Why Do Bicycle Tires Go Flat When Not In Use?

Bicycle tires are essential components of a bicycle, and every bicycle owner’s goal is to have their bicycles in perfect condition.

However, you find it flattened when you don’t use the bike for a while and expect the tires to stay intact.

In addition, it could be confusing since you haven’t ridden the bike, and there shouldn’t be anything wrong with it.

Bicycle tires flatten when not used because the air molecules inside the tire compress and escape through tiny pores in the rubber materials. They also find a way to filter through the gaps between the tire and the rim. This loss over time eventually deflates the tires and results in a flat tire.

Reasons Why Bicycle Tires Go Flat When Not in Use

Bicycle tires deflate when not in use due to the small size of the air molecules that contract and cause tire pressure to drop.

Therefore, when a bike is not used, the tires lose pressure and flatten over time. Here are the main reasons bicycle tires deflate when not in use.

#1. Air Molecules

The air molecules in bicycle tires shrink and slowly filter through the valve seal until the bicycle tire deflates. Your tire loses air with slowly progressive movements.

No matter how tight a seal may be, the air would always find a way to escape.

#2. Heated Air

When you use your bike constantly, the tires heat up, causing the air inside to expand correctly and release less pressure.

As a result, bike tires deflate slower when in use, but if the bike is left stationary for a long time, the air will counteract, lower the pressure and flatten the tire.

#3. Tubeless Tires

The sealant in tubeless tires leaks easily and causes air to leak over time, deflating the tire. A tubeless tire loses air even if it is constantly in use due to heat and wear.

Tubeless tires are famous for their smooth ride, and many riders prefer them, but their main drawback is their tendency to deflate quickly.

You may have to carry a pump around if you settle for tubeless tires.

#4. Cold Weather

Tires tend to deflate during the cold season as the air becomes denser and causes the bicycle’s tire pressure to drop.

Every time the temperature drops 10 ° F, the bike tire loses pressure by one psi. 

It is common knowledge that the tire loses air in cold weather, so you should pay attention to your bike and always use a pressure gauge to check the tire pressure regularly.

In addition, make sure you pump the tire whenever you notice low tire pressure.

#5. Hardened Tire

When you don’t use the tires for a while, they get hard and turn into flat tires.

Therefore, you should ensure you keep your tires in working mode or carry out maintenance from time to time to prevent them from getting hard.

Do Bike Tires Go Flat From Sitting?

The bike tires flatten from sitting for too long because the tire is full of tiny pores and releases air all the time.

The pores are not visible to human eyes but large enough for air to pass through them. Air can also escape through the gap between the tire and the rim.

In addition, when the rubber tires are stationary, the bike’s weight and gravity create a strain. Therefore, a bike left on its wheels would lose pressure faster due to flat spotting.

This is why it is recommended to place the bike upside down to avoid the loss of air pressure.

Can a Bicycle Tire Go Flat Without a Puncture?

Yes, a bicycle tire can deflate without a puncture. Your bike tires don’t necessarily have to have holes as a reason to deflate.

There are many reasons this happens, even if the bike is in constant use.

#1. Damaged Valve

The valve stem is essential for inflating your tire and quickly loses air when it gets damaged. You should completely replace the valve stem if this is the cause of the deflation.

Crushed valve stems, clogged valves, and pinch flattening are common failures that result from the valve stem.

#2. Low or High-Pressure Range

Not getting enough air in or exceeding the recommended air pressure range can cause the tires to deflate.

Conversely, low or high tire pressure can cause bursting, flattening, or rolling of the tire off the rim.

#3. Tire Age

Tires wear with age, thin over time, and loose pressure quickly. A worn tire would flatten without a puncture, which is ideal for replacing it entirely as it would cost you more money to keep repairing it.

Also, constant use of the bicycle would cause the threads in the tire tube to stretch, leading to a drop in pressure over time.

