CameraMan

Yesterday afternoon about 3pm I packed my Airnimal in the back of my car.
The results were explosive.



The tires had just been pumped to 55psi from a track pump in the garage.
After a few hours in the sun they must have been a bit higher than that .

This was clearly a bit of a snafu.

jur

Hmmm...

Not very likely. That is most likely a simple casing failure.

For temperature to have a significant effect, you need to increase the temperature a significant amount in Kelvin. So if the track pump temperature was say 20degC, that is 293K. Pumping would increase temperature also, so add another 20deg, 313K. Now add yet another 20deg from sitting in the car, 333K. Total percentage difference from original pumping temperature, 20/313=about 6%.

6% is not going to pop your tyres. That casing was weak, or it is not rated for 55psi.

CameraMan

Both tires blew ! tubes and sidewalls gone
60psi rates tires.

LWaB

Crap tyres, you'd have no problems with a higher-rated tyre.

wahoonc

Did the other plastic parts melt? I have never had that happen to any bicycle tires, and that includes leaving high pressure racing tires mounted on rims in the car trunk, in direct sunlight in 100* temps in the Deep South. I think you just had a pair of inexpensive tires crap out on you. Better in the trunk than rolling down the road.

Aaron

BassNotBass

I've had the same type of failure on inexpensive tires, no out of the ordinary conditions, just while riding. I'd advise steering clear of Snafu tires and finding BMX replacements made by Maxxis (I like their Hookworms) or CST (their Cycleops are nice).

cplager

For a pressure only effect, you're right. For a pressure increases and the material becomes softer/weaker, a much smaller temperature increase can do real damage.

As others have pointed out, better tires may not have suffered the same fate.

Still Pedaling

I don't know anything about the technical aspects of the tires or anything about the brand, but I do know that heat from inside a car will not do that. I live in Arizona, and my bikes have been in the car when it's 100 + degrees outside with bright sun beating down, and my tires are pumped up pretty high. No problem my end and I must have cheap tires and tubes because I have a cheapo bike .

Cheers
Wayne

graycenphil

I would say if both tires blew a the same time, it had to be the heat, thought it may have been compunded by poor or damaged tires. I do know the airlines recommend that you let the air out of your tires before shipping the bike in the unpressurized cargo hold. Were the bikes inside the car, not the trunk? The tempurature could climb a lot higher, a lot faster, on a sunny day

CameraMan

Guess I had the worst case scenario here:

Cheap tires ( it was difficult to find knobbly tires for 20"/406 )
Black car
Black tires
Hot day
Car in direct sunlight
Hatchback with seats folded down with the rear tray only partially covering the bike.

BassNottBass - I will check out your recommendations as replacements; thanks.

kamtsa

It's global warming.

brakemeister

and what airline has unpressurized cargo departments ?

but back to the op ...
:-)

get some real tires :-) its a nice bike, so why save on the tires ?

HGR3inOK

In our area (central Oklahoma), it is not uncommon for tubes to pop on tires that have been inflated indoors and then left in a car parked in the sun for a while. This seems to occur more with road bike tires (>100 psi) than with hybrid tires (~60 psi). But it occurs often enough that we try to remember to warn our service customers to reduce the pressure in their tires if they are leaving their bike in a parked car for any length of time.

-HANK RYAN-
Norman, Oklahoma

BassNotBass

Well considering you're looking for knobbies the one's I suggested may not be for you. One of these may fit the bill though:

Maxxis Holy Roller
Maxxis Maxx Daddy
Kenda K-905 K-Rad
Schwalbe Black Jack
Schwalbe CX Comp HS 369
Schwalbe Jumpin Jack
Schwalbe Mad Mike
Schwalbe Moe Joe

CameraMan

Many many thanks for searching these out.
I've ordered up a pair of the Maxxis Holy Rollers - they seem to get good reviews for road, gravel and hard pack trails.

jur

I am sorry to pour cold water on the Holy Rollers - I have worn out numerous ones, they aren't particularly robust. The tread wears quickly and I have had casing failures also. They roll quite OK but I have decided to stop using them, just wearing out the one still on the bike, followed by one ready to go. After that, I will have to see.

Admittedly, these HRs are 451mm ERTRO.

BassNotBass

But then we know you're a torque monster, jur, and put more stress on a tire than the average Scooby.