mgb

Is it the years or the miles?

I ride an 83 Schwinn Super Sport and it came with 25mm Continental Super Sport skinwall tires. I've only put a couple of thousand miles on the bike and it's always stored in the garage. I replaced the back tire only because I put a screwdriver through the sidewall trying to dismount it. I've kept the front one. Plenty of tread on it and the rubber isn't cracked or failing anywhere that I can see.

I don't need convincing to replace it -- I'm starting to worry so it'll be a new tire and tube for my peace of mind. I'm just asking, does age make a tire unsafe?

FBinNY 

Age, per se doesn't make a tire unsafe. I'm not sure that anything can make a tire unsafe since the consequences of tire failure aren't serious (for someone with halfway decent bike handling skill), but age and wear can factor in tire failure. If the tire looks OK ---no dry rotted rubber, no bulging or twisting of the tire body, adequate tread with no worn through spots, no visible cuts or scores in the wall, especially just above the rim, no sign of delamination, etc. --- then it's probably OK and you can ride it with confidence.

I'm sure that various factors can increase the odds of sudden blowouts, but these can happen even with a brand new tire which appears to me mounted perfectly, so the key to safety lies not in the tires but in your ability to handle the bike after such a failure.

johnny99

Exposure to sunlight, ozone, moisture, sea water can weaken or rot a tire. If the rubber feels sturdy and supple, it may be OK.

Shimagnolo

Rubber deteriorates with age:
https://www.tirerack.com/tires/tirete...jsp?techid=138

I had 15yo front tire blow out the sidewall while hanging on the bike rack in the garage, just a few hours after I'd done a 45mph descent on it. The tires looked fine. You couldn't pay me enough to ride a tire that old again.

Flying Merkel

I've had an old tire fail in the middle of a mountain bike ride after a small rock hit. After several years living outside, my beach cruiser's tires hardened to the point where traction was compromised. Tires are disposable. If there's a question in your m,ind, replace.

Airburst

The main issue with old tyres is, as others have said, a lack of traction and/or wear resistance. The rubber isn't really structural - all the loads on a tyre are taken by the bead and cords, so old rubber won't normally cause a blowout. Almost all modern tyres have nylon cords, which don't rot and can't really be degraded by UV light when they're inside the rubber. Some older tyres did have cotton or even silk cords, which did rot, but they're not exactly common nowadays.

FBinNY 

I don't know of any bicycle tires with nylon cords, except for some low end Panaracer tubulars (if they still make these dogs). Nylon is a poor choice for tire cords because of it's poor modulus of elasticity. Bike tires are still made of cotton, and better ones of polyester, both with better stretch to weight ratios.

HillRider

You will almost never wear out a bike front tire to the point of wearing away all of the rubber down to the casing as is common with rear tires. From strictly a wear point, a front tire will outlast a dozen rear tires. Here's an experiment: weigh a brand new front tire, then install it and ride, say 5000 miles, then reweigh it. The weight loss will be extremely small.

Front tires do age and the rubber can get brittle or crack-prone but you can't expect to literally wear one out.

FBinNY 

+1, It's virtually impossible (maybe actually impossible, but I leave the possibility open) to wear out a front tire. In well over 100k riding over 4+ decades I've never worn a front through, and that includes tens of thousands of miles on light tubulars which don't start out with much. Not only have I never worn out a front, I don't know anybody who has.

I did come close recently, with the front tire of my commuter. After maybe 15,000 miles it looked like I was going to have a first, and I kept it on even though it was so ratty that I normally would chucked it. Of course it blew apart before that last .01mm of tread wore through. Close but still no cigar.

canyoneagle

I've experienced the same longevity of front tires in a non-racing context. I tend to rotate the front to the rear, buying one tire at a time, when a rear is due.
I have worn front tires, and know people who have, but this is without exception on bikes that were ridden heavily in circuit or criterium training/racing. In this use the center tread was fine - the wear occurred on the shoulders of the tires (tubulars). Bear in mind, this was AGGRESSIVE cornering at speed, where the tire was at its adhesion limit. This was also 25 years ago when I was brave/stupid enough to ride like that

I have also worn front MTB tires, but this is not uncommon.

