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I have a next to unused GP5000 road tire, 25mm, which unfortunately has three cuts in the sidewall. I would like to ask, if it these constitutes a safety problem - or if they rather are to be looked upon like regular cuts in the tread. What is the verdict: dead or not dead? Thanks, Morten

enter image description here enter image description here

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    I don't think it is a fake. I bought it second hand from a trustworthy person, who has gone tubeless. He also reimbursed me. So no harm done in that respect.
    – Jensen
    Commented May 27, 2020 at 11:54
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    Sliding the sidewall against sharp rock or curb does that kind of damage. Don't ask how I know.
    – ojs
    Commented May 27, 2020 at 11:58
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    It might get you ten miles, but I wouldn't bet on 100. Commented May 27, 2020 at 11:59
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    @Jensen any chance you can post a picture from the top angle, I am interested to see the tread pattern, Grand Prix Continentals have a distinct pattern.
    – Dan K
    Commented May 27, 2020 at 12:44
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    People - answers in answers please. Comments bypass the up/down vote process.
    – Criggie
    Commented May 30, 2020 at 23:41

5 Answers 5

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I would not ride that tyre. Pretty sure I can see tube in the second photo, and that's asking for a sudden blowout.

You might choose to put a boot/patch on the inside of the tyre, JUST TO GET HOME.

You might boot it and use on an indoor trainer tyre only. Might be okay on rollers, would make a great front-wheel tyre for a direct-drive trainer (ie, the wheel that doesn't turn at all.)

I certainly would not choose to ride on the road with that ever.

It is dead, buy a new tyre.

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    It does look a lot like tube in the 2nd picture, but in that case there's no pressure in it. I've caused similar damage and the tube was bulging out (a boot got me home then I retired the almost new tyre)
    – Chris H
    Commented May 27, 2020 at 14:49
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Yes, but only to the nearest tire shop. While doing so, put the tire boots in your emergency tire repair kit to the inside of the tire, at the areas where the cuts are. Tire boots weigh next to nothing (three Park Tool TB-2 boots weigh 8 grams), and are also reasonably cheap, in fact so cheap that you shouldn't consider reusing them.

Tire boots are marvelous items, they can turn a tire with a full cut causing the tube to burst, into a tire that is able to contain an inflated tube inside. It's extremely rare to destroy your tire in such a manner that a boot wouldn't at least temporarily fix it.

If you find the tire contains the tube without boots, don't take your chances, use boots nevertheless. It's possible the situation worsens during the trip to the nearest tire shop, and that the tire would suddenly finally cut, and the tube would suddenly explode, causing rapid deflation.

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  • Booting a cut is a great get-home fix. I have several times tried to ride on with a boot, and they fail within a couple hundred kilometres as the boot and tube get pushed through the ever-enlarging hole, thought this is at road-tyre pressures of 80-90 PSI. The cut/tear just slowly grows till the tube and boot is hearneating through
    – Criggie
    Commented Sep 19, 2022 at 9:30
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    @Criggie curious what you used for the boot. I have had good (luck?) forgetting about boots made from US paper currency and others from Cliff Bar wrappers.
    – Paul H
    Commented Dec 27, 2023 at 15:36
  • @PaulH I generally have a plastic coin bag in my toolkit, with USB cables in it. They work well. I've also used gel pouches, but they tend to be messy... you can never get them completely empty so they leak some in side the tyre.
    – Criggie
    Commented Dec 28, 2023 at 7:18
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I'd say it is a simple as that:

If there is any kind of deformation (as clearly shown on the groove above the cut): The tire is structurally impaired and ready to go into the bin. Same for any kind of damage that makes the tube shine through or bulge out. It will eventually fail and you're just waiting for it to do so.

I've been there and finished rides on damaged tires, but as soon as you are starting to think about whether your tires make it through the next ride, don't overthink and replace it.

Even a high-spec racing tire isn't worth waiting for it to fail big time, we're talking about replacement in the range or 50€/$/£, a fatal crash will cost far more if you just scratch your derailleur and bar tape. Therapies and job loss not included...

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In case there is fairy easy repair. Riding similar with 2x bigger defect from a stone, whole side. After some experiments found simple way

  • cut way bigger patch from another tyre (side of good MTB was best)
  • fold over bead to fix its position

Riding on maybe 2x longer yet/still.

It is seems it is not possible to glue like tube as there is big stress and glue will not fix its position for long time.

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Of course not.

Why are you risking your life on the word of a bunch of internet strangers you're never going to meet or be able to hold accountable?

Go to a qualified specialist and have the suspect tyre examined…

Whatever else, please remember that if it does fail and any kind of law-enforcement finds out you Posted this query, you will have no weakest wheel to stand on.

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    What are you talking about? You do realize that this is a bicycle tire, not a car or motorcycle tire, right? Taking a spill from a bike is very rarely life-threatening, there wouldn't be any passengers, and law enforcement is not going to know or care that some bicyclist somewhere had a blow-out. Commented May 28, 2020 at 3:11
  • @Swifty yes, that's not the sort of tyre you'd be likely to use on a kid-carrying bike
    – Chris H
    Commented May 28, 2020 at 19:01
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    Yeah I messed that comment up, got all excited. Rubbie I was actually trying to bridge the gap and bring the focus back to the good point I think you are trying to make, that we should think about others and not only ourselves. Do note that the other answer very clearly says not to use the tyre, it has had a lot of upvotes and has been accepted by the asker - indicating they will be heeding this advice.
    – Swifty
    Commented May 30, 2020 at 20:59
  • @Swiftly Cool; thanks Commented May 30, 2020 at 21:04
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    @HiddenWindshield I will point out that this is a top-quality racing tire. There’s a very real possibility the OP will be riding at speeds high enough to cause severe injuries in the event of a crash.
    – MaplePanda
    Commented Jun 30, 2022 at 17:27

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