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I only bike for pleasure and sometimes to get around. I know very little about bikes.

A few months ago I got a B'Twin mountain bike. Where I live now I do not feel safe biking in the city so I only use it on the weekends when the weather is good to get out to nature (on some otherwise clean looking dirt roads where many people bike).

Despite the light usage I already got a flat three times. In the past I used to bike to work every day (with a similar but simpler bike) and I have never gotten a flat in several years.

What could be the reason for all the flats and what I can do to prevent them? The first time I got a puncture I took the bike to the shop to get it fixed, so I don't know what caused it. The second time I thought it's time I learnt how to do this myself, so I changed the inner tube alone. I found a thorn. The third time I found a small piece of metal wire stuck in the tyre, which may or may not have been the cause of the tiny hole in the inner tube.

I don't have great job stability so I expect to have to move often (1-2 years) and unfortunately I cannot keep a bike for a long time. Thus I am looking for a solution which is not too expensive. While many people will consider this bicycle quite cheap, for me it was the most expensive bicycle purchase so far ... as I said unfortunately I can't make a long-term investment.

Am I getting flats because I go on dirt roads too often?

Or is it because of the quality of the tyre? Should I change that? I can find different compatible tyres between 9 EUR – 40 EUR and practically all are advertised as puncture resistant, so it's not clear to me if there is a significant difference between them. What I care about mostly is avoiding flats, not high performance (low weight, etc.)

Should I consider a "puncture proof" inner tube instead, with the slime inside? I read mixed opinions about those and it seems like it's not the best choice for my situation.

Should I consider a tyre liner instead?

To sum up, I am looking for an affordable and simple way to reduce the frequency of punctures. I need an affordable way because unfortunately I may have to sell the bicycle in less than a year.


Notes: I keep the pressure around 50 psi; the tyre has 35-65 written on it. I read this post where the ultimate solution was to change the tyre, but it's not clear if it's also the right solution for me, and it's not clear if I really have to go for an expensive tyre go get useful puncture resistance, or if the standard B'Twin brand will do just a well (even if it otherwise offers lower performance).

  • 1
    Flat tire is typically bad luck, but you should always check where the puncture is and check the outer tire/rim tape accordingly. There may be particles between tube and rim/tire that cause a puncture. Also there may be particles or holes in the outer tire. – mkpaa Apr 21 '16 at 11:12
  • Flats are a part of riding. Learn to patch rather than buying a new tube every time I have years-old tubes with a dozen patches that still work fine. – Criggie Apr 21 '16 at 12:44
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    Where is the hole in the tube, on the outside or on the inside (near the rim) ?? Perhaps this posting covers it? – zipzit Apr 21 '16 at 20:02
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If you don't want to spend money on expensive tires, you can opt for tire liners. I've had very good experience with this product specifically when I used to have cheaper tires. I find they did a very good job of protecting against flats. Not a single flat the entire 2 year span I was riding them. I currently use high end tires and don't have a problem with flats anymore, but tire liners are a cheaper option.

The other point is to ensure that you are always using the correct pressure, check before every ride. It sounds like you are already using a good pressure. However, I would go higher, probably up to at least 60 psi to prevent against pinch flats. Due to the nature of your flats, this probably isn't the issue but it could prevent future problems.

Also, listen to @Criggie in the comments. Learn to patch the tire. A patch kit can patch at least 5 punctures and costs about half the price of a tube. You can save even more if you can find a place that sells patches individually and buy the glue/cement in larger tubes. however, the pre-assembled patch kits are nice because they come with everything you need and easily fit in a seat bag so you can fix the problems on the trail.

  • I was worried that if I pump it to 60 PSI it might exceed 65 on a hot day. Isn't that a risk? I think I'll try the liners if the punctures continue. I did get a patch kit, I'll use that if it happens next time. – Filip Apr 21 '16 at 15:44
  • @fllip Take spare inner tubes on your ride, but patch them when you get home. I always carry one, and then one more for every 50 km I intend on riding, so three spare tubes for a 100 km ride. I've never needed more than one, but I have given one away once. – Criggie Apr 22 '16 at 1:20
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I own a bike shop and one of the reasons I noticed when a tube is punctured is that the rim tape/strip is not in place properly, like it has folded over itself. If you have ridden your bike for a while, the rivets on the rim may have rusted and they create sharp edges that can puncture your tyre. If this is the case, straighten the rim tape/strip to cover the rivets completely. You will have to change the rim tape/strip if that is no longer feasible. If you would like to save on paying for it, ask the bike shop to give you a punctured tube of size smaller than your wheel size. You can cut a strip off the punctured tube and place it over the rim. Make sure that you have cut a hole big enough to push through the tube valve.

  • Thank you for the comments Nancy. I think that in my case the flats care caused by things that puncture the tyre. What is not clear to me is if this is normal, expected an unavoidable given the places I go, or whether it indicates that the tyre is just bad quality. – Filip Apr 21 '16 at 10:02
  • This would absolutely make sense if the punctures through the tube were on the "inside" ie the circle even with the valve stem. Also, I've used three layers of masking tape in place of rim tape and it worked perfectly. – Criggie Apr 21 '16 at 12:46
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Your comment suggests that these punctures are caused by something (thorns, nails,...?) piercing the tyre wall so the issue probably isn't with the wheel or the rim. So the question is should you change tyres to something more puncture resistant?

