Topic: Tire Question - 7years mounted,full pressure, off bike, Safe to ride on?

[MCRider]

An excerpt from the following article:
http://goliath.ecnext.com/coms2/gi_0199-4187033/The-invisible-danger-of-aging.html

which is appears to be an objective study (non-industry or media) with footnotes, etc. You must register to get the full article with source backup.

" The internal oxidative degradation caused by air permeation occurs over time, regardless of whether the tire is used. Current studies suggest that in-use tires age no more than those stored as spares on the same vehicle. In other words, age degradation occurs regardless of the mechanical fatigue that a tire undergoes. (6) "


Oops, I see that at the end the author is identified as a lawyer. All bets are off.   

[Inigo Montoya]

Here is a quick little read. It does support the 7 year or so thing(for the most part) but also goes into other details.
http://www.canyonchasers.net/shop/generic/tires.php

[Rampage1967]

Is a couple hundred dollars for tires worth risking your life for??
I had 8 year old tires on my 4x4 truck cause me major safety problems due to separated belts.
Just think about the results of a tire failure at a critical moment on a bike and the results.

I know you guys will flame me for this statement, but I trust a brand new Cheng Shin much more than an old Bridgestone Battle Ax (well know high quality tire example).  I threw away a set of new looking Battle Axs that were dated 1994 the other day in fact.

[Grnrngr]

This is a great thread, no serious flaming and lots of info for thought. Wish I'd seen the trashcan you threw them in, I'd have paid you for them. I certainly wouldn't ever recommend anyone put anything unsafe on their vehicle, and perhaps the judgement calls are best left to those with the experience to make an informed decision. I tend to think some of the age thing is industry hype, tires have been sitting in warehouses as described in the article, since tires have been made, and just seems odd to me that people would so recently become concerned about tire age. But there can be no denying the effects of oxidation, and I have run across some pretty stiff old tires. But I'm talking at least 15yrs old, probably more. I've had lots of experience running junk tires and recaps on lots of different kinds of vehicles and have learned thru experience how to read a tire. Some of them were hard lessons but they were all due to lack of tread rather than failure due to age. Experience has also taught me that a new tire will need to be changed a lot less frequently than a tire with only 10% tread left, so I don't run junk tires anymore and I don't think you can get recaps anywhere now. I have run a lot of old tires that had significant tread left and ran the tread off without any problems, I've also run newer tires (on my truck) that have had tread seperation issues, which I think are more a manufacturing problem, and probably the more likely reason for the industry position on "age". Bridgestone..aren't they the ones that had the SUV/LT (new) tire recall about 10/12 yrs back? I'm still running the Michelins Costco gave me in exchange. Great tires, no age issue. There is definitely an advantage to buying tires with a warranty. And ultimately, their can be no denying that the newer the tire is, and the more tread it has on it, the safer it will be..excluding manufacturer's defects of course...

[Inigo Montoya]

Actually I think it was firestone that had the separation issues.

[MCRider]

Actually I think it was firestone that had the separation issues.

Bridgestone owns Firestone so they were both in the litigation.

Addressing another point made by grnrngr: the age thing was suppressed not promoted by US tire industry as there was and is a lot of old inventory that should be destroyed to the detriment of the industry.  The US is late to the table about the knowledge of the danger as Europe and others have made the warnings for decades. Its largely independent consumer advocacy groups that are educating the US, and the tire industry is grudgingly giving in.

That's how I read it.

[ekpent]

Not pertinent to our discussion per say but in an article in the current Cycle World about racer-flat tracker Slidin' Al Gunter old hard tires were the thing. He even learned how to cook them in a pizza oven,tasty, when the old Pirellis were gone

[Inigo Montoya]

The article I posted said some also threw the tires on roofs for a while in the sun to harden them.

I never used firestone so I never looked into it so I was unaware that bridgestone owned firestone.

[Laminar]

The difference between two well-reviewed brand new sets of street tires can be huge, depending on the particular tire design and rubber compound.

Yes and everything you stated is on the track. A track is not a street.You just do not encounter all the variables on a track that you do on a street.

Yeah, on tracks you have potholes, wet leaves, sand patches, curbs, manhole covers, kids playing, gravel, blind intersections, oil slicks, SUVs, etc.

[Inigo Montoya]

So you are saying the street is your track?

[Laminar]

So you are saying the street is your track?

Are you saying that all of those varied conditions appear on the street??

[Inigo Montoya]

Yes I am. But i am sure you knew that.

[Laminar]

Now explain to me the variables you see on the track that you don't see on the street.

[Grnrngr]

heh...just saw Worlds Fastest Indian the other night, seems ol Burt Monroe found old tires, then CUT THE REMAINING TREAD OFF, and "guaranteed" them for 200+mph. but again,thats a guy who knew what he was doing making his own decision, and not recommended for the general public. The issues I had with my truck tires I doubt would ever be encountered on a bike simply because a truck tire carries considerably more weight over a wider surface area. I think once mine got below a certain tread depth, but not entirely gone, the rubber could no longer control the belted core, which distorted and destroyed itself. I've gone over the bars a few times because of front tire blowouts on my bicycle and didn't enjoy it much, got a lot of respect for a good front tire, dont really think about the back much. It's been my good fortune to have never had a blowout on a motorcycle, but have had the occasional flat and was able to get off the road before it was totally deflated  But...that was back in the day with a tubed tire. A tubeless tire just doesn't have that extra layer of rubber and so i would think, is less "safe". So in a similar vein...if you buy a brand new tire made yesterday, and you pick up a nail today, do you get it repaired or buy another new one?

[Inigo Montoya]

Now explain to me the variables you see on the track that you don't see on the street.

I would but I dont care to.

[Laminar]

Now explain to me the variables you see on the track that you don't see on the street.

I would but I dont care to.

Adorable.

[Inigo Montoya]

Yes I know. You should take notes.

[Rosinante]

........got a lot of respect for a good front tire, dont really think about the back much. .......

We share that same healthy respect for good tires.  Front tires are more critical, as you say.  Rear tires might also be just as critical.  On both cars and motorcycles, rear tires pick up screws and nails more than front tires do.  As the saying goes, "The front tire kicks it up, and the rear tire picks it up."