#4. Wheel Problem

A faulty wheel can cause the bike to wobble and lead to a flat tire. A faulty wheel is due to a damaged or loose wheel bearing, axle, and spokes.

Why Do Bike Tires Go Flat When Not in Use?

This is why bike tires deflate when not in use.

#1. Temperature

The air inside the tires is affected by the temperature. Air expands during the hot season and compresses during the cold season.

It means that there will be a reduction in the air in the tire tube during cold climates and causes the tires to deflate.

#2. Wear and Tear

As your bicycle tires age, the material begins to wear out and lose air due to compression when not in use.

#3. Vibrations

Vibrations can damage the tire’s inner tube, causing it to deflate slowly. In addition, vibrations from driving the bike through potholes can leave a side effect on the tires and cause them to flatten when not in use.

#4. Humidity

When air is trapped with water in the inner tube, it leads to rust, damaging the tires over time.

In addition, high tire pressure makes it more difficult for water and air to escape, accelerating the rusting process.

#5. High Pressure

Keeping tires pumped above the maximum range can cause moisture to build up inside the tubes. This moisture eventually causes rust and damages the pipes.

Possible Solutions

The tires deflate from time to time, but there are ways to prevent this, and if it eventually happens, there are simple solutions to get the tires back to working condition when you finally decide to use them.

Here are the solutions to prevent a flat bike tire.

#1. Valve Stem Repair

In case of a damaged valve stem, you should repair it before leaving your bike without using it for a while.

• Locate the valve hole, then poke through the hole with a small object to let the air out.
• Put a tube on edge and pump it until there are no bubbles visible from the inside.
• Pump the tires to the recommended pressure range as indicated on the side of the tire.
• Put the damaged valve stem back in place; use super glue if it doesn’t stay in place.

#2. Tire Pressure

Maintain the tire pressure at the recommended air pressure. Understand the minimum and maximum tire pressure range recommended for each type of bicycle.

Avoid pumping or riding above or below the perfect pressure range.

The ideal tire pressure range for mountain bikes is between 30 and 50 psi, city bikes are between 60 and 80 psi, and road bikes’ tires are between 100 and 140 psi.

The pressure range for each tire is on the side of the tire. It would stop a deflation even if you don’t currently use the bike for a while.

Riding at low pressure can damage the wheels or tire material.

#3. Tire Care

It is essential to constantly inspect your bicycle tires and perform routine maintenance when not in use.

This would keep the bike in perfect working condition. 

• Remove any dirt and debris before they cause problems.
• Always use a pressure gauge to check tire pressure regularly. Refill your tire whenever you notice low tire pressure. Also, check your tires after each ride for sharp objects stuck inside. Objects such as broken glass, nails, and needles can puncture the tires.
• Always check your tires for signs of wear. If you notice any cracks or the threads are out of place, you should completely change the tire.

You can also contact a professional local bike shop to help you keep your tires in shape.

#4. Tube Sealants

It is possible to coat the inside of the pipes with a tube sealant to prevent leaks. Squeeze some sealant through the valve stem, and this would fill any leaks in the pipe.

#5. Puncture-resistant tires and Tubes

Puncture-resistant tires can help to avoid punctures. They are specially designed to withstand punctures.

You can also install a puncture-resistant tube, and this would prevent the tubes from leaking out when pierced by sharp objects. They are thicker and stronger than standard tubes.

#6. New Sealant

If you are using a tubeless tire, you should apply a new sealant every two to three months.

This is because the heat increases the evaporation of the sealants, and the tire material absorbs the sealant faster.

#7. Complete Replacement

If your tires wear beyond repairs, you may want to consider replacing them before letting them sit for a long time.

It would slow down the deflation process. You will have to replace the inner tube if it is damaged beyond repairs.

Conclusion

Bicycle tires would lose their pressure when not used, and you may face the problem of repairing them every time you want to ride them.

However, proper care and precautions can prevent this from happening. With these methods, you can leave your bike unused for as long as you want.

Always contact a professional if you don’t know how to maintain your tires.