Tires: how old is too old?

I had a few questions and wanted to bring back up this tire thread question.

I currently have some dry rot on my left main and nose gear tires. Here’s my question with dry rot:

If i’m replacing the dry rot tire do I need to buy the tire and the tube or just the tire?

is there anything i can do to help prevent dry rot? The aircraft sits outside in southern nevada until I can get a shade hangar in a year. Should I buy wheel covers?
 
Replace the tubes also. And buy a spare tube to carry in the back. Also might need that spare if you pinch a tube installing them. Or save the old tubes to carry as spares to use in a pinch.
 
texasclouds said:
Replace the tubes also. And buy a spare tube to carry in the back. Also might need that spare if you pinch a tube installing them. Or save the old tubes to carry as spares to use in a pinch.
Click to expand...
I have a tube and tire sitting in my garage from my first annual. The tread is a bit worn but I've kept it as a backup. Do you usually carry a spare on XC incase you need it? My wife brings a lot of bags, I'm not sure I'd have room.
 
So here this guy with a Sling High Wing who blew a tire in the middle of no where. He didn't know he had a tubeless tire so he couldn't fix it. Claims if it wasn't tubeless he could have repaired it and be on his way since all he had was a repair kit for a tub tire. Not sure how he repaired the tire.

 
I keep a spare nose and spare main tube in my kit. If I’m set back due to a flat, I don’t want resource availability issues to prolong the problem.
 
NoHeat said:
If a tire's tread is still good, and there are no punctures, cracking, or other obvious aging of rubber, should it nevertheless be replaced eventually, based just on time?
Click to expand...
10 years is about when I would think about replacing them in most cases. Cracks on the sides would be a disqualifier imo.

When I started to fly my late friends 172, all 3 tires had cracking showing on the sides and in the tread. I pointed it out to him and he blurts out the tires had low hours on them! lol He was right but he only flew the plane about 9 hrs in 10 years. Tread was like new but the sidewalls showed cracks. I replaced them and the tubes. Small cost verses what could happen.
Last year I mounted up Dresser monster retreads on my 172. 11/16" deep tread which makes them a little taller and heavier. First I was concerned about how heavy they were compared to my old worn out tires. Turns out...the heavier weight was worth it.
I really like them, runs smooth and handles bumps on turf better then my old tires.
IMG_1965.JPG
 
Last edited:
jkgoblue said:
So here this guy with a Sling High Wing who blew a tire in the middle of no where. He didn't know he had a tubeless tire so he couldn't fix it. Claims if it wasn't tubeless he could have repaired it and be on his way since all he had was a repair kit for a tub tire. Not sure how he repaired the tire.

Click to expand...

Nearly twenty seven minutes to show me a flat tire ... nah, TLDW
 
"Dry rot" requires some moisture to happen. It usually doesn't apply to rubber. Organic materials like wood suffer dry rot, and it's normally a fungal thing.

Aircraft tires sitting outside, in the sun, suffer ozone cracking and UV damage that can look like dry rot in wood.

https://en.wikipedia.org/wiki/Ozone_cracking
 
Gary Ward said:
10 years is about when I would think about replacing them in most cases. Dry rot on the sides would be a disqualifier imo.

When I started to fly my late friends 172, all 3 tires had dry rot showing on the sides and in the tread I pointed it out to him and he blurts out the tires had low hours on them! lol He was right but he only flew the plane about 9 hrs in 10 years. Tread was like new but the sidewalls showed rot. I replaced them and the tubes. Small cost verses what could happen.
Last year I mounted up Dresser monster retreads on my 172. 11/16" deep tread which makes them a little taller and heavier. First I was concerned about how heavy they were compared to my old worn out tires. Turns out...the heavier weight was worth it.
I really like them, runs smooth and handles bumps on turf better then my old tires.
IMG_1965.JPG
Click to expand...
That picture made me think "backcountry airplanes should have dualies".:)
 
When in doubt, change out. A tire problem in the road can mess things up. A blowout on landing, another hazard.

When I bought my current plane, the front tire was cracked a good bit. I had it replaced fairly soon.
 
Dan Thomas said:
"Dry rot" requires some moisture to happen. It usually doesn't apply to rubber. Organic materials like wood suffer dry rot, and it's normally a fungal thing.

Aircraft tires sitting outside, in the sun, suffer ozone cracking and UV damage that can look like dry rot in wood.

https://en.wikipedia.org/wiki/Ozone_cracking
Click to expand...

