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I got a flat on my back tire and bought a new innertube. I put it on my bike, filled it up but it lost all air again within minutes. I took the new tube out, pumped it up to find out where the hole is, but I couldn't find a hole and the tube didn't lose any air.

I installed the tube again and the tire went flat within minutes. I repeated this process a few times with the same result.

My bike is an E-Bike and I am reluctant to take it to a bike shop because in my area they charge some extra money for E-Bike repairs.

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  • Depending on your ebike it could be reasonably heavy, which translates into significantly higher pressure than you could put into a tube that's not mounted in a tyre. Higher pressure means faster leakage...
    – DavidW
    Aug 11, 2020 at 3:51
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    @DavidW: e-bike tire pressure is comparable to any other type of bike. My e-bike tires run at 60-70 psi. The extra weight simply means a larger contact patch for the tire as compared to a lighter bike. It doesn't change the pressure inside the tube.
    – Peter Duniho
    Aug 12, 2020 at 0:26
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    "...in my area they charge some extra money for E-Bike repairs" -- not that this has anything to do with the leaky tube, but...for what it's worth, there is some justification for charging extra for e-bikes, owing both to their additional complexity, but even just to their weight. Work on an e-bike often involves a heavier-duty stand than would otherwise be required, and this is a bit of specialized equipment the cost of which has to be recouped. Of course, extra fees shouldn't be excessive; but if they are reasonable, no reason to begrudge the shop the extra money.
    – Peter Duniho
    Aug 12, 2020 at 0:28

1 Answer 1

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Just check the tube more carefully, some holes are very hard to spot. Put it into the water and look for bubbles. You must fill the tube and press it. Try hearing any hiss when pressing the tube in the air. There could still be a thorn in your tyre, we have many similar questions. It does not matter if it is an e-bike or not.

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    I experienced pretty much the same thing just last week - I put some air in the tube and it didn't seem to leak. Then I rewatched this Park Tool video youtu.be/T0F_hibWHlU?t=79 - the thing I had forgotten is to inflate the tube to roughly twice the normal size, it will look huge. But it definitely worked and I found the small hole in my tube.
    – user39927
    Aug 10, 2020 at 21:07
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    water trick works every time!
    – DerekG
    Aug 11, 2020 at 19:47
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    Note that when you fill the tube to check for leaks, you should OVER-inflate it, such that the diameter of the tube expands by maybe 1/3rd.
    – Daniel R Hicks
    Aug 11, 2020 at 20:47
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    ...and consider wearing earmuffs/defenders when doing so, cos they go BANG quite loudly.
    – Criggie ♦
    Aug 12, 2020 at 3:42

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