Old Tyres

[Rupert]

While searching for something the other day, I came across a cardboard box containing three new and boxed Continental GP4 Seasons folding tyres that I vaguely remember purchasing some years ago, in fact probably about 10 years ago and since forgotten about. 

Surprisingly, they still look OK, but my questiion is, would they likely fail dramatically and suddenly?

I suppose I should just put them onto a pair of wheels, inflate and see what happens!

[hatler]

My understanding is that there will be no issues with them whatsoever.

[MartinC]

My understanding is that (outside of usage) it's UV light, heat and air pollution that kill tyres so, if stored sensibly, they should be OK.

[Rupert]

They were in a cardboard box stored in the loft.

[orienteer]

Cycle teams used to store tyres for years in darkness, so they hardened without deteriorating.

[Hot Flatus]

Julien de Vries, USPostal/Discovery chief mechanic used to age new tubular before releasing them for use in his team

[fruitcake]

Check for splitting after the tyres are installed and inflated fully. If no splitting, I reckon they'll be good to ride.

[BFC]

I had some GP4S tyres that either the compound was mixed badly or they were not properly cured in manufacture - the tread rubber was soft as shit and cut up/fell apart, the worst tyres developed a gap between the two halves of the mold along the molding line. The soft rubber was superb at picking up small flints and storing them for later.

I have not purchased any GP4S since, changed over to GP4000 then GP5000 and have had less sidewall damage/cuts with them and similar or better puncture performance.

Fit the old ones and see how they go, if they are crap it may not be down to being forgotten in the loft - a good old tyre is going to be a lot better than a bad new one. With folded tyres I have some (only Michelin Pro Race so far) that delaminated at the point of the tightest folds - sympons of this are a bulge, they always fold the tyres at the same points in the factories so the markings are visible when hanging on the shelves.

[Frank9755]

I had some old Rubino Pros in the garage.  I had bought them for PBP 2011, used them again in summer 2012 but probably not since. 

They hadn't been stored very well as there was UV around.  I fitted them on another bike in summer 2019.  I noticed that the rubber by the beads was quite brittle and a few bits flaked off. Mainly this was excess rubber beyond the bead.  I pushed on anyway, and they have been fine for 2+ years (light use).

[hatler]

My stock of Krylion Carbons are stashed away in a wooden box in the garage. I reckon I have enough to see me out and will have no qualms about using them at any indeterminate time in the future.

[salar55]

Have a stash of Schwalbe Marathon XR and  Mrathon Extreme  tyres. Was  told store in the dark and if possible in a cold place. Down to the last 4 XR spares, bought 10 many years ago whe they brought out the newer marathons. Used on the tandem, rear tyres have a hard life when touring due to the drag brake stopping speed building up in the mountains. They were selling remaining stock dirt cheap. No issues so far with the kevlar ones Julie was collecting her Alves touring bike from Charlie Ralph and was disappointed when the tyres were not available. A mouse had eaten its way through a row of tyres stored in the loft. 2 of the XR tyres were wired they went into the bin before use, slack fit as wire had broken. Only buy folders for touring now.

[giropaul]

Julien de Vries, USPostal/Discovery chief mechanic used to age new tubular before releasing them for use in his team

It was normal good practice. Not always easy if the team changes supplier, but black Sharpies can be handy.
The exception is track tubs, where a degree of “ stickiness” is important.
I’ve ridden on Clement tubs last year, that were issued in the late 1980s. They performed excellently, until one succumbed to a carpet tack.

[Pickled Onion]

Cycle teams used to store tyres for years in darkness, so they hardened without deteriorating.

Which is a property you may not want if you are cycling in the cold and wet.