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Recently, after mis-reading "35-65 PSI" on a tire sidewall as "35-85 PSI" (in retrospect the unusually huge range should have tipped me off), I inflated a tire rated for 65PSI max to 80PSI. A few minutes later it blew off quite violently, giving me quite the fright.

Now I'm nervous about using the tire again, wondering if it will blow off again more easily now, etc.

So my question is a) would you generally continue to use a tire that has blown off a rim once or is best to chuck it, and b) what aspects of the tire and rim would you inspect and what are you looking for to determine if it's safe to keep using the tire? The one I mentioned looks like the rubber around the bead is a little roughed up but not terrribly so. I'll add a picture when I get home.

Thanks.

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    My guess is that it didn't blow off the rim because of the pressure, but because you didn't seat it properly. Always inflate to a low pressure (10-15 PSI), make sure that it is properly seated, then inflate it slowly to the pressure you desire. – Batman May 18 '16 at 18:21
  • Thanks, but I actually pretty much did what you outlined. I generally inflate to somewhere between 15-40 PSI depending on the tire, then go around the tire gently rocking it back and forth cross-wise to encourage the beat to seat before continuing to inflate. Maybe that's not a great way to do this? Also, for interest's sake, the tire is a Schwalbe CX Comp and I noticed in the reviews for it on Chainreaction that a low of other customers found they blow off easily if over-inflated. – SSilk May 18 '16 at 18:25
  • Did you check the line that runs around the tire to see if its at a constant distance from the rim? – Batman May 18 '16 at 20:25
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    Yeah, I'd be surprised you could cause a failure in a sound 65 PSI tire by inflating it to 80 PSI. But I've never been terribly impressed with Schwalbe tires. – Daniel R Hicks May 18 '16 at 20:40
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    In terms of checking the tire, look for a deformed place in the bead, suggesting that the bead failed at that point. – Daniel R Hicks May 18 '16 at 21:26
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I'd change it for a better tire, one that's much tighter on the rim.

You inflated out to only 15 psi over its maximum. That kind of force could easily be generated in a quick turn with the brakes on. If the tire blows off in such a scenario, then you'll be underneath the vehicle you were trying to avoid.

Go to your LBS, and explain that you want a tighter tire. They should know which tires are tighter. Don't let them argue with you, this is about the safety of your life.

(While tires and rims are supposed to be a nominal size, some are slightly larger and some are slightly smaller. Having a large tire on a small rim makes changing tires easier, but at great risk. Hence my advice to find a tighter tire).

  • PS Happy anniversary :-) – andy256 May 19 '16 at 2:37
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    Thanks for the feedback. I've decided to buy some new tires. I put one of the ones in question back on yesterday just to measure its inflated diameter and I noticed I was able to easily put it on by hand with no tools/ grunting/ sweating/ cursing, suggesting to me it's probably just a loose fit for my rim. – SSilk May 24 '16 at 16:14
  • Yes, that's a good indication! – andy256 May 24 '16 at 22:38
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I had this problem repeat itself for various makes of tyres once. For one of my wheels. I finally realised that the rim tape went too far out of center, lifting up the tyre bead enough to make the tyre lift off after a couple of minutes when at full pressure.

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