My E-Bike Tire goes Flat without a Puncture?


Getting flat tires is one of the most frustrating things about owning an e-bike. If you’re getting flat tires overnight for no apparent reason (seemingly at random), your tire has developed a slow puncture that needs to be patched up or have the tube replaced. Let’s explore how to identify the problem and fix it to get your e-bike back in action quickly.

The best options for dealing with flats without an apparent hole are to:

  • Check the tube with air bubbles
  • Listen for escaping air
  • Checking for sharp objects in the tire
  • Check the valve itself
  • and perhaps to replace the tube or tire

Check extremely carefully for a tiny hole in the tube

Spotting holes in a tube with the naked eye is not easy, and can be time consuming. A great way to quickly find holes quickly therefore is to immerse the tube in a bucket of water to spot air bubbles escaping.

To do this, fill a large bucket or container like a bathtub with water. Partially pump up the tube, if there isn’t already some air in the tube. Put a section of the tube under the water – start near the valve to have a visual guide, so that you make sure that you do in fact check the entire tube. Gently squeeze the opposite end of the tube to create enough pressure to force out some air. Slowly work your way along the tube, immersing each part of the tube, until you find a hole. Mark next to the hole with a permanent marker or with a white correction pen (Amazon link) and keep going until you’ve checked the entire tube.

When you’ve checked the entire tube and marked all the holes, make a decision – do you patch all the tube or replace it? If there are not many holes, perhaps 3 to 4 maximum, patching it is a good option. If you have an older tube covered in holes – chuck it out and get a new one. It’s not worth your time to patch a ton of holes when the tube is likely worn out in any case.

Check extremely carefully for sharp items in the tire

If you keep getting lots of flats in a row, or your tire is quickly going flat overnight, it’s possible that a very small, sharp object like a piece of wire that fell off the back of a truck or a shard of glass has worked itself into the wall of the tire causing the tube. Run your fingers carefully along the inside of the tire to try to find it.

If you cannot feel anything, try turning the tire inside out to spot them visually. It helps to have good light, such as a desk lamp pointing directly at the tire. You may be able to spot the glint of a sharp object using this method. If you have an air compressor in your garage, give the inside of the tire a quick blast of air, which will quickly expel any loose objects inside the tire. If you don’t have an air compressor, wipe around the inside of the tire with a rag. With luck, any sharp object will snag on the rag, removing it without cutting your finger.

If you find sharp objects in the tire, that’s good news- you won’t get any slow punctures in the short term. Check the outside of your tire regularly so you can spot larger sharp objects which may have become embedded in the tire after a ride.

Check that the valve isn’t leaking

Sometimes the offender is the valve itself. If the valve leans in a certain direction it may cause a leak in the tube. You can identify if this is your problem by partially inflating the inner tube, immersing the valve section under water, and squeezing the other end to create more pressure. Try wiggling the valve around to see if that opens up a hole. If you spot bubbles near the valve, you’ve identified the issue. Depending on where exactly the leak is, you may not be able to patch the leaks and will have to get a new inner tube in this case. If the tube is old and worn it may be a better idea to simply replace it rather than patch it up.

Replace the inner tube

So you’ve identified leaks with the water method or by listening for a hiss of escaping air. If there are multiple small holes in the tube, it may be not worth all the trouble of patching all the holes up and risking another leak soon afterward. Your best option in this case, is to simply get a new inner tube.

Replace the tire with a puncture-resistant tire

If you keep getting slow flats even after checking the tire wall as described above, your best option is to replace the tire itself to stop it causing more slow flats over time. This avoids wasting your commuting time or your precious weekend leisure time on your e-bike simply because you keep experiencing flats.

A puncture-resistant e-bike tire will save you lots of time, headaches and money in the future. I frequently ride through an area that has lots of broken glass on the pavement, and having puncture-resistant tires has saved me on countless occasions. Having the heart stopping “crunch” of rolling over glass is no longer so stressful and costly!

See here for a list of puncture-resistant tires to consider if you are getting lots of frequent punctures.

Read Next

Conclusion

There is nothing more frustrating than finding out in the morning that your e-bike tire is flat and you will miss your commute. Luckily, there are steps you can take to quickly check your tube and tire to quickly get back in the saddle. If you keep picking up sharp objects in your tires, perhaps due to lots of glass on your route, consider getting puncture-resistant tires to avoid future headaches.

Nikolaj Carlsen

Nikolaj loves cycling! He currently owns two bikes. He used to commute to work with a car but switched to an e-bike in 2017. He loves e-bikes and sharing his knowledge on everything cycling related. He has been part of the Amped Cycling Team since early 2020.

Recent Content