What did I do wrong ?

[darth vadar]

Set off on a bike ride earlier, got half a mile and then I heard what sounded like a loud gun shot followed by an instant deflation of my rear tyre.

Upon inspection it looked like the inner tube had sort of 'exploded' forcing part of the tyre off the rim.

Was I just unlucky or did I inflate the tyre too much (about 100 psi) - although it says on the tyre wall that you can pump it up to that sort of pressure and beyond.

Just for info, it was a 23mm road bike tyre with inner tube.

Any thoughts?

Thanks.

 

[Nebulous]

Where was your bike stored? How hot was it?

I just had the same yesterday.

I reckon the tyre had heated up and increased the pressure beyond a safe level, forcing it off the wheel.

 

[ianrauk]

Was it a new inner tube? if so, you may have pinched the tube against the rim when putting the tyre back on.

 

[MontyVeda]

Where was your bike stored? How hot was it?

I just had the same yesterday.

I reckon the tyre had heated up and increased the pressure beyond a safe level, forcing it off the wheel.

Bloody weather

 

[darth vadar]

Where was your bike stored? How hot was it?

I just had the same yesterday.

I reckon the tyre had heated up and increased the pressure beyond a safe level, forcing it off the wheel.

Sounds like it could be that then.

I didn't do anything different than I normally do. It wasn't a new inner tube and it had been stored in the same place at the same sort of temperature. Only difference was that I pumped up the tyres but even then I managed a 15 miler on it without problems - until today.

I do have another theory which may have caused it.

My huge fat ar$e!!!

All I need now is the courage to try and repair it myself.

Thanks for the replies.

 

[lulubel]

Unless your tyres are antiques (like the ones Nebulous had problems with) or the tyre wasn't seated properly in the first place, I doubt heat would have caused it. Bikes are regularly stored and ridden in far higher temperatures here than in the UK, and it isn't something I've ever heard of happening.

 

[ianrauk]

Unless your tyres are antiques (like the ones Nebulous had problems with) or the tyre wasn't seated properly in the first place, I doubt heat would have caused it. Bikes are regularly stored and ridden in far higher temperatures here than in the UK, and it isn't something I've ever heard of happening.

Oh yes it does.
A few years ago one of the tyres (or should say innertube) on my bike exploded whilst it was stored in the conservatory. It near sent the wife into premature labour.
I posted about it on this very board and had a good few replies with others saying they had experienced the same (Exploding tyres not wife about to go into premature labour )

 

[lukesdad]

Unless your tyres are antiques (like the ones Nebulous had problems with) or the tyre wasn't seated properly in the first place, I doubt heat would have caused it. Bikes are regularly stored and ridden in far higher temperatures here than in the UK, and it isn't something I've ever heard of happening.

If you are putting 100 psi into tyres at 30 degrees thats fine, try putting 100 psi into tyres at 10 degrees and heat them up by 20 degrees and then check the pressures.

 

[lulubel]

If you are putting 100 psi into tyres at 30 degrees thats fine, try putting 100 psi into tyres at 10 degrees and heat them up by 20 degrees and then check the pressures.

If it's happened to people, I suppose it must happen, but it's similar to putting in 100psi in an airconditioned 20 degrees and then leaving the bike sat out in 40+ degrees full sun, which people certainly do here.

I suppose the problem comes if you're pumping your tyres up to max pressure all the time. If you're inflating to 100psi, but your tyres are rated to 130, there's quite a lot of leeway.

 

[Rickshaw Phil]

Unless your tyres are antiques (like the ones Nebulous had problems with) or the tyre wasn't seated properly in the first place, I doubt heat would have caused it. Bikes are regularly stored and ridden in far higher temperatures here than in the UK, and it isn't something I've ever heard of happening.

I regret to disagree. It does happen in some circumstances where the temperature has risen substantially since the tyre pressures were set and can also happen in cases where the rider has been constantly on the brakes for a long descent (I've witnessed this. Don't know how the rider avoided crashing as it was the front that blew).

In my old job with a car fleet business I even heard of it happening to car tyres when overinflated and left in the sun long enough.

 

[darth vadar]

Set off on a bike ride earlier, got half a mile and then I heard what sounded like a loud gun shot followed by an instant deflation of my rear tyre.

Upon inspection it looked like the inner tube had sort of 'exploded' forcing part of the tyre off the rim.

Was I just unlucky or did I inflate the tyre too much (about 100 psi) - although it says on the tyre wall that you can pump it up to that sort of pressure and beyond.

Just for info, it was a 23mm road bike tyre with inner tube.

Any thoughts?

Thanks.

In the end it cost me a new tyre and inner tube.

Still, you live and learn eh?

 

[Nebulous]

If it's happened to people, I suppose it must happen, but it's similar to putting in 100psi in an airconditioned 20 degrees and then leaving the bike sat out in 40+ degrees full sun, which people certainly do here.

I suppose the problem comes if you're pumping your tyres up to max pressure all the time. If you're inflating to 100psi, but your tyres are rated to 130, there's quite a lot of leeway.

There's nothing inherently different about the tyres from any others, they really are in remarkable condition given their age. Tyres are 28 mm with a 90psi rating. I pumped them up the day before early in the morning at about 8 degrees centigrade to 90. That's assuming my gauge on my track pump is accurate, many of them aren't. Then the shed at work probably was close to 40 degrees. Outside temperature was 26.

I tend to run at close to maximum. Roadbike I do 120 in the back and 110 in the front.

 

[simon.r]

I'm going back to ONC days here, so will happily stand corrected, but IIRC:

If volume is a constant, then pressure divided by temperature is also a constant.
So, assuming volume of a tyre is a constant*, pressure at 7 bar , temperature at 10c, the constant is 0.7.
If temperature rises to 30c, pressure rises to 21 bar to keep the constant of 0.7.

Am I right? That seems like a massive increase in pressure (100 psi to 300 psi) due to a 20 degree rise in temperature.

*I'd guess the volume of an inflated tyre will change slightly, but assume it's a constant to make this easier to work out!

 

[deanE]

I'm going back to ONC days here, so will happily stand corrected, but IIRC:

If volume is a constant, then pressure divided by temperature is also a constant.
So, assuming volume of a tyre is a constant*, pressure at 7 bar , temperature at 10c, the constant is 0.7.
If temperature rises to 30c, pressure rises to 21 bar to keep the constant of 0.7.

Am I right? That seems like a massive increase in pressure (100 psi to 300 psi) due to a 20 degree rise in temperature.

*I'd guess the volume of an inflated tyre will change slightly, but assume it's a constant to make this easier to work out!

The road temperature could be even hotter. However, thinking back to those dim and distant days, I would suggest that your calculations would be right if you used degrees Kelvin rather than degrees Celsius. 10 degrees C is 283 degres K and 30 equates to 303. I would recalculate your equation if I could find my slide rule but would suggest that pressure increase is not quite as high as you calculated.

 

[avalon]

I agree with lulubel, I'ts not unusual to have temperature changes of 20 degrees or more from one day to the next here and I will often leave my bike sitting in the sun for the day after an early morning ride. Having said that though, I did have the same thing happen to me recently. I put it down to an old folding tyre which needed carefully seating when fitting it, not being seated properly and blowing off the rim.