[Santoshbhat]

Originally Posted by reignofchaos

That's really scary! That is a sure shot case of sidewall failure. It appears that you might have gotten tyres from a bad batch or tyres that are really old. You might want to get rid of all those tyres to be safe.

I think so too. But the tyres aren't really old (week 32 of year 2016.) But yes they are of a single batch.

Originally Posted by androdev

That's a pretty scary incident. I am glad nothing bad happened. I almost replied to your last post about switching to non-RFTs but decided not to post it. Many forum members have posted in favour of switching to non-RFTs on this forum but it is not a good idea if the car is used for highway runs. Btw, this can happen with RFT also (I remember an old post by Turbonator having faced similar damage with an RFT).

Can you please post full tire spec (DOT code, date of mfg, especially load rating, etc.)?

Tyre size & spec Pirelli P Zero Rosso 245/50/R18 100W same as stock Pirelli Cinturato Runflat. Dot code : DOT 51 V2 B178 3216. Load rating 800 kgs at max 51 psi. One thing I noticed was that these tyres, visually looked to be a bit underinflated at rest compared to the runflats at the same pressures. The sidewalls looked to bulge out a bit at the contact point. I thought this was due to the fact that these are not RFTs. These are W rated tyres meant for high speed cars https://www.pirelli.com/tyres/en-gb/...et/pzero-rosso. W rated tyres are supposed to be good for 270 kph and these gave way 120. All I can say is, I am glad it gave way at 120!

Originally Posted by Hayek

Really scary and I think you and your dad dodged a bullet. A side wall failure at high speed is a worst case outcome. Personally, I think sticking to run flats makes sense - they are intrinsically safer than ordinary tubeless tyres.

Btw, my X3 20d shows the pressure in each of the tyres while driving. Does your car have a different system?

I think after this incident I don't have the guts to drive on these tyres. I will be switching back to runflats. But what about other 99% cars that run on normal tubeless? Or are you saying BMWs + tubeless are not made for each other?

As Akshay has clarified, your car has the new active TPMS system. My car has the old passive one that depends on ABS sensors that detect change in rate of rotation of tyres and give out warnings. I think I will have to get one of these. I hate these external systems that have to be plugged in constantly.

Originally Posted by sumeethaldankar

Sorry to hear the incident but glad you are ok. Weren't those tires brand new? I am sure they would be under warranty. Hopefully just one bad tire was the cause. I think the you should file for a warranty claim. Such a expensive tire should not just give up under normal usage.

Tyre warranty is extremely difficult to enforce. They wriggle out easily saying external damage under inflation etc.. I will try. But I am not very hopeful.

Originally Posted by Akshay1234

Santosh - That was a close shave, what are the load ratings on your tyres?

Mentioned above. What's your take on the pressure? 34 psi is OK?

Originally Posted by dkaile

Sad. What about the rim? I hope there is no rim damage. Get the tyre replaced with a similar one and make peace with it.

Cheers...

I hope the rim is OK. I think what happened is, first the sidewall developed a bubble. Then the bubble expanded and got cut. Air escaped and by the time I came to a halt, the weight, speed and lack of air shredded the tyre. I don't think the tyre got burst all of a sudden as I did experience and sudden loss of control neither was there any explosion as such. The air had leaked and it reached a point where the steering started to wobble and the tyre collapsed. It wasn't really gradual but wasn't very sudden either. I will need to get the rim inspected thoroughly though.

I don't think I have the courage to continue on these tyres now. The remaining ones are of the same batch and if one gave way, there is reason why another will not go the same way. And given that the failure happened pretty early in the tyre's lifecycle, I am inclined to believe it was defective. I will never be able to enjoy the drive with this fear lurking in the back of my mind. Its a bad deal. I'll have to swallow the bitter pill and move on.

[androdev]

Given that it started with a bubble it certainly seems like a manufacturing defect to me. 245/50 is not such a low profile and you didn't go through any bad patch. So we can't blame tubeless design. I don't think even RFTs will prevent this type of failure, I have seen few incidents like this with RFTs posted on this forum itself. They are safe in case of puncture or loss of air without serious damage to the sidewall.

I am increasingly convinced that maintaining moderate speed is the only effective strategy.

You will not like it but 17" wheels with RFTs will offer better protection.

Ironically, I just switched to 255/40R19 from 235/55R17 but I have definitely made up my mind to drive slow. Had enough close calls and the fear has firmly taken over.

[Nikhilb2008]

Originally Posted by androdev

Given that it started with a bubble it certainly seems like a manufacturing defect to me. 245/50 is not such a low profile and you didn't go through any bad patch. So we can't blame tubeless design. I don't think even RFTs will prevent this type of failure, I have seen few incidents like this with RFTs posted on this forum itself. They are safe in case of puncture or loss of air without serious damage to the sidewall.