As for age, the sidewalls can dry out and cracks can form. If a tire looks dry, I'd say replace it.

Airburst

I stand corrected, I thought they were nylon. The Mythos XC tyres on one of my MTBs are the only ones I've ever seen that actually said anything about what they were made of, and they had "nylon" stamped on the sidewalls. Now I think about it, they wouldn't have said they had nylon cords if that was the usual thing to use...

The point still stands for polyester, and any nylon tyres you might happen to come across, but cotton tyres can most certainly rot if moisture gets in, as, I assume, will silk.

Delmarva

Considering that two new tubes and tires are not all that much money I would just go ahead and replace both since they are close to 30 years old. And please please don't use a screwdriver when mounting or removing bike tires. Either use good tire levers or just have the lbs do it.

clydeosaur

Old tires really aren't worth the headaches. Tires obviously age, start to lose flexibility and traction. The signs of cracking, seperating sidewalls, shimy / hard rubber are tell tale signs. Can you ride on an old tire? Sure. If you rely on commuting, or like to keep the chances of slipping / crashing down, wouldn't you want to replace them for those reason? Car tires have date codes on them just for these reasons. The point can be argued all day, but it simply seems like common sense.

zacster

Tires don't cost that much money that you'd want to keep riding an old one. My two exceptions are that I use an old tire on an old front wheel on my trainer bike, and that never sees the pavement, and I have a Clement Criterium Seta tubular that is mounted on my old Italian classic, and I rode it a few times but was careful to not corner or stress it.

ultraman6970

Does age make a tire unsafe? <-- would you feel comfortable riding a car with tires that are like 25 y/o and are all dried? A lot of people cant figure it out bikes but can figure it out cars.

wroomwroomoops

I think I know why: most old tires that I've seen have the most deteriorated rubber around the bead. In extreme cases, there was no rubber left (it all broke down) keeping the bead to the carcass.

wroomwroomoops

That said, I have 12 year old bicycle tires which are nearly perfect.

HillRider

Maybe that's a more accurate statement.

FBinNY 

Tires don't depend on rubber to keep the body attached to the bead. The construction consists a single sheet of bias ply fabric wrapped from beyond the center under the bead, around to the second bead and back beyond the center. That creates the reversed direction 2 ply sidewalls, with the overlap keeping it together. Rubber cement is used to keep this together, then the walls and treads are molded on.

The rubber can rot all it wants without affecting the tire's strength, though an old tire might allow water in and lead to the breakdown of the wall itself eventually.

wroomwroomoops

The safest way is, of course, just using your hands without any tools. I found that this works with most clinchers that aren't too narrow.

Shimagnolo

It was a thumb-sized hole in the sidewall. It did not occur at the bead.

wroomwroomoops

That's good to know, but I don't trust the tires where the bead isn't covered at all, one bit.

Usually those tires have the sidewalls cracked longitudinally, revealing the nylon fabric below it. I assume the same logic applies regarding the rubber vs. ply/fabric keeping the carcass together?

FBinNY 

Everyone has to make his own judgment call and decision about what he rides and how and where he rides it. I don't advise either way, I just try to keep the facts straight so those decisions might be more informed.

wroomwroomoops

Certainly, but surely one could imagine failure scenarios where a brittle rubber would be the culprit? For instance, more prone to punctures, or even exposed threads from the nylon fabric itself, causing punctures? I'm just thinking aloud, right now.

FBinNY 

IMO the dangers of tire blowouts are exaggerated. The risk of a blowout does increase as tires age or suffer nicks and cuts, but the risk is there even on a brand new tire. Tires blow out every day because of poor mounting, they blow on high speed impact with a sharp edge, like the opposite lip of a pothole, they blow when sliced by glass. In short any tire can blow out at any time for any reason.

Yet, we rarely hear of anyone injured by a blowout, not because they don't happen, but because they rarely cause crashes. As someone who has logged tens of thousands of miles on tubulars, I'd had my share of blowouts, and the only consequence is scratched rims. My commuter has also had a blowout or two, and even with those big floppy tires the only consequence is an earache.

As far as making a judgement on an old tire, body ply problems usually show up as distortion in the body long before they blow.