I keep getting punctures with road bike tires riding the street in Baltimore. I know they are not the cleanest but I should not be getting a flat every single time. Using Continental Gator Skin and Continental 28mm tubes on my Trek hybrid, which I converted to dropbars to make as many improvements without blowing the bank on a road bike.

I typically keep the PSI around 80-90. These are new tubes and tires as I thought the first flat was related to having tubes and tires that hadn't been replaced in 5 years. However, that was not the issue. I was able to identify one cause being a 3-4mm glass shard that punctured the tire and tube. This most recent puncture shows no sign of puncture on the tire for a very tiny circular puncture on the tube.

Can anyone suggest a couple reasons why I would be consistently getting flats other than road conditions?

Should I consider getting some commuter tires instead?

  • For other readers' reference, if the OP is in Baltimore City (in the US), then it is relatively common to find broken glass on the streets. Baltimore has a few rough spots (and I used to live there).
    – Weiwen Ng
    Commented Oct 28, 2020 at 18:23
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    Check the rim tape condition. Look if there are any spokes poking through
    – thelawnet
    Commented Oct 28, 2020 at 18:45
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    I should clarify that the punctures are coming through on the outside of the tube that would be exposed to the tire and indirectly risks from the road. Wouldn't a spoke puncture show up on the inside of the tire?
    – Rory
    Commented Oct 28, 2020 at 18:48
  • Did you find anything when you checked the inside of the tire? I once had a short piece of wire (c. 5mm) work its way through the tire and give me a puncture. Not visible from the outside at all, and I had no idea how long it had been working its way in.
    – DavidW
    Commented Oct 28, 2020 at 22:28
  • How often do you get punctures? I use Conti GP 4 Season (should have similar puncture protection) and get about 4 flats per year on my 6km, glass shard strewn city commute. I guess you either have to live with it or get some really puncture resistant tires like the Schwalbe Durano Plus.
    – Michael
    Commented Oct 29, 2020 at 8:11

2 Answers 2


First thing to check for is sharp foreign objects embedded in the tire that poke through to the inside. These can be small enough or not protrude enough to be invisible, but can poke a small hole in the tube over time.

As this has become a chronic problem I'd thoroughly inspect the insides of your tires. Remove tires from the rims and turn them inside out. Use bright light and run your fingertips along the interior surface feeling for small sharp objects in the rubber. Run your fingers both directions to catch objects embedded at an angle.

  • Also fold the tires double with the outside out, (go with the build of the tire, so you do not damage it,) so you can find tiny things embedded in the outside of the tire.
    – Willeke
    Commented Oct 28, 2020 at 19:05
  • That's a good point. I was doing that earlier but may need to find different lighting conditions and pay closer attention to anything that feels sharp
    – Rory
    Commented Oct 28, 2020 at 19:10
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    @Rory rubbing a cotton ball along the inside of a tire can sometimes snag on things that a calloused finger tip would miss
    – Paul H
    Commented Oct 28, 2020 at 19:18
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    @Rory you can also use an offset to try and isolate a small sector of the rim. Always fit the tyre so the logo is at the valve stem, then when you find the hole in the tube, lay it off against the rim and tyre, and it will give you about a 5 cm length to investigate closely.
    – Criggie
    Commented Oct 28, 2020 at 20:22
  • Thank you both for those suggestions I will give those techniques a try. I was just wondering what a good way to detect these issues in the future would be and that line up of logo to valve stem makes a lot of sense.
    – Rory
    Commented Oct 28, 2020 at 21:04

I kept getting punctures. Now I fit my bikes with good 'puncture resistant' tyres and inflate the tires to the pressure marked on the tyre walls. I haven't had a puncture in three years of bicycling 80km a week in and around Oxford, Britain. So this works for me.

  • Have any recommendations for puncture resistant tires? I'm using continental gatorskin based on a blog post that I saw recommending them. Could have been an affiliate link for all I know
    – Rory
    Commented Nov 1, 2020 at 22:57
  • @Rory we don't do product recommendations in answers as they tend to go out of date quickly. You could investigate tyres like the Schwalbe Durano Plus or Continental Contact Urban. They won't roll as well, or feel as nice to ride, but they should eliminate puncture problems
    – Andy P
    Commented Nov 2, 2020 at 9:18

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