There is no evidence of a bubble. It's Santosh's assumption that a bubble developed which opened up.

Building up theories based on assumption and then declaring it is a manufacturing defect is not appropriate by us senior BHPians. Let us not fall to the standards of current media outlets.

Santosh, I must say, you're very lucky. I wouldnt say that you were unlucky, but you were very lucky. Whatever happened cost you some money, a lot of time and some hassles, but at the end of the day, the result is still ok. You and your dad are safe, car is safe, you got back home the same day and you've taken a decision which is probably a wise one.

This kind of a failure is very unusual. Normally, when there is a hit, there are some marks on the wheel. In your case, I dont notice anything.

If you had a puncture which caused the air to leak and reduce pressure in the tyre, the object causing the puncture would have fallen out. Not finding a nail or object doesnt rule out the possibility of picking up a puncture.

You've already mentioned that the on board system didnt give you an indication once when the pressure was down to 20 psi. Driving a heavy-ish car with 22 psi or so at 80-100kph is a recipe for disaster. It might be a worthwhile option to use an aftermarket TPM system in your car to keep track of pressures all the time.

[androdev]

Originally Posted by Santoshbhat

Tyre size & spec Pirelli P Zero Rosso 245/50/R18 100W same as stock Pirelli Cinturato Runflat. Dot code : DOT 51 V2 B178 3216.

First two letters of DOT stand for manufacturing plant code. 51 is Pirelli China.

Originally Posted by Nikhilb2008

There is no evidence of a bubble. It's Santosh's assumption that a bubble developed which opened up.

Building up theories based on assumption and then declaring it is a manufacturing defect is not appropriate by us senior BHPians.

It is just a theory. I am open to other theories. Most common causes of such sidewall damage: you either hit a bad patch of road, you have a lower spec tire or the tire is defective. On cars with TPMS (even if it's ABS based), it is unlikely to have a catastrophic failure due to a puncture or under inflation.

[dkaile]

Indian roads ideally require harder rubber with higher profiles like MRFs or even Bridgestone even if you need to sacrifice a little on road noise and grip.

[Akshay1234]

Originally Posted by Santoshbhat

I think after this incident I don't have the guts to drive on these tyres. I will be switching back to runflats. But what about other 99% cars that run on normal tubeless? Or are you saying BMWs + tubeless are not made for each other?

As Akshay has clarified, your car has the new active TPMS system. My car has the old passive one that depends on ABS sensors that detect change in rate of rotation of tyres and give out warnings. I think I will have to get one of these. I hate these external systems that have to be plugged in constantly.

I think it was just a one off incident, where your tyre probably hit some shrapnel or a sharp object. Very possible on our highways, and its unlikely you would have noticed it too. Best to buy a new tyre and not overthink it. The pressure you filled was fine too, and not that you were driving too fast to heat up the tyres too much.

[venom_op]

Originally Posted by Santoshbhat

As Akshay has clarified, your car has the new active TPMS system. My car has the old passive one that depends on ABS sensors that detect change in rate of rotation of tyres and give out warnings. I think I will have to get one of these. I hate these external systems that have to be plugged in constantly.

My car has only ever given me an actual warning only once and that was when it had deflated too much already as well. Feels scary. You believe when you book a expensive car like this with TPMS, it'll notify you with even slight changes!

I'm now looking at getting a Nonda TPMS for more reliability. They're a kickstarter project on Indiegogo. They seem to sync with your phone and give you live updates. Plus it looks better than the Blaupunkt. Give them a look. I'll probably ask my brother to get one from the US.

[Santoshbhat]

Originally Posted by Nikhilb2008

There is no evidence of a bubble. It's Santosh's assumption that a bubble developed which opened up.

Building up theories based on assumption and then declaring it is a manufacturing defect is not appropriate by us senior BHPians. Let us not fall to the standards of current media outlets.

I haven't really labelled the tyre as defective, but can't rule out the possibility. I am just trying to figure out what exactly happened, hence the theories. I had left for Belgaum on Monday. Again before starting, I had checked pressures : 34 psi all round. Reached Belgaum and parked the car in the basement. It sat there all week. On Sat Morning I checked pressures again : 34 psi all round. None of the tyres had lost even a small point of pressure. I am stunned as to how the air leaked in those 40 kms. Quite possibly low pressure caused the bubble in the first place. But there is no denying the fact that both me and dad heard the pop about 10 mins before the final shred.

