Any kind of formula for knowing when to replace tires (besides the obvious gash in the tire)? Since road tires have no tread you don't have that visible gauge. I'm thinking I'd rather do preventive maintenance than be replacing because I got a flat on a ride.

Some tires (Continental GP4000S for example) do have tread wear indicators molded into the tires.

My experience is that usually something else goes wrong (sidewall cut, damaged belt from a puncture causing flats, etc.) before the tread wears out, so I just replace as needed.

My Pro3 Race tires wear down the middle so you can see the under-lying structure (threads?). Also, tires will "square off". This is the first step in the wearing out process. Instead of being rounded (new), they develop a flat area that rides on the ground. If you can't see it, maybe you can feel it.

a puncture doesn't indicate that the tire is worn out necessarily. it means that it is either under inflated or you ran over something sharp and poked a hole in your inner tube.

a sidewall cut, compromised casing from a puncture, or the casing showing through the threads indicates time for replacement.

btw, preventatively replacing your tires won't ensure you flat-free riding. but proper inflation, checking the tires for embedded debris and such can help reduce the risk.

I've only replaced a tire once because it wore out. All the other times were due to cuts/gashes/holes, etc.

So lady...how's that clip-in/clip-out thing going?

I still have a training tire on the front that has something like 10-15 small gashes in it. I patched it with dollar bills. Still works fine. Otherwise, I've never replaced a tire simply because they wore out. That front wheel has something like 3,751 miles on it (on my commuter no less now).

But when you're ready, go with GT4ks Indicator makes life easy.

newbie hi...when you see your tires always flat. and repaired it. and still flat. it means you need to change it.i repaired the interior but its still flat so what i did is to change the exterior of the tire and its fix.

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