vol

I just found something strange on the tires of my new bike (ridden only few times): on each tire, there are two holes 12 cm apart, slightly off center on opposite sides of the midline. I don't know how deep the holes are, but obviously the tubes have not been punctured, they are very full after yesterday's ride. At first I thought the rear tire ran over some protruding objects like a nail, but then I found the front tire has exactly the same two holes, in the same positions! See pictures below--the holes are circled.

It seems to be extremely unlikely they were caused by both wheels running over the same object while keeping such a straight line. So how could the holes have got there? They cannot be from the factory?

AnkleWork

Can't tell much from blurry pix; they look like fuzzy manufacturing artifacts.

Let the game of twenty questions begin: Do the holes penetrate to through to the inside? Make and model of tire?

mileslong

They look like wear indicators.....when you can't see the holes anymore, it's time for new tires.

Shimagnolo

This is a photo of a Continental GP4000 with some miles of use on it.
When the wear indicators vanish, you have maybe 200 miles until the cords show.

vol

Oh, thanks! Never knew there was such a thing as wear indicator on the tire! That must be it. The tires are Specialized Espoir Sport Reflect, 60TPI, double BlackBelt protection, 700x30.

So do all/most tires have them? Always two on each tire?

Doesn't the indicator hole make that part of the tire vulnerable?

Shimagnolo

There is no firm rule about wear indicators.
Hell, Continental puts them on GP4000's but not Gatorskins.

johnny99

Softer rubber wears more quickly, so the indicators are more useful. Gatorskins are usually fine until the rubber is thin enough that you can see the cords through the rubber.

vol

Here I found the Specialized document about this. In my case it's 120mm instead of 110mm, and no arrow or T.W.I. marking.

base2 

So far as I know Gatorskin Hardshells, at least the ones I have anyway have those exact wear indicators. About an inch apart though. I'd venture the regular Gators have them too, but I'd have to look.

What I think is funny isI don't recall the racing tires I've come across as ever having wear indicators. It's probably about right though, All the racing tires I've tried all end torn to shreds long before the tread wears out anyway.

Shimagnolo

I ran Gatorskins on one of my bikes for 10 years, and never had one with wear indicators.
(Switched to Schwalbe One's last year).

CliffordK

Continental also puts a mark on the sidewall indicating where to look for the wear indicators.

I will say that I pay attention to tire condition, and not those little holes.

I had a pair of Origin8 Elimin8ers that had a green tread, and black under the tread. I put over 1000 miles on the tires after seeing black,without getting down to the threads.

DiabloScott

This is why I like tires with a fine file tread.

When treadless tires first came out, there was some concern about knowing when they were worn out.

base2 

Just went and looked at the 32's I have on my tandem. Regular Gatorskin's have'em too. My tandem tires are only about a year old. Maybe they decided it was a good idea after all these years? In 1997-98 I ran 26x1.5 Gator gum-wall slicks on my mountain bike and there was no such thing as wear indicators I was aware of. To whoever came up with them: It's a good idea. Cords=no good back then!

canklecat

Continental says they've been phasing in the tire wear indicator dimples on road racing tires, including Gators, but there are still many tires in stock around the world that don't have the wear indicators. They don't seem to think it's a big deal, just an added bonus for folks who may not know how to estimate wear on tires that don't have tread to aid with estimating wear.

CliffordK

I have to wonder if those wear marks are conservative, which also means selling more tires.

canklecat

I'd worry more about tiny shards of glass, grass burrs and wires from steel belted radials sneaking through the tread thinned by those wear indicators (which has already happened with the sipes in my all purpose hybrid bike tires). If I spent that much money on road bike and racing tires with minimal tread I'd rather learn to inspect tires properly.

vol

^ The divots on my tires look like very deep holes, I can't see the bottom, really like a nail or thick needle puncture. To me this is almost like taking daily X-ray in order to find the tumor in time.

CliffordK

For the most part, I ignore those holes But, so far I don't think they've picked up a single piece of glass, or stone, or wire or anything else. They aren't that deep on the gatorskins and gator hardshells. Perhaps other models have deeper holes.

canklecat

Yep, the wear indicator holes look pretty deep on Conti's website too. I'd rather see something like a color band that begins to show as the tread wears. Anything but pre-drilled holes for sharp pokey stuff to sneak through.

Jobax

Straight out of the factory.

Shimagnolo

vol

It's not a toomah; it's a hole.

Rowan

Really? You think that? They are part of the mould that is used to make the tyres. The chances of you running over something precisely enough to create a puncture through one of those marks are so remote as not worth thinking about. Besides, there is usually a belt for flat protection under there anyway.

The old measure of when to replace a thinned tyre was the number of punctures. Two or three consecutive punctures in short time usually indicate replacement. Apart from that, when the tyre is off for tube repair, just check the thickness (or thinness) of the casing around the centre of the tread. A wide, flat profile on the centre also can be another indicator on tyres such as GP4000s.

rfmarotti

This. Anything that was going to puncture your tire by going through the wear indicator was going to puncture it by going through any other part of the tire (at least on commuter/training tires with belts).

rm -rf

A few years ago, one of my GP4000 tires had a lot of miles, with the wear indicators almost worn off. I cut the tire apart to check the tread depth. When those wear indicator holes are gone, the tread is just paper thin. They don't try to fool you into tossing a tire too early.