My rear tire exploded recently while I was riding downhill from a bridge on my way home.
I don’t know exactly why it exploded, but when I checked my front tire (which didn’t explode), I found a large cut that looked very similar to the damage on the rear tire. Because the cut was deep, I replaced the front tire as well. Both tires were Chaoyang Mini Shark 700x28c.
I then changed my setup:
Front tire: Chaoyang Speed Shark 700x25c (barely used)
Rear tire: Chaoyang Mini Shark 700x28c (brand new)
After a few weeks of riding, I noticed similar damage starting to appear again. The cuts are not as deep as before, but they look the same. This is concerning because the tires are still fairly new.
Even second spare Chaoyang Speed Shark 700x25c tire, which I only rode a few times before replacing, showed similar marks (though not as deep). This makes me think the issue isn’t from long-term wear.
Additional information:
– I use a hand pump without a pressure gauge.
This is the first time I’ve ever had this kind of problem.
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I never had this kind of problem with my MTB tires before, even though I used a floor pump without a pressure gauge. I can’t remember the brand, but I’m sure they were not Chaoyang tires.
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I used a second-hand Panaracer 700x25c tire and put more mileage on it than my barely used one and might be more than my slightly used one (both are Chaoyang Speed Shark 700x25c tires). Despite having more wear, the Panaracer tire has no marks or damage, while both Chaoyang tires show visible marks and damage.
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I don’t think the tires are overinflated or underinflated. The bike mechanics inflated them using pumps with pressure gauges, and when I inflate them myself, they feel only slightly softer than when the mechanics did it.
by NicheJourneyman
6 Comments
It almost looks as though rim brakes are badly set and are rubbing on the tyres.
It looks like your BRAKE is rubbing against the tire and damaging it.
So my advice is to adjust brake pads to touch only the rim, but not the tire during braking.
Your rim brakes damaged the tyre. Adjust them to hit the rim only.
As others have said I think it something to do with your rear brake calliper. If your running it fixed then the easy answer is to get rid of the rear brake and use back pedalling more. Other wise you’ll need to change where your break pads are. It’s a pretty easy fix but I’d still go and have a chat with your local bike shop to make sure it’s not anything else.
100% rim brake, had the same issue when started
It is easy to see if it was the brake rubbing. Take a pic of your pads and we can tell you is it was that or not.
However, I doubt it was brake rub. You would have rubber flakes/dust all over the bead and rim and in the caliper. It would be super obvious.
You stated you’ve been using a pump with no gauge. You state the MTB bike does not have the same issues.
Two thing, your MTB is large volume, low pressure. The road bike is low volume, high pressure. Using a pump without gauge leaves you guessing. This tire needs high pressure. Don’t just do a squeeze test and think it’s ok.
To those who think is the brake, that’s a ok guess, but I’ve been doing this job for 3+ decades. The tire damage is 100% the rim digging into the side wall from under pressurized tires.
Their lack of rubber dust from pad to tire wear is the telltale sign that it is not brake rub.
OP, get a floor pump with a gauge. A decent $50+ pump will have a quality gauge. Cheap pumps have terrible gauges, or none at all.
Do not trust the squeeze method. Firm to the touch will still be well below optimal psi. Especially for the super narrow tire you have.