# Do tubeless tyres explode more easily than standard one?

Yesterday I was at a bar with a friend with our bikes parked near us and his bike's front tyre (a tubeless one) exploded.

When we went to the bike shop, they told us that tubeless tyres explode more often than standard one especially during hot weather.

After searching on google, I could not really find any proof of that.

Are there any evidence that they do or was it just the guy from the bike shop trying to sell us a new (wheel + tube + tyre) instead of just a tyre?

• Tyre pressure was about 3 bar / 43 PSI.
• His bike is a road bike
• The outdoor temperature was 28°c (82 F)
• A somewhat dishonest salesperson. 3 bar is a rather low tyre pressure. On racebikes the tubeless run at 6-7 bar without exploding. This was most likely caused by a hidden cut. Aug 9, 2019 at 8:07
• Did the tyre explode, or did it blow off the rim? 43PSI is well over spec for some types of tubeless rim Aug 9, 2019 at 12:05
• @AndyP For me it exploded, we hear something that, for me did look like a gunshot (I've never heard a real one) . And there was a 2cm (0.8in) hole on the tyre.
– f222
Aug 9, 2019 at 12:09
• Some confusion in the pressures, because the tyre's width has not been specified. "3 bar is a rather low tyre pressure" <-- for a road bike "43PSI is well over spec" <-- for a MTB/fatbike which might run as low as 5-10 psi. What size tyre was on the bike ?
– Criggie
Aug 9, 2019 at 12:39
• The likelihood of a tire exploding depends only on the tire, not on whether it is tubeless or not. The tube simply does not provide any relevant force to counter the pressure, it only acts as a seal. The force to withstand the pressure within the tire comes from the tire only, and if the tire ruptures, so does the exposed tube. However, that reasoning depends on the tire brand being the same in the tubed/tubeless case, if you compare different tire models, the image can change. Unfortunately, I don't know whether typical tubeless brands are more prone to exploding than typical tubed brands. Aug 9, 2019 at 20:31

TLDR - I have been commuting daily on tubeless tires now for about 3.5 yrs. In my 20 years of daily cycling experience, I have had a number of tubed tires spontaneously rupture due to heat, especially if a wheel set was left in the back of a car! I haven't had a tubeless tire explode yet using tubeless specific rims and tires.

### Hypothesis: Previous damage

My best guess is that the tire was already damaged (e.g., road debris causing a partial cut that could be re-sealed) and then the added heat could have caused it to rupture. A damaged tire casing can undergo rapid decompression regardless of whether you are running tubes or tubeless. In the case of tubes, if the tire cords (the internal structure that actually counteracts the force from the pressurized air) gets damaged the tube can escape out of the tire carcass and rupture as a result. Similarly, in the case of a tubeless setup, if the tire gets damaged in such a way that it can no longer support the pressure, a the tire would rupture in a very similar way as a tubed tire.

### What about the shop's claim?

Tubeless tires can also rupture if their is an unsuitable tubeless tire/rim combination. For example, in the early days tubeless specific rims were rare, so people often converted regular rims to a tubeless setup. It can be done, but the tolerances are not as good, one problem is that the tire bead can climb over the rim hook if pressure is too high for the tire/rim combination (many wheels are slightly undersized (i.e., out of spec) for easy of tire mounting).

With a tubed tire this is less of an issue as the friction against the tube helps to prevent the bead from climbing, even if the rim is slightly out of spec.

Ad hoc tubeless setups were also less of an issue in mountain biking because mountain bikes run lower pressures. That said, tubeless is still a bit of a wild west when it comes to road tubeless. There unfortunately isn't a single standard and some wheel/rim combinations (even if specified as being tubeless) can fail under high pressures. Further adding to the confusion people may also be experimenting with "road tubeless" with regular road rims which will be highly unsuitable due to the higher pressures typically used on road tires.

I suspect these issues may be what the shop was referring to, but it's hard to assess as we would need to directly speak to them.

That said, I don't think this was you issue. In your description you also described the tire has having a gash, as such I suspect the tire failed due to damaged as was described above, not from a poor tire/rim combination. As such, the shop's claim may be a bit of a red herring in terms of your described experience.

### So are tubeless more dangerous?

I doubt it. Anecdotally, I have been commuting daily on road tubeless tires for about three years, including one tire that had a partial sidewall gash that resealed (descending too fast on very rocky gravel trail), and never had the tire explode like you describe. Furthermore, I have never had a flat tire in those three years. I would suggest, that there is higher "risk" with tubed tires, as getting an unexpected flat can easily cause a crash.

In terms of your experience, if this was the result of tire damage, it was likely the culmination of a number of low probability events. Partially damaged tire, that resealed, then increase pressure due to heat that didn't cause the sealant plug to fail, but initiated a structural tear in the tire due to the earlier damage. Because of the low probability of these events it is hard to assess how likely this type of event is by tire type.

• Excellent answer, and I'd agree that overall tubed tyres may be higher risk. The last front tubeless tyre I took off had sealed 20 small holes, each one of which could potentially have caused a crash had it been a tubed tyre. Aug 12, 2019 at 12:24
• @AndyP some might think “how dangerous is it really? You slow down and pull over when you feel the tire getting flat.” Years ago I had a front flat while going 80 kph down a mountain with traffic when the front started to go flat. There was no time to slow before I was essentially riding on the front rim. Decelerating with the rear brake was problematic as it still shifts weight to the front which made the bike dart around, but I couldn’t really steer or correct. It took what felt like it took ages to finally come to a stop. Flats? No thanks, I’ll pass. Aug 12, 2019 at 14:49