How Tubeless Tires Work

Experienced cyclist turned writer with 7+ years working in bike shops, overseeing retail and workshop operations.

A tubeless tire system is an innovative approach to bicycle tires that eliminates the need for an inner tube. Instead, the tire and rim work together to create an airtight seal, allowing the tire to hold air without using an inner tube. 

Tubeless systems offer several advantages over traditional tires with inner tubes, such as improved puncture resistance, running lower tire pressure for better traction and comfort, and self-sealing properties for punctures. 

The article discusses a tubeless tire system’s main components, features, and functions.

Tubeless-ready tires

Tubeless-ready tires are specifically engineered for use in a tubeless tire system. They differ from traditional tires in several ways;

  • Airtight sidewalls. The sidewalls of tubeless-ready tires are airtight, preventing air from escaping through the tire’s casing. This is done through the use of specific materials and manufacturing techniques, such as additional layers of rubber or airtight coatings.
  • Robust bead. The bead of a tubeless-ready tire is more robust and less elastic than a traditional tire, allowing it to maintain a secure, airtight connection with the rim. This feature is essential for the proper functioning of the tubeless system, as it prevents air from leaking out at the tire-rim interface.
More reading : What Does Tubeless-Ready Means?

Tubeless-ready rims

Tubeless-ready rims are designed to work seamlessly with tubeless-ready tires, ensuring an airtight seal and facilitating easy tire installation and removal. 

The key features include;

  • Central channel. The rim bed of a tubeless-ready rim features a central channel that allows the tire’s bead to sit lower during installation, making it easier to mount and dismount the tire. Once the tire is inflated, the bead moves out of the central channel and onto the raised shoulders on either side, creating a tight seal.
  • Raised shoulders. Tubeless-ready rims have raised shoulders on either side of the central channel, which locks the tire’s bead into place when the tire is inflated. This design helps maintain the airtight seal between the tire and rim.

Tubeless rim tape

Tubeless rim tape is essential to a tubeless tire system, creating a smooth, airtight surface on the rim bed. 

This adhesive tape is applied directly to the rim bed, covering the spoke holes and any irregularities that could cause air leaks. 

When selecting tubeless rim tape, it is important to choose a tape width that is 3 to 5mm wider than the rim’s internal width, ensuring complete coverage and optimal performance.

Tubeless valve

The tubeless valve is a specially designed valve that serves two main functions in a tubeless tire system;

  • Airtight seal. The tubeless valve is designed to create an airtight seal with the rim at the valve hole, preventing air leaks at this critical interface.
  • Air and sealant Introduction. The tubeless valve allows air and tire sealant into the tire. The valve core can be removed to inject sealant, and the valve is designed to accommodate pumps and air compressors for easy inflation.

Tire sealant

The tire sealant is a liquid substance added to the inside of a tubeless tire to provide a self-sealing effect in small punctures.

The sealant coats the tire’s interior and quickly fills the hole when a puncture occurs, preventing significant air loss. The amount of sealant used varies depending on tire size and manufacturer recommendations but typically ranges from 2 to 4 ounces (60 to 120ml) per tire.

Tire sealants generally comprise a liquid base, such as latex or synthetic latex, along with solid particles or fibers that help to plug punctures. It is important to periodically check the sealant level and consistency, as the liquid component can evaporate over time, leaving the solid particles behind. 

Depending on the sealant type and environmental conditions, the sealant may need to be topped up or replaced every few months.

By understanding the main components of a tubeless tire system, such as tubeless-ready tires and rims, tubeless rim tape, tubeless valves, and tire sealant, you can better appreciate the benefits of this innovative approach to bicycle tires and optimize their riding experience.

Bernard Lu at Mr.Mamil

Bernard Lu has 7+ years of experience working in a bicycle shop, overseeing the retail and workshop operations. He’s a qualified bicycle mechanic who understands a cyclist’s needs and speaks the same cycling lingo.

If you meet him at the cafe, he will happily talk to you for hours about all the intricacies of bikes and cycling tech. Just buy him a coffee next time you see him.