Tomm Willians

I run GP5000’s on a couple of my bikes with one bike seeing much more use than the other. The tires on the more used bike have developed a noticeable flattened section on the crown which of course is most obvious when compared to the other set.
At what point do you guys/gals determine that it’s time to replace?

Iride01 

When the cords start to show or a cut or puncture is so bad that when inflated the tube makes the damaged area pooch out. Sometimes if I have ride that is important to me coming up, I might change them earlier.

I wouldn't fault you at all if you changed them when the wear indicators disappeared. Basically when ever they've gone too far for you to be comfortable. I'm willing to go pretty far, if you aren't that's okay.

AdkMtnMonster

GP5000 is worn out when the threads first make an appearance. On my bikes. Others may have different thresholds.

79pmooney

At the first of seeing cord or very thin thread, getting sick of flats or I'm not trusting them. The Vittoria Open Pave on my Mooney has paper thin, very evenly worn tread but seems otherwise OK. It's the rear tire of a fix gear so I'll erase the tread soon, but 'till then it stays on.

SoSmellyAir

After tossing the Schwalbe Lugano tires that came on my bike, I have only bought Continental tires (Ultrasport II, Ultrasport III, Grand Sport Race, Grand Prix, Grand Prix 5000). Each Continental tire I have installed has a pair of dimples about an inch apart for gauging wear. I guess I replace them when the dimples become harder to find. Yes, this is kind of a vague standard.

vane171

Does the time to replace tire(s) differ from whether you talk about 23 or 25 vs much bigger sizes? Smaller tires need to run at higher pressure and wear makes them more sensitive to blowout. And the risk is higher since if you have 23 size tires, you are more likely to ride in more sporting, riskier (read faster) fashion.

I ride my 23s well past when they develop flat in the middle, I watch for cracked rubber on sidewalls when it gets more serious (due to age I suppose since I don't ride high mileages and tires last me several years). Once I asked about my concerns with the sidewalls cracking in LBS and was told it is OK, just the top layer is separating and as long as I don't see threads...

Last tire change came about by not being able to avoid fresh pothole at high speed which resulted in four snake bites, two on each wheel and while the tires seemed OK, I was offered nice ones when I went to buy couple new tubes and decided it was time to replace both tubes and tires. Later on I patched those tubes and kept them as spares.

Geepig

I don't replace my tires when they wear as such, I move them somewhere else. So when the tires reach the wear indicators on my better bikes I shift them onto the rougher bikes, as they tend only to be used for local rides and therefore getting a puncture is less of a nuisance.

Some tires I remove and store when I obtain the bike or wheel they come on. For example, Stomil in Poland made bicycle tires until around 2005, so Stomil tires are getting rarer while the old bike scene is growing. My Stomils therefore await a better day. Saying that, if they are too rough then they get termed 'badgers' ('bald as a badger') and I have a pair of badly cracked 20" Stomil Antilopes on my gas bottle trailer and a pair of almost smooth 24" Stomil Zebras I sometimes use on my test wheels or as padding between my spare frames.

Tires, like coaster brake hubs, are a commodity.

urbanknight

When I start to get excessive flats for no apparent reason. There always seems to be a point when this starts to happen, and the wear is not always noticeable on the tire.

alo

Either
When the chords begin to show
or
When I get too many punctures
or
When the wet season begins, if they are fairly worn.

pdlamb

I think those wear dimples on some new tires are cute, but I don't worry about them.

Too many flats, which I define as a couple flats in a couple weeks (usually after going 6 months or more with no or very few flats) is my warning that the tougher outer rubber is worn down. If I miss that "indicator" I give thanks for clean roads and wait until I see threads. (Although I once rode an out of town metric with threads visible that I didn't see until the night before, far from home!)

Flat spot on the rear tire may indicate the tire's wearing down, or maybe you just need to pedal hard on a few turns to round the tire back out.

