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I have a set of tires where one of them blew off the rim on my bike after I slightly over-inflated it.

I originally asked a question about this here, and there are more details at that link. The tire did not appear to sustain major damage from the blow off, just some mild scuffing where the bead popped out over the rim. When I took both tires off after this, I did notice they're quite loose on my specific rims (easy to remove with hands, no levers required), so that's probably why it happened.

I was thinking of posting these online for free, with an explanation of what happened, and ask that whoever takes them just state clearly to me that the know the implications of a tire blow off, they know enough about bikes and tires to determine if the tires will be safe on their bike, and will take responsibility for any subsequent injury or bike damage if the same thing happens to their bike.

The tires seem to be in good shape and I think someone who knows bike can determine if it's safe to use them on their bike. I just don't want some noob throwing them on their bike and having the same thing happen while riding, leading to injury, etc.

So I have a several part question:

  1. Can a tire that blew off one rim be safely used on another rim? If so, are there any special stipulations?

2. Is it OK to give those tires to someone else, assuming I provide a detailed explanation of the blow off issue I had, and ask them to stipulate that they understand the dangers and know how to determine if the tires are a good fit for their particular rims? Or, should I just throw them in the garbage? Feel free to provide your personal opinion on this one, I don't think it has a concrete answer.

3. Assuming I'm clear about the issues as outlined above, are there any legal implications (i.e. liability for me) if someone else has a blow off and injures themselves with tires I provided "as is"? I'm located in Canada.

Thanks.

migrated from bicycles.meta.stackexchange.com Feb 8 '18 at 16:15

This question came from our discussion, support, and feature requests site for people who build and repair bicycles, people who train cycling, or commute on bicycles.

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    I edited the questions. Question #2 is opinion and #3 is legal opinion. We don’t deal with those here. I didn’t erase them, I struck them out. If someone is answering #1, they could also potentially respond to #2 and #3. But the real question is #1. – RoboKaren Feb 8 '18 at 16:22
  • ^^^ this is on the basis of my understanding of the discussion on the linked original question in meta. Rollbacks or amendments by OP or others are welcome. – RoboKaren Feb 8 '18 at 16:23
  • Does your rim have bead hooks to begin with? Some don't, and on those blowouts are easy to have happen. – whatsisname Feb 11 '18 at 18:31
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I have a MTB where the tyres can simply be removed by hand once deflated. The tyres are at 50~60 PSI normally. But I can feel that they engage the clincher bead fine when inflated.

My guess is that your tyres never hook into the rim properly, and then overinflating found that area of the bead that wasn't fully seated.

As for the social side, as long as you clearly advise the recipient that you're giving them away, because they didn't stay seated properly on your rims then its the recipient's choice whether they use them or not. I wouldn't want to see anyone hurt, but they'll be adults and can make their own choices. Just help them to make an informed choice by sharing the history.

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There are exactly two possible reasons for the blow-out:

  1. You misinstalled the tire, so it was so unevenly sitting on the rim that the failing part was way too high on the rim for the bead to make sufficient contact with the rim. It must have been very low at almost all other parts of the rim for this to be possible.

    If this is the case, well, you may be fine with keeping the tire. Just make sure it's properly seated all the way around the rim after inflating.

  2. The bead is weakened. (Due to age, wrong installing/removing, other mistreating, whatever...)

    If this is the case, don't use that tire anymore. Throw it away. Your tire is one of the most security critical parts of your bike, you don't want them to fail abruptly when going downhill.

If your tire is a city/touring bike tire, the first failure mode is next to impossible. I don't know how racing bike or mountain bike tires behave, but the touring bike tires I use are way too stiff to blow out in the first failure mode. And no tire I have ever installed myself ever blew out in that first failure mode.

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The question is WHY the tire blew off the rim:

  1. The tire was poorly installed. This would be the most common reason for such a failure.
  2. The tire is simply the wrong size. Not only is it possible to install some tires on the wrong diameter rim, but also a tire that is too wide or narrow for the rim may blow off.
  3. The tire is a poor fit to the rim. Some manufacturer's tires are a hair large or smaller in inner diameter than "standard", and the same is true of the mating surfaces of rims. Ie, some tire-rim combos are just a poor match.
  4. The tire bead failed. This could be due to damage while installing, or it could have "just happened".
  5. The rim failed. It's not at all uncommon for a rim to be worn through by rim brakes to the point that the rim side buckles outward. This may or may not be obvious on first inspection of the rim, but should be obvious if you look for it specifically.
  6. The tire was simply overpressured. This is unlikely, but can occur when tire fit is poor.

There is also the question of whether the tire was damaged in some way when it blew off. Not only may the failure have been due to a failed bead, but also the rubber around the bead may have been damaged, or the tire may have contacted the frame or other parts and been cut before it came to a stop.

  • I've seen rims with no hooks for the bead too, which means just a slight misalignment and high pressure is all that's needed for a blowout. – whatsisname Feb 11 '18 at 18:32

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