Rubber -- old vs. new vs new-old-stock
 

What's your experience with bike rubber products (tubes, tires) when it comes to quality and longevity?

Quite a vague, loaded question, I realize, so let's break it down ...

Were rubber-based bike products built better back "in the day"? (Maybe because more pure rubber was used instead of cheaper synthetics)??
New-old-stock tires/tubes .. .were they better built back "in the day" and are NOW worth acquiring?
Neglecting use and given normal indoor humidity and room-temperature, how long can one expect tires and tubes to last? (I.e. do new, modern bike rubber products have a "shelf life" or the equivalent of an "expiration date")?

Tires seem to last many years. If you have tires a few years old, they are probably not better or worse than new ones.

Old tubes may split. It is better to buy new tubes.

I'm going opposite, tires don't seem to last much past 10 years but I'm running some 25 year old tubes. Tubes are protected from the elements and sunlight by the tires.

Those in the know say that rubber only degrades with age.

Older tires may be OK, and last well if stored right,

but new ones are better than old ones. Rubber compounds are improved as well, so newer tires tend to perform better.

Sunlight and ozone (refer, furnace electric motors) degrade rubber.

I've read that rubber tires (I think this was in reference to car tires, but should be cross-applicable), do experience some degradation over time, enough that you don;t want to buy "new" car tires that are actually 10 years old, but in my experience, tires kept out of the sun seem to last many years without issues.
That being said, given the current economic realities, there's an excellent chance we'll see inflation in many things, as well as problems with production and available supply. I've always been a proponent of stocking up on things I need and am going to be buying, anyway (everything from favorite deodorants, shampoo, dental floss,razor cartridges, etc. to guitar strings, to bike chains, tires, tubes, etc.) As a rule, ain't nothing getting cheaper.
But,I try not to store tires and tubes out in the hot garage, preferring to keep them inside in a more climate controlled environment.

I've refurbished tons of old bikes over the years, many that were several decades old. Old tires are often cracked and dry rotted, and can't be used. While even though people say don't use 'em, I've not seen an issue using antique tubes as long as they show no defects and hold air.

As far as "synthetic" rubber or additives in more modern tires, I suspect it makes them last longer than "pure rubber" or whatever concoction they used in the old days.

I suspect many things will go the other way... deflation. With so many people out of work, (or making less money) and less willing to spend what dollars they do have, sellers of certain items will be forced to lower their prices.

My buddy! Maybe you can spare me a roll of TP? :D

Completely agree. Rubber compounds protected from sunshine (UV radiation), ozone, and uncontrolled temperature extremes will remain usable longer. Looking at the rest of the tire, cotton and silk carcasses degrade based on other conditions (humidity and temperature), while nylon is much longer lived and stable.

I have noticed that RV owners have cute little skirts that go over the tires to prevent the sun from degrading them. My guess is that bike tires would as well

Tyres that would require a high level of performance, such as motorcycle tyres, are significantly affected negatively by age. This affects their ability to heat up, have traction, grip the road, etc., with the consequences being you crash.

I doubt bicycle tyres have such a requirement for performance, but probably also degrade with time. If you want "the best" performance, newer is better. Even "new old stock" are going to be old, and the rubber will degrade (in the same way that motorcycle tyres would), though certainly the compounds used will be different as they are for extremely different purposes.

In summary: I wouldn't be afraid of older bicycle tyres. It's extremely unlikely you're asking so much, performance-wise, on a bicycle tyre, to make that much difference. If you think you might, if you're racing or doing something extreme, remove any doubt and use new tyres.

I hung my bike up in 2011 or so (with new tires mounted), and took it down last year. The tires aged very poorly; the tread was noticably cracked in several places. I rode on them one time and in pretty short order (5 or so miles) part of the tread detached from the casing. The tire stayed inflated and was able to complete the short ride, but put new tires on before the next ride. Bike is stored in a garage which contains a gas water heater as well as an electric freezer.

