FMA Open tubulars - exploding inner tubes

[RetroGuy]

I have installed these tires on Duke Baccara tubeless rims with either butyl or latex inner tubes. I have also treated both the inside of the tires and the tubes with a healthy dose of talcum powder.

Yet, when the temperatures exceed 25 degrees centigrade and the sun shines on the rims the inner tubes explode - what could be wrong?

many thanks!

Stefan

[oldpotatoe]

Originally Posted by RetroGuy

I have installed these tires on Duke Baccara tubeless rims with either butyl or latex inner tubes. I have also treated both the inside of the tires and the tubes with a healthy dose of talcum powder.

Yet, when the temperatures exceed 25 degrees centigrade and the sun shines on the rims the inner tubes explode - what could be wrong?

many thanks!

Stefan

PSI? Tire blows off the rim? Something is amiss...

[ripvanrando]

Pressure gage could be wrong. The often are. You might think you put 7 bar but actually put 9 bar due to gage inaccurate.

I wouldn't put slippery talc on the bead/tire interface.

Is the tire blowing off the rim? I assume this is what you mean.

[Ryun]

Funny timing.
I had a set of fmb open tubulars on Bora WTO wheels. I was headed out for a ride on friday and pumped the tires up to 90-95. I left the bike leaning against the garage door. Came back out 15 mins later or so after changing and the bike was on the ground with the front tire blown off the rim. Tires had been on there for a month or so.. Wheels were hot to the touch and it was 90degs out but its been hotter. Not sure if the heat was radiating off the garage door made it worse but Id guess its been hotter in the trunk of a car.
Wrote it off as a freak accident or faulty tube until I saw this post.

Not sure how much the temp couldve raised the psi but thats an issue I havent had with another tire my whole time in Florida

[Ozz]

I'm not an engineer, but am having a hard time seeing how this could be a tube failure.

The tube is encased by the rim and tire....if the pressure increases, the failure needs to be at the weakest spot in the encasement, meaning where the tire seats into the rim....maybe a bad installation, or a bad bead on the tire that didn't seat properly.....when that fails, the tube blows out that weak spot.

That's my $0.02

[MikeD]

Pinched the tube under the bead, is my guess.

[Dead Man]

Originally Posted by MikeD

Pinched the tube under the bead, is my guess.

in a world of tubeless ready everything, this is def the most likely sitch. but yea, could also be bead release... does the tube pop inside the tire, or is the tire bead popping off the rim?

and im not familiar with all this ****, so ill just ask whats probably a stupid question, but are your rims hookless?

[Mark McM]

Originally Posted by MikeD

Pinched the tube under the bead, is my guess.

That's a likely scenario. Although, with widely varying tubeless tire/rim standards, there is also the possibility of rim/tire incompatabiity. For example, the Stan's Alpha 340 rims were notorious for blow-offs with some brands of tires.