Five Most Common Causes of Flat Tires on Bicycles

Alessandra Coretto Photography

Alessandra Coretto Photography

Over the past week, I've been having an insane amount of trouble replacing the tube in the rear wheel of my Diamondback commuter. For nearly two years, I rode it 20+ miles everyday to college without a single hiccup or repair, and suddenly, I had a flat to fix. Of course, getting a flat tire isn't a big deal; it's bound to happen from time to time, but this instance has been particularly odd since it still hasn't been resolved. 

The Gist of What Happened

Basically, I woke up one morning and found the back tire flat. No big deal, right? So I went down to a local bike shop and bought a replacement tube, went home, and swapped it with the old one. I reinstalled it, gave it some air, and the whole thing was as good as new. The next morning, I went to go ride it again and saw that it was flat. Clearly at this point, something must be wrong with the rim or the tire or whatever, so I decided to bring the entire wheel to the bike shop and have them look at it. The mechanic there was cool about it and suggested that my spokes were too long, causing punctures in the tube. He said he would shave them down, throw on some new rim tape, and get it all back together. I agreed with him and left the tire at the shop overnight. A couple days later, I picked up the tire, took it home and reinstalled it. However, as soon as I got it back into place, the tube popped again! I was incredibly annoyed. I mean, what the hell could be going on with it? I instantly took the wheel back to the bike shop and aired my frustrations. The mechanic gave it another look and swore that everything was sound. He replaced the tube again, inspected the rim and tire, and sent me on my way. When I got back home, I reinstalled the wheel and left the bike sitting there for a few days. I was using another road bike in the meantime and I didn't want to deal with another potential hassle. I rode my other bike, not paying too much attention to the Diamondback in the garage. After a long commute later in the week, I was parking the road bike and glanced over at the Diamondback. The tube was holding up fine, and so I decided to take it out for a short ride. I flew the down the street without any issues and turned around at the nearest stoplight. As I was peddling back up the street, I felt the tire blow out again. A loud hiss erupted, deflating for about 30 seconds until the rim scrapped against the pavement. I hopped off and shouted a few &%#!s and God-%$#&! before pushing the bike the rest of the way home. I decided not to take the wheel back to the mechanic. I figure he's probably fed up with the problem as much as I am. Instead, I did a little more research and narrowed down my problem to these 5 most common reasons for a flat tire:

1. Your Spokes Are Too Long

When rebuilding a wheel or fixing a broken spoke, occasionally, the tip of a spoke with stick through the rivets inside the rim, causing it puncture the tube with really small holes that leak air over time. Also, if you've had any hard impacts recently, a spoke can jam through the tube and cause some serious damage. To alleviate this, make sure that any points or tips of the spoke are ground down and smoothed over (like what the mechanic suggested to me initially).

One way to make sure that it's a problem with the spokes is to locate where the puncture holes are. If the hole is rim-side, then you know it has something to do with the components. 

2. Replace Your Rim Tape

Since the spokes can poke through the rivets on the inside of the rim, it's a good idea to replace the rim tape that covers the rivets before installing the tube. As time goes by, rim tape will deteriorate and begin to absorb the shape of the rivers, making it easier for sharp parts to poke through. To replace it costs practically nothing and it can make a huge difference in the longevity of your parts, so give your rim a once-over the next time you swap out a tube. 

3. The Tube is Pinched During Re-installation

When reinstalling a new tube, it's easy for the rubber to get pinched inside the tire from hand tools or not enough air to help the tube keep its shape. This results in a slight pinch or fold in the tube that causes it to burst once it's inflated. All you have to do is add a slight amount of air to the tube before placing it into the loose tired. Doing this will allow the tube to form easier inside the tire's housing, which will make the reinstalling to the rim a much simpler process. Also, be sure to use a hand tool only if the tire is extremely taut or difficult to lift over the edge of the rim. In most cases, you can use yours hands to guide the tired back into it's place, and doing so will prevent any pinches occurring inside. 

4. Replace Your Tire

It's easy to think that a tire is safe as long as it has some decent tread left, but in truth, if a tire is worn out, loose, or faded in any areas, it can leave your tube exposed to more hazards. For example, a bike tire has small fibers inside that begin to tear and puncture the tube, combine that with a thinner layer of durability while riding, and you're basically waiting for an accident to happen. That's why simply replacing the whole tire is your best bet to avoid any issues.

One way to check your tire and its resiliency is to take it off the rim and gauge its elasticity. A healthy tire should be somewhat taut while still allowing for a bit of flexibility. A worn out tire will splay open at the folds with loose rubber. If you can turn the tire inside out with a bit of ease, then you're due for a new one. 

5. Avoid Rough Terrain or Debris

Lastly, another reason why you're having so many flat tires could be that you're riding over pavement that has too many cracks, potholes, bumps, or debris. Although the materials are made to withstand pressure, too many impacts or sharp objects (gravel, rocks, glass, nails. etc.) will surely cause damage to the rim and tube, which leads to more blown tubes. It's sort of a no-brainer, but if you keep riding over the same pothole on your morning commute, and suddenly one day your tire bursts, it may be time to find a different route. 

Buy Quality Products and be Safe

As for me, I'm going to REI today with the wheel and I'm going to buy a high-end tube with a brand new tire. Hopefully the repair holds up because my insanely heavy Schwinn road bike is starting to take a toll on my body. 

If you have any thoughts or crazy flat tire stories, we would love to hear them! Please leave a comment below or send us an email! 

Chase MaserComment