The problem is which “back in the day” are you talking about? Synthetic rubber has been used in tires since the early 1940 or even late 1930s. By the 1960s, synthetic rubber production surpassed natural rubber production. I don’t have the article but several years ago, I read that the addition of synthetic rubber to tires increased their longevity considerably. For automobiles, better synthetic rubber and radial tire construction went a long way towards increasing tire wear. Bias ply tires and natural rubber resulted in tires that wore out in only a few thousand miles while we expect 10,000s of miles out of modern automobile tires.

Modern tires still contain natural rubber in about equal proportions to synthetic. Trucks seem to have a bit more natural rubber than synthetic because latex is better at rip resistance. Here’s an interesting article on tires.

But, from my observation, modern tires do better than many older tires. Old “gum wall” tires, decayed very quickly. You don’t see too many of them around now, probably for this reason. Skinwall tires seemed to hold up a little better but they were higher quality tires than gum walls to begin with so the comparison is probably not too valid. Both gum wall and skinwall have fallen out of favor for the most part. But I’ve also noticed that modern tires tend to be more wear resistant than tires were 40 years ago. I don’t notice as many weather checked tires as quickly as I used to when I first started riding (40+ years). This could be due to formulation or to additives that do a better job of resisting UV and ozone aging.

That said, storage conditions...both on the bike and off..is going to have much more of an effect on tire longevity then construction. It’s hard to say if an old tire will be good or not without really looking at it. A tire that has been folded and placed in a bag to protect it and stored away from heat, UV and ozone will probably be in good shape, especially compared to one that hasn’t been protected or has been allowed to sit flat with the bicycle weight on it.

That said, I would say that new tires are probably better than old ones. A 40 year old tire just isn’t going to have the same chemistry as a modern one. That chemistry is going to make for a much better tire overall.

cyccommute , isn't it true that tires are black because carbon black is added during manufacture in part to add UV resistance to the rubber? It would make sense that gumwall tires deteriorated faster, since it's missing the carbon 'sunblock'.

I don't reuse old tires, but I often continue to use original tubes on old bikes. They were made of higher quality and durability, in my observation. I'm running 46 year old tubes in my Fuji Special Road Racer. I expect them to last another decade easily.

New rubber compounds are superior to old.

And the older rubber gets, the worse it performs in terms of wear, grip, and rolling resistance.

Old tires should be chucked.

I don't change tires until the tread is gone or the sidewalls tear or blow out. Tubes last forever since they are inside the casing and not exposed to ozone like the tire itself.This same topic is found on motorcycle and car forums. Bunch of wasted time. If the tire rolls, use it. If the tube holds air, use it. If racing, then a different standard applies since the tire will be pushed much harder than a casual or go faster weekend warrior type.

Yep, no doubt. I think we're seeing some of that, already, as in lowered prices on things not selling on craigslist, and current fuel prices ( $1.79 ! Woo Hoo!), to name just a couple.
It's hard to guess which way things will go on items like bike tubes and tires,but my thoughts are that we'll see temporary,isolated price drops from distressed shops looking to unload existing inventory, in a cash-strapped market. But on the other side, the relatively limited number of manufacturers may have to compensate for escalating production and raw material costs. I think things like brand new bikes, will be a luxury, and see drops in price (Lynskey has been running 25% off on everything, for a while now, biggest discount I've seen them run), while things like items needed to extend the service life of them, like tires and tubes, may go higher.
Or not. :D

Normally, I would agree with you. But in this case, along with declining aggregate demand, we may also be facing declining aggregate supply since businesses (here and abroad) are shut down. So, the net impact on price levels is indeterminate. If we suffer high unemployment and rising inflation, our economy could look like the late '70s -- albeit on a much worse scale.

Newer tires are made better than old ones in regards to flat resistance, cut resistance, rolling resistance and they get longer miles out of them then they use to.

