Why Does My Bike Tire Keep Going Flat?

Bike Tire for Puncture ResistanceOne of the most frustrating problems when cycling can be when you get a flat tire; it always seems to be at the most inconvenient time. When you go to jump on your bike, you expect it to be ready to go – what you don’t expect is to have to waste time changing your tire.

Unfortunately, it is inevitable that you will experience a flat tire at some stage in your cycling career, therefore, it is important that you ensure you are well prepared to, firstly, identify the reason your tire is flat and, secondly, have the knowledge and tools necessary to do a tire change.

If you want to save time and money, it is recommended that you learn to change your own inner tubes. It is also advisable that you make sure you have plenty of spare inner tubes in case of emergencies or if you are not within a reasonable distance of a bike store to get it repaired. (I recommend these ones and Amazon has them for a good price normally)

Most inner tubes are made from rubber and inflate with air, therefore, anything sharp, including thorns, glass, rocks or nails, can cause damage to the inner tube and allow the air to leak out. Depending on the severity of the damage, your tire may deflate rapidly or slowly over time; either way, you will not be able to ride on a deflated tire without causing serious damage to your rim and or tire, potentially costing you a fortune to repair or replace in the future.

Surprisingly, there are a number of reasons your tire can go flat. Some of the most common reasons your tire will become flat include:

  • Punctures by a sharp object
  • Failure or damage to the valve stem
  • Rubbed or ripped tire
  • Over pumped tires (blowouts)
  • Road hazards (potholes, debris)
  • Uninspected damage
  • Rim damage (tubeless tires)
  • Inner Tube Pinching
  • Slow leaks
  • Pinch Flat (snake bite)
  • Burping (loss of air in a tubeless tire when its seal with the rim is compromised)
  • Tire quality and/or wear
  • Inner Tube quality and/or wear
  • Damaged tire liner
  • Damaged rim tape (high-pressure tires)
  • Sharp edges from the rim drilling (spoke holes)

Things you could check if you find you have a flat tire

– Sharp edges on the rim of your wheel

– Tire wear- if your tires are low in tread or they are weathered, it is more likely you will get frequent punctures. Also, check if your tread is suited to the terrain and/or style of riding you are currently doing; It is more idealistic to use the correct tire and tread for the style of riding you are planning to do in order to decrease the risk of a puncture.

– Tube wear- if tubes have been left in the tire for some time or they have been exposed to rough weather, they are more likely to be susceptible to punctures. For example, tires exposed to extreme heat will be subject to expansion, resulting in a rapid deterioration of the rubber quality and a subsequent increase in puncture frequency.

– If you find a foreign object embedded in your tire, use your fingers and run them along the inside of the tire. You should be able to feel if any objects have become stuck inside and are causing the damage to the inner tube.

– The valve is another area that can commonly cause a flat tire. There are generally two different types of valves that are commonly found on tubes. Road bikes are more likely to have the Presta valve, or, if you are mountain bike rider, your tire is more likely to have an American valve (car valve). If you have a faulty valve, your inner tube will not hold air. If this is the case, it is best to completely replace the inner tube with a new one.

– Self-inflicted damage – when changing your tube, ensure you are following the correct procedure and not inadvertently damaging the tube for it to once again fail and deflate. Pinching the tube is common in novice riders or mechanics, a mistake that will leave you, yet again, with a deflated tire. Ensuring you are using the correct tools when changing the tube, especially tire levers, can help prevent tire pinching. Another trick to avoid this issue is to slightly inflate the tube prior to installation making sure the tube is tucked inside the tire neatly, with no twists or bends. Then, replace the tire edges inside the rim. You can also slightly push the valve back up into the tire, then inflate the tube fully. This will allow the tire to sit evenly and correctly, avoiding bulges in the tire that can lead to punctures.

– Tire pressure and Blow Outs – when inflating a tube, you need to ensure that the pressure you are inflating it to is the correct amount for that make – you will find the tyre pressure recommended printed on the side of the tire. Running the pressure at an increased inflation will cause blowouts and punctures. If your tire is under the recommended pressure, it can cause a pinched flat, or roll the tire off the rim, making you work harder during your ride and inevitably leading to poor braking control.

– Tire and Tube Quality- When purchasing tubes and tires, ensure you buy a reputable brand. Although purchasing a cheaper tube or tire will save you money in the short term, you will ultimately be left making up the cost when you have to continually purchase replacements. Go for well-known, reliable inner tube and tires brands such as Kenda, Continental, Rocket, Maxxis or Vittoria. These companies have a solid reputation for manufacturing reliable inner tubes for all wheel sizes and cycling applications.

Preventative measures

– Once you have repaired a puncture, it is important to put some preventative measures in place to minimize your chances of re-puncturing your inner tube. There are a number of simple steps you can take to maintain your tire quality and limit the chances of punctures whilst you’re on a ride.

– Firstly, tire liners are a good method of adding some extra protection around the inner tube. My favorite tire liner is Mr Tuffy; these are re-useable polyurethane strips that form a protective barrier along the inside of the tire. This protects the inner tube from sharp objects. Mr Tuffy liners are lighter than self-sealing and thorn resistant inner tubes and they are also more effective against a wider variety of road hazards. They are easily installed with no sealant required. (You can get them here on Amazon – great reviews!)

– Depending on the width of your tire, you will need to match the size of your inner tube to ensure you have adequate tube protection. For example, if you purchase a 25mm wide tyre, but use a 23mm wide inner tube, the rubber of the inner tube will be spread too thin, increasing your chances of a puncture. Also, be aware of a race light inner tubes. While they are lighter, they do not provide the same protection as a tube made of thicker butyl rubber.

– Pay attention to where you cycle, main traffic lanes are usually free of glass and other debris that may cause a flat. Cyclists have a tendency to cycle close to the shoulder were glass and other dangerous objects usually pile up. Avoid potholes and manholes when possible and pay attention to what is ahead and you. When cycling with friends or in a group, ensure the front riders notify the other cyclists of any hazards that may be in the way.

– Choosing a good quality tire can also prevent inner tube punctures. The Continental Gatorskin, mentioned here in our review article, is known to be the market leader amongst road bikers for puncture protection and great service life. The excellent puncture protection afforded by the Gatorskin is due to the PolyX Breaker puncture protection insert. This technology offers an extremely long service life through wear-optimized tread compound.

Tires with DuraSkin have maximum sidewall protection and are able to roll with the punctures. This allows cyclists to have confidence whilst cycling in the harshest conditions. (We have an article here about the best tires for puncture resistance)

While there are numerous reasons you can have a flat tire, there are also a number of methods you can use to ensure you minimize your chances of getting a puncture. Be sure to use the aforementioned preventative measures to protect your bicycle against flats.