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So I started riding my 10 year old MTB again and got a flat front tire around 4 miles away from home. Being a novice, I decided to ride it all the way home. Found a hole in the inner tube and patched it up, pumped up and was good to go. Until it punctured again and again and again.

I've now got 3 punctures on the inside of the tube (i.e. on the rim tape side) and one of the newest punctures on the outside / top of the tube (i.e. inside the tire wall).

I've decided to buy a new tube but really don't understand what is causing the punctures and think it will happen to my new tube, so want to understand what I should look for. Bearing in mind that my bike is 10 years old and I don't want to spend a great deal of money as I will eventually buy a new one.

I inspected the tyre itself, it appears to have some damage to it, for example when the tire is pumped to 55 PSI, I can see small cracks in the side wall, these are very few and slight. Also, when the tire is off, the bit of the tire that grips inside the alloy is slightly shredded (i.e. tiny bits of rubber have come off). But this stuff is only visible if you look at the tyre with a close eye thoroughly, your average joe can't spot these bits of damage so I am curious whether this damage is enough to warrant a tire replacement or enough to be causing these punctures.

I inspected the inside of the tyre to look for debries or anything sharp in there that might be poking the tube but I can't seem to see anything, the tyre itself pretty much has brand new tread on it and has no holes / punctures.

As the tube is mostly getting punctured on the rim tape side, I looked at the rim itself and it also seems to be fine, however there is places where there is small bits of paint loss on the rim, these places are very slightly to the right of the rim tape so if they are sharp enough then perhaps they can puncture the inner tube? I ran my finger across them and they didn't feel sharp. It's hard to tell if they are damaged from me riding on the flat or just imperfections in the paint given the age.

Also, there are punctures on both sides of the tube now so it can't just be the alloy, my initial theory or hope is that given the tube and tyre are 10 years old now, the tube rubber is just weak and creating holes on its own? Is that possible?

So my question is, what can I do to investigate this further? What products do I need to buy or replace? Inner tube is coming tomorrow.

  • How old was the tire and tube? Possible with age there has been some degradation in the rubber. Possible that just some grit is just finding it's way around the tube and consent friction and pressure are causing the problem. Cracking in the tire side wall would suggest there is a bit of age there so probably should be looking at a new tire – Hursey Jul 21 at 23:28
  • The tube is most certainly for the dogs, and riding 4 miles on a flat is one of two ways know to me to also structurally damage a tire. (The other is a misaligned brake pad.) – Karl Jul 22 at 2:13
  • @Hursey Cracks in the side of a tire are chemically unavoidable, if you actually ride a bike. The process is called environmental stress cracking and it is due to ozonolysis and bending, resulting in crack growth. And unless you ride too long (weeks) with little air pressure, they stay purely cosmetic for many years. Riding on a flat destroys the tire's carcass. That stays invisible until the whole thing ruptures. – Karl Jul 22 at 2:24
  • @Hursey it is 10 years, very old now. – KillerKode Jul 22 at 13:15
  • @Karl I guess a good side question is why a damaged tire is actually a problem and what the consequences are. Can they cause punctures? I raised another question here: bicycles.stackexchange.com/questions/69823/… – KillerKode Jul 22 at 13:23
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Completely remove the tire, tube. Check the rim tape is sitting correctly, and remove that. Clean the rim of any debris that might have go inside it and under the rim tape.

With three punctures in the inside take a very close look at the rim tape for any sign of damage. Also check the rim for sharp burrs than may have occurred due to riding on the flat. If the rim tape is looking good, clean it and reinstall. If in doubt, get a new one.

Its possible that the tube suffered a lot of damage from riding flat, I would put in a new tube, if that punctures, I would then replace the rim tape and tire (and maybe another tube).

Your tolerance for spending money and putting up with ongoing punctures determines when to buy new items. I really dislike punctures, so would be replacing rim tape, tire and tube immediately.

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  • Ok butt what about the puncture on the other side of the tube (i.e. not the rim tape side). How do you think that one is caused? Have ordered a new tube, will take a few days to arrive now though so will open up the tyre and inspect again today hopefully. – KillerKode Jul 22 at 13:09
  • I replaced the inner tube and rim tape, cleaned everything very thourghouly and it no longer punctures. I think the old inner tube was just too old / got very damaged after riding the flat. You were right, thanks. – KillerKode Aug 10 at 21:10

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