How much PSI to explode a passenger car tire ?

[fastfredracing]

I occasionally get a few tires that will not " snap" on to the bead. It is almost always low profile winter tires, on wide rims.
I just mounted a set of China snow tires for a local autocrosser . I mounted them Monday morning, and aired them up to 75 psi , which is usually right at where I start to feel uncomfortable. One tire popped on, but the other 3 would not . I set the car next to the heater for the day, and one more popped, bu the other two would not go.
I aired them up to 100 psi and left the furnace on over night in the shop. I was hoping to come in and find them on , but no luck. It was getting late in the day, yesterday , and I really wanted to deliver this car back to Chris, so I got brave, and aired them up to 120. This is waaaaay past my comfort zone. they still did not pop. I tried driving the car, beating on the sidewall with a mallet airing up and down, and nada. I use tire paste, and they were lubed up very well, rim , and tire
I finally gave up and set the turbo heater 3 inches away from the trouble area on the tire, and within a few minutes each, the other two finally went .
My local tire vendor says they stop at 100. I wonder how much pressure a passenger tire can handle before it explodes ?
I was very careful to keep myself out of the line of fire while this was going on. I have seen a tire explode and leave the tire machine before and I want to be nowhere near that nonsense.

[javadog]

I've heard 250 psi in the past but I don't have any concrete info, nor would I go anywhere near that number. You also have to think about the integrity of the wheel and I wouldn't have done what you did.

Add into the mix that these were from China (not a fan of any of their products) and I would have let someone else handle this. I've seen truck tire/wheel assemblies come apart and, even in the safety cages they use, bad things have happened.

JR

[fastfredracing]

Yes java, I was not comfortable with this at all . I don't think I have ever gone past 100 psi in the past.
The fact that they were china tires made me all that more unsure . I was airing up from around the corner of the car, and kept my body completely out of the way just in case .

[billybek]

Could you have belted the centre of the tire with a ratchet strap to try to force the tire out while airing up to set the bead?

[Tobra]

Bill, that is my fave to set a tough bead

[GH85Carrera]

Back in the stone ages of the 1970s when I was autocrossing my 914 a lot the "hot" tire was a the Michelin XWX. The only Michelin dealer in Montgomery, AL that would order the XWX was a truck repair shop. I was there when one of the truck tires exploded in a cage and I thought a bomb had gone off. That tire destroyed the cage and no one was hurt but a lot of underwear was ruined.

My dad talked about a tire for a C-124 that exploded as they tried to air it up. It killed several airmen and destroyed the entire hangar.

[wswartzwel]

I have run into this with Motorcycle tires recently that were manufactured in the same place. I have found spraying the rim with soapy water, and the tires bead with UV2 ( a silicone based plastic protectant) seems to work better than regular tire lube... I also use a clip on chuck so I can stand back and disconnect the air hose from the quick connect at the other end and let the tire pressure escape through the hose to a safe level before going near the thing.

[Norm K]

[fastfredracing]

Above is not the problem I was having, I have that covered. The tire had already seated and was taking air, just the last 6 inches of the bead would not go over the rim lock on the wheel.
That ratchet strap trick works great for situations like the above video when the tire will not "seat " and take air

[fastfredracing]

Oh, and I use the Euro style white tire paste, and I wet it with a spray bottle of soapy water, this is how I do every tire. Super slippery stuff .

[Scott Douglas]

At those kinds of pressures I'd be worried about the rim breaking.
What kind of wheels were they?

[recycled sixtie]

Why should you risk your life and limbs to mount sub quality tires? Is there not a dedicated tire shop that could do this kind of work? Or do you have this kind problem with all makes of tire sometimes?

[fastfredracing]

It was a 2013 Honda Fit, his daily driver. Factory aluminum wheels. I asked a guy I know who runs a Sears auto center, and he said he has aired them up as high as 150 . No cage. Crazy.
Funny, Sears is where I saw a tire explode, and leave the machine . It went at least 15 feet in the air, and dented the steel roof trusses. Thank goodness , it did not hit the guy mounting . It would have probably killed him

[Scott Douglas]

Wow, if I were to witness that I don't think I'd go near the place again if that's how they operate.

[targa911S]

[sammyg2]

Back when i used to do split rims (what the hell was I thinking) I didn't have a cage so I would put the wheel under the legs of the car lift and use the weight of those legs to keep the split rim from taking my head off.

If i were pressuring up tires to 120 psi I might use the same technique.

[fastfredracing]

That is a good idea Sammy! I bolted them back on the car figuring that the real danger is if the wheel goes flying, that is what would take your head off .

[SeanPizzle]

i would start over again and throw a little soap on the inside of the rim. I have a CO2 bottle that I use at 125 PSI to quickly shoot air into the tire and seat the beads (attache chuck and quickly turn on the valve of the bottle).

[fastfredracing]

Ive seen those videos before, they will make you think twice for sure.

[manbridge 74]

Oh man, before someone kills them self, try letting air all the way back out of tire and run the wheel of tire machine back around the sidewall a few times. Really try and stretch the side with the tire machine wheel. And yes it's the rim piece which will fly up off the wheel before the tire will explode almost always. I've never had to use much over 40psi.