I have once again checked the tyre very very thoroughly and there is absolutely no evidence of any nail, sharp object or any impact on the tread part. Its a brand new tyre and its absolutely clean. Since it was running on a clean highway tarmac before the shred, its absolutely clean, not even a small pebble or dust on the tread.

I am sorry but I have come up with another theory. My tyre change got hastened by a puncture I suffered on one of the RFTs. I had just reached Bangalore after a highway journey and the TPMS gave off a warning. The pressure was 10 PSI. I then inflated that tyre using my Michelin inflator and completed the remaining few kms or so. I changed all 4 tyres afterwards because I did not know for how long I ran on that tyre in the deflated state and did not want to take a chance. The car sat in my garage for 1 week before I went to change tyres and there was no pressure drop in that period. I also checked the tyre for any nail or puncture but could not find anything. I found it strange as I could not figure out why that tyre lost pressure. Mind you before that particular journey also I had checked pressure as usual. When I changed the tyres, the tyre guy told me that one of the valves is defective and needs to be changed. I then realised that that was it. That's why it lost air! The remaining three valves weren't changed. Maybe another valve developed a leak yesterday afternoon.

I am really confused about what to do. I spent a hefty sum for the new tyres and am in no mood to do it all over again. What do you think about my valve theory? Is it possible for valves to lose air like that all of a sudden? If thats the case, I can get another tubeless Pirelli and change all remaining valves and get on with it.

Clicked a picture of the ruptured sidewall. Looks very thin to my untrained eye. Your thoughts?

[shibujp]

Originally Posted by Santoshbhat

I haven't really labelled the tyre as defective, but can't rule out the possibility. I am just trying to figure out what exactly happened, hence the theories. I had left for Belgaum on Monday. Again before starting, I had checked pressures : 34 psi all round. Reached Belgaum and parked the car in the basement. It sat there all week. On Sat Morning I checked pressures again : 34 psi all round. None of the tyres had lost even a small point of pressure. I am stunned as to how the air leaked in those 40 kms. Quite possibly low pressure caused the bubble in the first place. But there is no denying the fact that both me and dad heard the pop about 10 mins before the final shred.

I have once again checked the tyre very very thoroughly and there is absolutely no evidence of any nail, sharp object or any impact on the tread part. Its a brand new tyre and its absolutely clean. Since it was running on a clean highway tarmac before the shred, its absolutely clean, not even a small pebble or dust on the tread.

I am sorry but I have come up with another theory. My tyre change got hastened by a puncture I suffered on one of the RFTs. I had just reached Bangalore after a highway journey and the TPMS gave off a warning. The pressure was 10 PSI. I then inflated that tyre using my Michelin inflator and completed the remaining few kms or so. I changed all 4 tyres afterwards because I did not know for how long I ran on that tyre in the deflated state and did not want to take a chance. The car sat in my garage for 1 week before I went to change tyres and there was no pressure drop in that period. I also checked the tyre for any nail or puncture but could not find anything. I found it strange as I could not figure out why that tyre lost pressure. Mind you before that particular journey also I had checked pressure as usual. When I changed the tyres, the tyre guy told me that one of the valves is defective and needs to be changed. I then realised that that was it. That's why it lost air! The remaining three valves weren't changed. Maybe another valve developed a leak yesterday afternoon.

I am really confused about what to do. I spent a hefty sum for the new tyres and am in no mood to do it all over again. What do you think about my valve theory? Is it possible for valves to lose air like that all of a sudden? If thats the case, I can get another tubeless Pirelli and change all remaining valves and get on with it.

Clicked a picture of the ruptured sidewall. Looks very thin to my untrained eye. Your thoughts?

Sorry to hear about this incident. Regarding the valve, I had an incident when I topped up air pressures one night only to find one of the tyres flat the next morning. Took it to the tyre repair guy and no puncture was found. According to him, the valve stem did not return back after I removed the compressor nozzle allowing the air to leak out. The valve then did great service for the next 20k kms.

As you have expressed in your earlier post, I am not quite sold on going back to RFTs as tubeless tyres seem to do fine in a lot of other high performance cars. However it is always a nag at the back of your mind expeciallty at high speeds.

Drive on,
Shibu.

[Nikhilb2008]

Santosh, it is always recommended to change valves when you change tyres. If the tyre shop did not change it, then that's a mistake. ALWAYS ALWAYS change the valve while changing tyres to ensure your new tyres dont have a weak spot.

Also, looking at the sidewall pic you posted, it looks like it was running on the sidewall (due to lack of air) for a bit before it opened up. I wish I could see the tyre itself in real life. Can examine to my heart's content! :

Normally, the sidewall gets rubbed/burnt due to the weight of the car and friction with the rim. It becomes weak. In your case, it has continued for a bit (like you say, maybe 10 minutes) and then finally given way.

