ever in the California Central Valley (hit 111 at the house) and there are times my ebike can't recharge until it cools off after an afternoon ride. Too hot.

I have retrieved a bike from my car trunk to find the tires blown off the rims. This was pre hook-bead rim days and I have not had that experience since on modern rims, but still think it's possible. My bike locker at the office is in the sun all day and mid-summer I won't take chance on leaving a bike in it during a heat spell. Guessing it gets to 150 or more inside, on a triple-digit day.

PITA but stowing your bike with the tires partly deflated seems prudent, Just pump them to spec when riding, then release some air when stowing. PITA but much less than replacing a tube.

Wonder if tubeless goo cooks and loses moisture when stowed hot?

Slight quibble- how are you getting 112psi here? I'm getting 115 psi.

70F = 294 K
140F = 333K
ratio = 1.132

100psi => 114.7psi in absolute pressure
114.7psi * 1.132 = 129.9psi
129.9psi => 115psi in overpressure.
Technically it would be more than 115psi in overpressure because the atmospheric pressure would be lower in that heat

(yes I need to get a life)

I suppose, amazingly, It's never happened to me. And I use to pump my 23mm and even my current 25mm tires up to 125 - 135 psi. I don't routinely do that anymore, so lets not get into that.

I have traveled with my bikes in the car and fully inflated tires. Left in the noon sun during lunch stops. And I've left my bikes in the sun when at events. I guess I just haven't had the proper conditions in the 60 some years I've ridden.

how how in the garage? im in reno so not quite as hot but i do have the baking hot sun on my 3 uninsulated garage doors and it routinely gets up to 100F in there easily. been working on a piece of aluminum for the spitfure and it just sitting on teh work bench is hot to the touch even as late as 6pm. in those temps i just don't want to work in the garage.

by the way, i'm an 80 psi kinda guy with 23/25 mm tires.

I didn't say the tires blow off the rims. The tubes rupture. I'm seeing small splits, typically at a seam in the tube. They are mostly about 1/8-1/4" long when I pull them out. A few might be blamed on old tubes but the majority of my tubes are 2 years or newer.
I do need one (or two) of those. I'll probably do that this fall.
I can answer about the tubeless sealant for sure. It's not too bad so long as you ride the bike 2-3 times a week, but if you let it sit a week or more without riding, the sealant will dry up. I prefer tubeless because I have a well known history of punctures out here. Right now I'm running tubes in everything because I am getting ready to go out of town for a couple weeks, but once I get back, I'll be switching back over to tubeless on my two primary bikes.
I'm not really sure. I would hazard to guess in the afternoon sun, it's somewhere between 120-130 in the garage. I should put a thermometer out there, but I have to find one that reads >120*

Same thing happens on the road. I have started a ride with my tires (Kenda Gum Wall 27x1¼) at 90 psi and then just 30 minutes latter they were at 108 psi.

I'm in MD, and my south facing garage gets to 100-110 on the hottest days, the attic can be 130-140 in the same conditions.

you might be surprised how hot it is *not* in the garage. as i said...three doors all in full sun on a 100F day is only about 100 in the garage. doors are thin steel, little window that has UV filter on them. it surprised me. i now keep the doors open about a foot and the side door open all they way. it helps, but not much. i actually think more heat is from the hot engines once parked inside. they get to about 200F and all that heat has to go somewhere.

In other words... as hot as here. But at least during our "off-season" we don't have to shovel or scrape anything.

Several of my bikes are stored in non-air-conditioned conditions, but completely out of the sun, and I've noticed no notable change in tire or tube durability. If however a fully inflated bike or wheel is left in direct sunlight in our desert climate, I could see how intense radiative heating could cause a problem (having just loaded my bikes in the back of my pickup truck shell for tonight's 12 Hours of Sun City ride, and hoping the short time they're out there won't affect them much).

Ya, you get it. But I have had at least one of these tube failures on a bike in the carrier on the back of my car. Went for a ride. 30 miles, all good. Followed that up with some shopping in Vegas. Came out a few hours later and one of my tires was flat. At first, I wondered if I either picked something up on the ride or maybe a vandal punctured the tire, but there was no evidence of damage on the inside of the tire. Like these other failures, the tube simply had a small split on one of the seams.

I will NOT live in a place where the air hurts my face...

Yes. I have put my road bike with tubeless tires in the back of my car on a summer day and come back to find a tire deflated.

I had this happen on a day tour with tubeless. My tires were almost to max pressure when I left in the AM and it was only 14C but hit 36C in the afternoon. My tire popped of the bead but was undamaged. I just had to clean up the mess, put a tube inside and continue on for another couple hours. I was new to tubeless and just inflated my tires the same as I always did with racing clinchers/tubulars. Glad I was wearing baggie shorts over my bibs because I had to use them to clean up the mess.

I park my bike in the basement, the garage is too cluttered with lawn equipment and the cars. It does get quite warm in there, despite insulating above it a few years ago. Better than before though. Nice and cool downstairs, if that's an option for anyone.

Get a ridge vent.