In my opinion it's only worth changing tyres if the tyre is obviously worn out or is to light weight/low TPI for the riding you are doing and there are lots of other factors to consider:

  • Is there something in the tyre? If you don't get all of the foreign object that caused the puncture out of the tyre it can just keep re-puncturing. Next time it happens take the tube out carefully so as to keep track of where on the tyre the hole was, give the tyre a thorough inspection (inside and out) for anything stuck in the carcass.
  • Have the hedgerows just be trimmed? Where I live at certain times of year the local farmers trim their hedges liberally distributing thorns across the tracks. Incidence of punctures goes up!
  • You also need to be aware of the Clustering Illusion, if getting a puncture is a random event experiencing a cluster of 3 or more can just be the laws of chance at work! I've had it happen to me, punctures every ride for 2 or 3 weeks and then nothing for months - all on the same tyres.
  • Snakebite, are you just getting holes in the tube or is there always something to take out of the tyre? If you can't find anything in the tyre it might be that your pinching the tube between the tyre and the rim when you hit an obstacle; however the high pressure your running should prevent this.

One last thing to consider is tubeless, you can get a conversion kit that allows you to run the wheel with no tube but with a sealant that plugs holes; this is how I run all of my bikes. It does however bring it's own problems, you can get a cut in the tyre that's too big for the sealant to cope with and access to a compressor is helpful when setting up a tubeless system.

1

Well firstly, no, you are not getting flats because you are riding dirt roads too often - this seems like exactly the terrain the bike is designed for.

Your punctures are most likely just a result of bad luck, however the cheap tyres common to entry level bikes are often very thin and puncture prone and may also be the culprit.

The best solution would be to change to a heavy duty touring type tyre with a thick anti puncture layer, however in the short term at least this will also be the most expensive option.

If you get tubes with removable valve cores you can inject any brand of well regarded sealant (Stans/Conti/Bontrager/OrangeSeal etc) - this is more hassle, but should resolve your problem more cheaply.

1

The first thing you should look at is, what the puncture looks like:

  • Is it a puncture from a sharp or pointy object, like a spine for instance
  • Or does the tube has a small, clean cut on the side.

You can tell by inspecting the tube, but also by how quickly the tire loose pressure. If it's slow, it's most likely the first case. If the tire loose all pressure within 5-20 seconds, the second.

Now, since the pressure you use is really high, it's most likely the first option, ie a spine or some sharp object. The reason is, the second option occurs when the tube gets pinched between the rim and the tire, usually while passing a slightly bigger bump/hole. Your pressure seems rather high to permit that. However, paradoxically, high pressures means higher chances to get punctures from spines, etc.

Here's what I would advise:

  • Get better tires. There's a world of difference between a 9EUR tire and (without going with top of the line models) a 25-30EUR tire: different compounds, different carcasses, different threads, etc. Tire thread and compound play a big role in puncture resistance. Mid-range tires will not be as sensitive to punctures; and most of the time the biggest difference with high end ones is the weight. At least, get something with folding beads, not wire beads. You can also find hardened versions, but they're probably overkill for the type of roads you describe.
  • Use lower pressure. 50PSI is way too high
  • Check the type of puncture you get. If it is the tube that gets pinched, check that you install the tube correctly. After you install the tube, always perform a quick check by pushing on the side walls with you thumbs and see that the tube is not pinched between the bead and the rim
  • If performance is not much of an issue, I wouldn't advise to use sealant or puncture-proof tubes; but rather a tire liner, as they're much more efficient.
  • As advised above, make sure you have a good and well-centered rim tape
  • Now I have an answer suggesting 60 psi and this one suggesting lower than 50. I'm confused! – Filip Apr 22 '16 at 12:07
  • The pressure you're using is already way more that enough to prevent pinch flats. Even at 40 psi you shouldn't get pinch flats. – Guillaume A May 5 '16 at 9:43
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I had a run of punctures over the winter. One or two a week, always on the front wheel. Drove me crazy, especially as I commute on my bike. I had expensive Schwalbe tyres, with puncture protection.

A friend got me to check over my tyre to see if anything was stuck in it. Eventually I found some tiny slivers of glass were basically embedded in the tyre. Every now and again one of these slivers would poke through into the inner tube.

Then the tyre would deflate. I would fix the inner tube with a repair kit. The pressure would hold, but as soon as I was on the bike, I guess there was enough force on the slivers of glass to repeat.

The real bummer was that I was running my fingers inside the tyre every time and not noticing any issues. I learnt this as a tiny wire thread had once given me a similar repeat-flat. But the glass couldn't be felt at all! I had to squeeze and fold the tyre on the outside until I spotted the 3 or so bits of glass! They are removed and I haven't had a puncture in 4 months.

  • This can be somewhat hinted at by installing the tyre/tire the same way around and in the same place relative to the valve. That way you know if you're getting punctures all in the same place that its related to that spot on the tyre/rim. Standard practice is put the largest sidewall logo at the valve stem position, with the tread pattern correct for the rotation. – Criggie Apr 22 '16 at 1:18
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I would guess that your tire was damaged therefore making it easier for thorns and other sharp objects to penitents the tube. Check your tire for holes or tears. If there are no holes or tears the tires may just be cheap soft tires. I had the same problem on my bmx bike. I ended up changing the tire and never had constant flats again.

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