Is there any possibility of the on board TPM Sensor failing?

[jalajprakash]

Originally Posted by Santoshbhat

What do you think about my valve theory?

Santosh, I had a similar experience on 1000km run Michelin XM2s on an Innova, one tire lost pressure while on the highway for no apparent reason and the second time, it lost pressure just standing outside my office for 6 hours. Swapped out for the spare and took it to a tire repair shop and no puncture could be found and the culprit ended up being the valves. Had them change out all the valves to brand new ones and the car has been running problem free since.

While you can travel on RFTs for 100 kms even after tire burst, what I have observed from stories shared among my friends is that RFTs also develop a tire bubble/burst more often than tubeless tires just because of their rigid and non-forgiving build nature. Even in your case, where you had to travel 450kms after the puncture, RFTs wouldn't have helped.

Get those valves swapped out for brand new ones and you should be good to go.

[the_skyliner]

Sorry to hear about the incident, Santosh. However, glad to know that you are safe.

That stretch of highway is super smooth and clean so no question of hitting a pothole or alike.

I remember your post about switching to tubeless and like androdev, I too thought of posting in favour of RFTs. Yes, they are not foolproof but definitely safer than tubeless and especially on a heavy and high end car.

Anyhow, it would be safer to replace all remaining tyres along with valves otherwise it will always be back of your mind and that's not a good thing.

Usually, valves should be changed with each tyre change. Surprised that you tyre shop didn't recommend that.

[Santoshbhat]

I visited the tyre shop with the cut tyre. As expected he started dishing out impact theories blah blah blah. Ended that discussion. I had zero hopes of getting any replacement under warranty. Asked him why valves weren't changed. He says they replace only if they are 'damaged'. Asked him how he identifies damaged valves? He says by seeing if the rubber is cracked.

I've been debating this in my mind since yesterday (Its all I can think about right now). RFTs are safer during blow outs no doubt, but there is no statistical data that supports the theory that RFTs are less prone to sidewall damage. In fact the more I read, the more I find that RFTs are more prone to sidewall cuts due to lack of flexibility. 99% cars on the road run on regular tubeless be it heavy cars or light cars. I've experienced the run flats and the tubeless tyres on my car and the difference is huge. The stock Pirelli Cinturato RFT which is probably available off the shelf from the dealership is actually an eco/ green/ low rolling resistance kind of tyre. After it wore down to some 50% it just wasn't able to cope with the torque from the engine and started to wear weirdly down the middle. In fact the lack of grip made the ESC/TCS system cut the power with the ESC icon flashing on the console. Ever since the tyres were changed the power was being put down on the road beautifully, not to mention the ride. The ride was truly premium car.

I feel there had to be an air leak (probably the valve, there is no puncture) which caused the sidewall to collapse, the TPMS did not register it, I continued driving and the tyre got shredded.

I've decided to give it another go. Call me foolhardy, brave or plain foolish. I'll try getting one of those external TPMS systems and see if I can monitor pressures that way. And yes change all valves.

Now as it turns out, this particular Pirelli tread pattern (P Zero Rosso) is out of stock. He checked up with a few dealers and with the company. Says there is slim hope that we'll get it. All online portals too confirm this. So it looks like I'll have to get a full new set anyway. This changes things. If I have to go for 4 new tyres I think my best bet is getting new RFTs with better performance. Pirelli P Zero runflats seem to be available, at eye watering prices of course. Experiencing premium car tantrums first hand.

[androdev]

I think you should just buy a compatible tire and move on unless you suspect the tires themselves are defective. Why throw away 3 new tires? Hardly anyone would notice that you have a different tire, esp if it's of the same brand. Switching to full RFT by discarding 3 new tires is an overkill.

Besides RFT won't stop this type of damage. It is safe in case there is sudden loss of air through a hole but not sidewall cracks.

18" wheel low profile is the elephant in the room. I spent a lot of time researching tires and low profile tires (anything above 17" wheels) trade safety for better looks when you consider the poor quality roads we have. I still bought 19" wheels but I am sure to be going back to 17"s soon once the novelty factor wears off.

In case you want to change the full setup, you might want to consider moving to 17" wheels. You may find some take offs on OLX which would be super cheap.

[Akshay1234]

Thinking about the situation more - The pop which you heard was probably when the damage happened. Either something cut your tyre at that time, or a foreign object which was in the tyre came out at that time. After which your tyre slowly deflated, and due to the zero/low pressure the sidewall got cut and opened up.