EGreen

I am clueless when it come to deciding whether or not it's time to put on a new set. Usually it's an arbitrary decision or based on it seeming to have been awhile. I don't keep track of my miles (my daily base ride is about 25 Miles - but I often do far more) and I don't know what to look for aside from an obvious tear or gaping hole.

When I do change them, I am reluctant to throw them out thinking they might have more miles in them, as a result of have a closet packed, ready to explode, with used tires.

Anyone have a a clue about determining when tires need to be trashed?

botto 

when you can see the casing, when they're squared off, when you start flatting frequently, when they're cut...

rodrigaj

When I see squaring.

One of the selling points for Conti GP 4000 tires is that they have depth markers imbedded in the rubber. When they are gone, it's time to replace. Why every manufacturer doesn't do this is beyond me.

mihlbach

Basically when it starts flatting frequently it should be replaced. The amount of wear the tire will withstand until this starts happining will vary. I've replaced tires with very little wear because they started getting flats all the time and others have gone well past getting squared off without ever flatting. My rule of thumb is, as long as the tire remains reliable, keep using it.

2Tired2Shift

https://www.ocfoundation.org/1005/m150a_002.htm

asgelle

I don't understand replace a tire when it begins to show squaring. Rear tires begin squaring on the first ride and can last thousands of miles after some flattening is visible.

I also don't see the point of wear indicators. Replace a tire when the cords start to show. That's the only wear indicator anyone needs. If you're going on a long trip and are worried about a tire wearing out while you're away, put on new tires for the trip and use the old ones up when you get back.

Camilo

I agree with almost all of this, but wouldn't normally wait until a worn tire starts flatting "frequently" to replace it. To me the whole idea is to replace it before it starts flatting frequently because I hate repairing flats on the road.

On the other hand, I probably waste a lot of rubber changing prematurely, but it's worth a little wasted money to avoid unnecessary flats.

Winter76

When you can see the wires/threads it's time to replace them.

Retro Grouch 

I can't remember the last time that I actually wore a tire out. I don't get very many flats, but a high percentage of the flats that I get result in tearing the tire caseing.

zacster

There isn't one single indicator, all the things mentioned come into play. The last time I changed a tire was when I got 2 flats on one ride. It also had a few cuts and looked worn but not obviously worn out. That was enough. The tire (GP4000) I bought that day over a year ago is still on my bike and I haven't had a flat since, but I know I'm due.

operator

That's it? You may have changed it out prematurely. Unless you know something you're not telling us. 2 flats in one ride hardly means your tire is shot.

daredevil

Same here. Usually some kind of puncture or hole in the side wall is what does mine in.

slimvela

Two flats on one ride...

Had to change a tire after one flat; penetrated/cut the sidewall after only 19miles into the ride! Then again, the other half of that set is currently rolling towards 1K miles.

Machka 

-- When I see threads

-- When I get my third flat on that tire

-- When there's an obvious hole

-- When I reach about 4000 kms

Whichever comes first.

USAZorro

After about 20 minutes at 375. Be sure to use foil lining in a non-stick pan, and use a self-contained air supply when removing.

The rear wears out 2-3 times faster than the front, so I pay no regard whatsoever to overall mileage/kilometerage (is there such a word?). Otherwise, I like Machka's guidelines.

ken cummings

Don't throw them out either. My favorite LBS moved to a newer building and offered a water bottle for each old tire turned in. I took the tandem down there with 7 old tires and rode home with 5 new bottles. Specialized (plug) sponsored the give-away as the shop carries their line. Now if they only had some 700x28slicks with thick rubber.

zacster

Like I said, it had some cuts, one was large, and was looking a bit worn and squared off, if not totally worn out. I figured it was only going to get worse so I tossed it. There was a shop on the way home that had exactly what I wanted too (all black GP4000).

Back in my poor old days I used to use the tires until the threads showed. I also got a lot of flats. It just isn't worth the aggravation anymore to me.

John Wilke

When the cords are showing in more than 6 places.

When the yellow sidewalls show where the tread used to be.