While you are correct that it is not really rot, that is what it is called in tires.
 
replace them if they are over 7 years old. I have a classic corvette that spends it life in side. the tires were the ones on it when i bought it 8 years a ago. they looked great, no checking, no cracking, even had good tread. until the day i was backing out and the right rear tread peeled off the entire tire. good thing was not on the highway. you cannot see inside the casing, tire are cheap, replace them if they are that old.
 
Cessnas of the mid ‘60’s came with tubeless tires.

These were of a type that were inflated with a “ football pin” through the sidewall.

Of course they eventually leaked. Cessna had a conversion fix to install tubes.

Many folks decided to just stick in a tube with no marking of the unused port.

Invariably someone would try to fill the tire with the pin, right through the tube!
 
I have had zero flats in 20 years of flying, I attribute it to

#1 keeping them properly inflated.
#2 new tubes when the tires are worn out.
#3 Luck, I haven't run over any sheet metal / drywall screws, unlike my cars.

All of them are stored inside and tread wear takes them out before age.
 
Last edited:
Pinecone said:
While you are correct that it is not really rot, that is what it is called in tires.
Click to expand...
I really wish we could just use the correct terminology. We'd all learn more and we wouldn't be teaching erroneous stuff to new pilots. The training is bad enough as it is.

Tire "dry rot" is a term carried over from automobile circles, and the car guys are not known for accuracy. Some of them are known for preaching that "torque" is the only number that matters when talking about engine power. One can hardly imagine worse ignorance that that.
 
bnt83 said:
I have had zero flats in 20 years of flying, I attribute it to

#1 keeping them properly inflated.
#2 new tubes when the tires are worn out.
#3 Luck, I haven't run over any sheet metal / drywall screws, unlike my cars.

All of them are stored inside and tread wear takes them out before age.
Click to expand...

If it was me, I'd be jinxed if I said that^^^^^^^^^^^^^^^^^lol
I put 3 new tires and tubes on my 172 in 2018.
The front one went flat at my home airport right before I was going to take off when it was 1-2 years old. It was a little out of round and kinda beat up from taxing from the runway to my hangar with it flat. So I put a new one on with a new tube. I went from a airhawk to a goodyear filghtII for the front.
The air hawks on the mains held up good for 4 years with no flats. They had approx 2500 landings and take offs on them. I could have flipped them on the rim to get more time out of them but didn't. I felt it was time to replace them from tread wear not time. Do you think I changed them too soon? As I see some schools wait until cord is showing to replace them.
IMG_1893.JPG
 
Gary Ward said:
I felt it was time to replace them from tread wear not time. Do you think I changed them too soon? As I see some schools wait until cord is showing to replace them.
Click to expand...

Those tires are shot. Schools that run them to the cords are just asking for an accident or a really inconvenient and expensive AOG situation somewhere. A four-ply rated tire actually has only two plies (layers) of cord, since they're now nylon or polyester instead of the linen or cotton or rayon like they were many years ago, and those two layers represent one short skid from a blowout, maybe even on touchdown. Just find a tire like that and stick one hand inside and the other outside and feel just how thin and flexible it is. It's shocking.
 
Gary Ward said:
Do you think I changed them too soon? As I see some schools wait until cord is showing to replace them.
Click to expand...

I would have changed them a little sooner but most likely because I was bored and it seemed like a good fit with my freetime.

You did fine IMHO.
 
Dan Thomas said:
Those tires are shot. Schools that run them to the cords are just asking for an accident or a really inconvenient and expensive AOG situation somewhere. A four-ply rated tire actually has only two plies (layers) of cord, since they're now nylon or polyester instead of the linen or cotton or rayon like they were many years ago, and those two layers represent one short skid from a blowout, maybe even on touchdown. Just find a tire like that and stick one hand inside and the other outside and feel just how thin and flexible it is. It's shocking.
Click to expand...
Thanks for your opinion, makes me feel better.
I noticed how thin they were. What I really noticed was how nice the new thicker tires performed.
 
So if I'm parked outside is it worth it to buy tire covers to prevent the sun/UV damage? It used to be hangared but the dry rot showed up after parking it outside for 8 months in nevada.
 
Therookguy said:
So if I'm parked outside is it worth it to buy tire covers to prevent the sun/UV damage? It used to be hangared but the dry rot showed up after parking it outside for 8 months in nevada.
Click to expand...
I would cover them, surely can’t hurt and will help extend there life.
 
Last edited:
Dan Thomas said:
I really wish we could just use the correct terminology. We'd all learn more and we wouldn't be teaching erroneous stuff to new pilots. The training is bad enough as it is.

