Tire blowout - Ecopia EP422 on leaf 2011

Hi,
This morning, when I was taking kids to school one of my Ecopia Ep422 exploded. I was in the car pool, doing 80. There was bank, tire pressure light came on, and plop-plop-plop sound and slowing down. I was surprised, that I didn't have any loss of control, I gently braked and stopped.
By the time I stopped, the rim has already cut a sidewalls in a few spots.(After my wife came with another car to take over the kids and I was waiting for AAA truck) I walked back along the shoulder and couldn't find anything on the freeway that would cause the puncture.
My tires have 22000 miles on them, (as the car does) and have about 30-40% of thread left. I got the car towed to famous local used tire store (Miramar, San Diego), the service guy couldn't find any holes on the thread and he was pointing to the big almost square or round hole beside sidewall material as a point where tire failed.

Is there any history of this specific tire failure? Has anybody have similar experience? The key point is: is it safe to drive these 3 year old tires ?
I keep them at 38-40psi as dealer service mechanic recommended. (Specification on the tire says "max:45psi"). They were also helium filled.



Thanks,

imaric said:

They were also helium filled.

Click to expand...

:shock: :shock:

Did you ever lift off on big bumps??

The route that I drive every day, for last 5 years, doesn't have any bumps or potholes. Any, yes I always try to avoid manholes and reflective lane markers (the high ones). I try to be gentle to this car, to last as long as possible. But if i have to hurry, I drive it fast, as long as it is safe. Nothing crazy.

The factory uses Nitrogen in these tires. They reason that Nitrogen is less volatile to expansion as a result of temperature variation. Helium would require an explanation.

The Ecopias, particularly on the earlier cars, did have a history of random blowouts and failures for no particular... They are anecdotally fragile. That is one of the reasons why I went to the Michelin MXV4s early on... BTW, most run them at 40-44 pounds, often the former...

Not to excuse the tire failure, but I wouldn't do 80MPH with 30% tread left, and my kids in the car...anyway, what was the inflation pressure? Ecopias seem much more flexible (TOO flexible) at 34psi than at 40.

RePo said:

The factory uses Nitrogen in these tires. They reason that Nitrogen is less volatile to expansion as a result of temperature variation. Helium would require an explanation.

Click to expand...

Iirc, at one point the US indoor cycling team was pressurizing their tires with Helium, for some miniscule weight savings. I don't think it would be a good choice for passenger car tires. I think it would diffuse rapidly through the rubber, leading to quick pressure loss. Unless you carried a Helium tank around you'd end up with plain air fill pretty quickly.

imaric said:

... My tires have 22000 miles on them, (as the car does) and have about 30-40% of thread left.
...
The key point is: is it safe to drive these 3 year old tires ?
I keep them at 38-40psi as dealer service mechanic recommended.
...

Click to expand...

Probably not safe to keep driving on those tires.

First, the Nissan and dealer tire pressure recommendation is way too low.
Weight loading on the tire is way too high for that pressure.

A few people did get near 90,000 miles on them.
But very few.
Once I learned on MNL that they needed more like 44 psig, I have run that since the first year.
But the edges are in poor shape on mine at 23,000 miles.

Buy new tires :shock:

40psi worked fine for me - I just didn't like the handling, and worried about the reliability with no spare. (In fact I added a spare.) My four OEM Ecopias have 5k miles on them, and are currently for sale. If you live in or near Upstate NY and want a good set, PM me.

OK, I filled my kids' balloons with helium before writing the post I have nitrogen in the tires. 40PSI.

As for 30% thread, what does it have to do with sidewall strength and speed? :?: I thought that rubber cracks and aging, sun exposure, plus beatings like potholes and curbs can weaken the tires.

For last 27 years, I'm making around 15k miles annually, (plus I've done some racing) I always used the tires all the way to the min thread marker. We don't have constant rain here in San Diego, nor snow or ice. if it rains, I slow down (contrary to many here who speed up to get home sooner, i.e. to drive in the rain as short as possible). Some tires were OEM, some were Evans tire cheaper brands. No fancy cars, Toyotas. Hondas, Subarus, some SUV's. Had a couple of punctures (who doesn't? specially when your neighbors are doing home improvements ;-) ), once on the edge of the sidewall (beyond repair) but never a blowout. Once I didn't see a foot deep pothole and damaged the rim, but GoodYear tire didn't blow nor deflate.