Crankycrank

I'm with the other posters by replacing them when the threads show or there's not much rubber left and I start getting more flats Whichever comes first.

andrewclaus

I experienced a first the other day, a Gatorskin tire with 5,000 miles on it. The wear indicators were gone, but it still had rubber on it. I had a replacement handy for the next time I had to fix a flat or work on the wheel at home. But it started making a whining noise at high speed, more noticeable at lower pressure. I replaced it and the whining went away. It must have been some kind of tread separation. Anyone else ever experience this?

ClydeClydeson

Tires are 'worn out' when:
1. You can see the tire's casing starting to show through the tread
2. You are getting punctures with increased frequency
3. The tire is bulging when inflated, indicating a damaged casing

Bike Gremlin

Brevity is not among my virtues.
When I consider a bicycle tyre to be worn.

FTB

Tire wear is VERY dependent on the tire itself. GP5000s can be replaced when threads are showing as others have said but really if its that long, and you are down tot the puncture belt but I doubt everyone would want to wait that long.
I run durano plus tires for training, you can ride them down to the blue puncture strip with no issues however you better replace these at this point since the tire was not designed for use like that.. and you look stupid..

Schwalbe DP also develop that flattened section (I've never seen this with GP5k actually) as OP says, some people replace them at this point but I like to get more out fo my tires than that. Unless it affects the cornering, you will be ok.

Also front tire wears at about 60% rate of rear, so you can swap them after halfway the expected replacement interval for extra use if you are really concerned

Troul 

when the tire is tired.


Excessive flats for no reason or that continuous thump thump feel.

Koyote

If you toss tires when the crown is a bit flattened, you will be throwing away a lot of good tires.

Consider this: even if the tire is brand new, when you put your weight on the bike, the tire's contact patch flattens out. You are always rolling on a flat patch.

Geepig

You can find your coat and hat by the door...

Further to what I described above, I exchange my off-road tires when things get wriggly in the wet, but I still keep them for other uses.

Troul 

suggesting an early reTIREment?

Drew Eckhardt 

I replace a tire when cords show, it gets cut, or it bulges due to broken cords.

Before switching to tires with a flat protection layer I also changed when the flat rate became unacceptable.

I always put the new tire on the front, usually moving the lightly worn front to the rear.

Contental GP4000 or GP4000SII ready for replacement:

DiabloScott

Yup. Too many little cuts, any big cuts, tread thin enough to see cords, or rubber coming off of the casing.

And this thread needs more photos:

Geepig

No, just that you should TREAD carefully....

Troul 

Wheely? Why? Wear else could such fun exist though?

woodcraft

canklecat

I've never worn out a good road bike tire. Cuts from road debris always trash the tire first. But I've gotten within a few hundred miles of wearing out a couple of lightweight tires -- Schwalbe One V-Guards -- although cuts killed those tires first. Hazards of riding rural areas near roadhouse bars and stripper clubs. Liquored up rednecks peel out of parking lots tossing glass bottles everywhere. And more recently there's new McMansion housing developments with lots of unsecured debris falling off trucks and trailers. Razor sharp chips of broken slate flooring material sliced up a couple of tires that might have lasted another few hundred miles.

Recently I had to retire a Continental Grand Prix Classic skinwall due to cuts -- I think it was metal braces from roofing or framing material scattered completely across an intersection after a collision. Happened at night and by the time I saw the debris it was too late to stop, and there was no clear path anywhere across that intersection. That tire looked like it had another 200-500 miles on it, estimating from the Conti wear dimple depth. That GP Classic has a raised center tread that gives it more wear life compared with other Conti road tires. I think that tire had more than 2,000 miles on it by then, not bad for a reasonably lightweight, smooth rolling tire.

And the puncture resistant, thick rubber tires on my hybrid and errand bike will never wear out in my lifetime. Those tires might develop age related crackling after a few years. Depends on environmental factors -- exposure to sunlight, ozone, etc. -- although my bikes are stored indoors away from premature aging conditions.