Tire "dry rot" is a term carried over from automobile circles, and the car guys are not known for accuracy. Some of them are known for preaching that "torque" is the only number that matters when talking about engine power. One can hardly imagine worse ignorance that that.
Click to expand...

Actually, there is no such thing as dry rot in wood. Wood rots due to fungal growth, and fungi need moisture, hence DRY means no moisture, therefore no rot. It may not be wet NOW, but it was wet at some point.

But every field of human endeavor has its own language, using terms in ways that are different from other endeavors. Take Stall for example. :D
 
Pinecone said:
Actually, there is no such thing as dry rot in wood. Wood rots due to fungal growth, and fungi need moisture, hence DRY means no moisture, therefore no rot. It may not be wet NOW, but it was wet at some point.

But every field of human endeavor has its own language, using terms in ways that are different from other endeavors. Take Stall for example. :D
Click to expand...
Way back in post #51 I said this:

Dan Thomas said:
"Dry rot" requires some moisture to happen. It usually doesn't apply to rubber. Organic materials like wood suffer dry rot, and it's normally a fungal thing.
Click to expand...
 
Tend to replace car and aircraft tires early and often. They lose their stick even if not yet checked or visibly damaged after a few years. The taildragger mains get replaced often if flown on pavement. The whole plane is resting on those tires - seems smart to make sure to keep them fresh.
 
Please see attached maintenance guide from Good Year. Pages 26 to 36 describe with pictures all the conditions requiring replacement, beyond just cracks and punctures. If none of these conditions apply to your tires, I would continue using them.
 

Attachments

  • Good Year Aviation Tire Care.pdf
    2.1 MB · Views: 7
Pinecone said:
Actually, there is no such thing as dry rot in wood. Wood rots due to fungal growth, and fungi need moisture, hence DRY means no moisture, therefore no rot. It may not be wet NOW, but it was wet at some point.

But every field of human endeavor has its own language, using terms in ways that are different from other endeavors. Take Stall for example. :D
Click to expand...
Dry rot needs moisture to happen, and atmospheric moisture is enough if the air is humid enough. It doesn't have to be wet.

From Wiki:

The term dry rot, or true dry rot, refers to the decay of timbers from only certain species of fungi that are thought to provide their own source of moisture and nutrients to cause decay in otherwise relatively dry timber. However, there has been no published experimental evidence to support the phenomenon.[4] In modern texts, the term 'dry rot' is used in reference to damage inflicted by either: Serpula lacrymans (formerly Merulius lacrymans) predominantly in the United Kingdom and northern Europe; and/or Meruliporia incrassata (which has a number of synonyms, including Poria incrassata and Serpula incrassata) in North America. Both species of fungi cause brown rot decay, preferentially removing cellulose and hemicellulose from the timber leaving a brittle matrix of modified lignin.....

..........The term dry rot is somewhat misleading, as both species of fungi Serpula lacrymans and Meruliporia incrassata require an elevated moisture content to initiate an attack on timber (28–30%). Once established, the fungi can remain active in timber with a moisture content of more than 20%. At relative humidities below 86 percent, growth of Serpula lacrymans is inhibited, but it can stay dormant at relative humidities down to 76 percent.[5] These relative humidities correspond to equilibrium moisture contents of wood of 19 and 15 percent, respectively. It is to be remembered that most forms of rot cannot be stopped.

 
Didn't a couple of us say pretty much that already? :D
 
Aviation tires go from the very worst (TON KEEP) to the very best so the "on condition" inspection seems to make the most sense. On motorhomes, whether in use on the highways or not, seven years is considered to be about the time to be thinking of new ones. So they say.
 
I just got new tires on my 2014 CB-1100 motorcycle. I ‘ment’ to get them last year. The tires that came off were original, lightly used motorcycle at 6500 miles. The front had some ‘cupping’, rear medium worn.

I know a local auto shop told me they don’t like to mount tires over 7 years old.

Checking pressure periodically is a good idea with any tire.
 
I replaced my tires a few months ago. I kept the old tires and tubes. The tires were pretty well cracked, but far from "seeing the air" in them.
They'll do in a pinch. Back in the day, if we replaced tire and tube every time we had a flat when spraying mesquite, we'd go broke. ;)
I kept a pump, and patch kit on hand at all times. It was not unheard of to come time to replace tires due to being worn out, and find 8 or 10 patches on the tubes. Yep it would get new tubes at that time. :D
 
You must log in or register to reply here.
Back
Top