I have a set of tires that I am considering using for a loaded tour this month. Everything except the sidewalls looks new. The sidewalls have some slight cracking. Would these be safe to use? (The last photo is what the tire looks like on the inside).

So when you flip the tire inside out the cracking rubber sidewall doesn't start flaking off? It mustn't be, but I'd what to know what the purpose of the sidewall was in the first place. A seal to keep water from seeping into the casing or under the tread? Seeing as you'll be touring and probably don't like the idea of your wheel gaining weight as you tour, you'll want to replace them. Don't you think?

Bummer dude. Riding locally - I'd risk it - riding loaded on tour? Nah. There are better stories to be had than "blown tire in the middle of nowhere results in road rash and bent bars for the rest of the tour".

At the risk of sounding like a snob , I'm not even sure I'd be hot to ride a lot of miles on those tires when new. What are they? The tread and sidewalls look thick.

OTOH, I'm not as pessimistic about the tires asploding while you're on tour, but it may be wise to replace the front one, at least.

This is the rear tire I currently have ON the bike and am considering replacing. It's a "Michelin Protek" which has the 1mm thick reinforcement layer to protect against flats. However, it looks a bit worn as it has the sorta "squared" shape. Has no cracks or anything. Would this be a better one than the ones pictured above? (Sorry they're a bit dirty).

I wouldn't have a problem riding the Michelin tire in your last post. Sure it looks a little worn, but that's what happens with a treaded tire.

How old are the tires in the OP? In my experience they might be fine for a few years or they could blow out tomorrow. Throw them on a short distance commuter and use them up if you want, but I would not go touring on them. And I agree with ThermionicScott. I think I have those tires in blackwall. Are they cheap Kendas? If they're the tire I have they are indeed heavy slow dogs. I use them because they provide decent traction in winter without an aggressive knobby tread pattern.

Isaiahc72:

To what I can interpret in that image:
THAT be a Continental Tire. Continental tires are the least of all tires, when there be cracks.
?Town N Country?
Personally, I never got a crack, nor heard of a crack in a Continental tire.

Or am I to be wrong, in that this be another tire?

This is just normal surface checking of the rubber and has ZERO effect of the tire's performance or life expectancy.

As tires age and are exposrd to UV, ozone and road chemicals, the rubber becomes less pliable and prone to this kind of cracking, or checking. As you roll on this stiffer rubber the constant flex leads to the type of "cracks" you see.

It's a faster process with the "gum" sidewalls than with the black read rubber, but happens to everything, including car tires.

The internal structure is unaffected, and the net effect is comparable to what you might see in a stucco house, where the stucco is full of hairline cracks, but you still live there because you know it's only the stucco and not the structure.

As long as the tread is decent and there's enough that you estimate it to last through your trip the tires are fine. Of if concerned about tread wear, remove and replace the tires before the trip, and save them to finish off when you get back. Keep in mind that this is a tread wear based decision, and these surface cracks aren't a factor.

Have a great trip.

continental tyres definitely crack.

All the Contis that I have purchased & used, have not cracked.
Where are these who get such; how are the bikes/tire place/stored??
In the shade? In the sun? For how long in the sun??
Contis will survive in the sun longer than any other tire. As shade is not always to avail, for bicycle parking.
Contis also are the best traction (general asphalt-water & gripping over oil contact), for driving in the rain (as most cyclists are too sissy to do such driving).
Over-inflation of PSI of Continental has only given me better driving traction. One simply has to be a betters killed cyclist before doing so.

Every large aircraft maintenance manual I've ever worked by says that weather checking that does not extend to the body plies of the tire is ok for service.
Cheers,
David in Alaska

Me too. Those cracks wouldn't even blip my radar.

On the other hand, if those cracks are a concern for you, and they must be or you wouldn't have posted, the cost of a tire isn't much of a price to pay for peace of mind.

The tyre that cracked for me was about 2-3 years old with just under 3000km. It was stored in a dark shed at home, and when locked up while out, had about an hour of morning sun.

In my experience continental tyres last no longer in the sun than the cheapest tyres available.
As for traction, on both wet and dry roads, I have never had a problem with any tyre (except on painted lines).


This photo was taken before the tyre developed a kink in it.

There are no guarantees. They might make it, they might not. I would bring an extra tire and tube on a loaded tour anyways. I have some tires from the eighties on my spare bike and the white sidewall rubber is flaking off in some spots. I have bombed around town on them occasionally for the past few years and they have held out. The cords are still in decent shape and are not abraded. The strength in tires is in the cording. The outside rubber helps protect the cords from abrasion and the inner rubber seals them so they don't leak. If you took the cords out of the tire, you probably could not inflate them past five or ten psi before they burst (kind of like inflating a bike inner tube when it is not encased in the tire and rim assembly).