I don't usually keep tires for more than 6 years, they are usually worn out by then, but for some reason I kept two pairs of tires from the mid 80's; the one set is made by Silver Star, but I'm not sure if that was the real manufacture of just some brand they slapped on the tire, these tires are in excellent condition with no cracking even starting, I could ride on those today without a problem; the other set is so badly cracked I can no longer make out the branding label and I don't remember either, that set I wouldn't dare ride on. Both sets were stored exactly the same, so why did one set crack up and the other is fine? I don't know unless there was something different in the compositions of the two sets, maybe one set was more on the nature side and the other more on the synthetic side?.

Tires can be stored for a long time, and I think modern tires should be able to store longer than the older ones could. I have a set of 2 year old tires, not that old, but I have them in a ziplock bag.

It’s primarily added as a filler and stabilizer. It was originally added so that less rubber...natural and synthetic...could be used. But it was found to significantly increases the durability of the tire. Tires used to be lightly colored from use of most natural rubber but they wore very quickly. The light colored tires used on bikes back in the 90s had more latex which gave a good sticky tire for mountain biking but if you used them, you could burn through a set very quickly. Once carbon black was added to tires, people noticed that they lasted longer.

The thoughts I’ve seen around on the way the carbon black works is that it helps move heat away from the tread. It may also help with UV resistance but that is a secondary benefit.

Some people are talking about tires much older than others.

I have 10 to 15 year old tires which have been kept where they are not exposed to sunlight, and are still good. Some tubes which are 15 or 20 years old, kept in a shed, are already splitting.

I have mentioned before, I picked up this bike. The tires and tubes are probably over 20 years old. I just pumped them up and rode the bike. But then the bike seems to have always been in a shed. It has no rust or corrosion.

https://cimg4.ibsrv.net/gimg/bikefor...6fd4370c66.png

With tires you can often tell by looking at them, whether they are still in good condition, or they have deteriorated.

Some people say they use old tubes, and as they say, tubes not exposed to sunlight will last longer than tubes exposed to sunlight. I sometimes pump tubes up, before fitting them in tires, to see if they hold air. I find it annoying, if after fitting a tire and tube, it leaks, so you have to take it off a do it over. So I tend to only use good or newer tubes.

I also use those mountain bike tubes which are thickened to reduce the likelihood of punctures. I don't use old thin tubes.

Generally I wear out the tread of a tire long before the rubber deteriorates. Tubes - I use them as long as the valves and patches hold. I have at least one in use that's over 20 years old. One of the reasons for keeping them is the low availability of tubes with short Presta valves. I really hate the look of an inch and a half of valve stem sticking out of the rim.

Also, I do have some silk sew-ups that are over 35 years old and holding up fine. They are on wheels for a vintage bike and not used very much.

Couple of things I should've added to the OP...
Clearly, rubber (or ingredients) quality and tire/tube quality are not mutually exclusive. E.g., a manuf. can mess up a tire/tube model even if they used the highest quality-ingredients (and vice versa). Poor engineering, quality control, improper testing, etc.

In another thread, I posted on my 10-year-old 700x28 Kenda Kwest tires. The Fuji Absolute 2.0 hybrid commuting bike, which I bought new in 2010, came stock with them. I probably have only 300 miles on them/bike ... the bike is never ridden hard, rarely over 12mph, always on well-paved roads or bike paths, and never carrying over 140 lbs weight (me + pack). I always use max pressure (80psi) . The bike is always stored inside at room temp., in a dark area.
The Kwest's are not a bottom-end tire ($20/ea. today).
Given all that, I was surprised to recently discover that for the REAR tire, a moderate amount sidewall cracking, and one 1mmx10mm split on the tread. The split had led to two flats.
The tread on BOTH tires seem in similar shape, otherwise. And both innertubes are "like new", other that two those tire-based flats (both literally within two consecutive rides, right thru the prev. patch for the 2nd time. Yes, I did attempt to repair the tire, too) .
Again, the tires/bike were not used that much and gently used at that.
"Bad rubber????"

$20 each new is an entry level tire. It stinks to replace a tire you barely used, but spending just a little more on your tires can transform the ride.

10 year old tire no worries. 20 year old tire needs to be replaced. 30 year old tire - fuh get a bow it!!!