Sisärenkaasta

Sisärenkaasta is a Finnish term that translates to "inner tube" in English. It refers to an inflatable ring typically made of rubber that is placed inside a tire. The primary function of an inner tube is to hold air and maintain the tire's pressure, which is essential for its performance and the smooth operation of a vehicle.

Inner tubes are commonly found in bicycles, motorcycles, and some older or specialized automobiles. They were once a standard component in all pneumatic tires but have largely been replaced by tubeless tire technology in modern passenger cars. Tubeless tires have an airtight bead that seals directly against the wheel rim, eliminating the need for a separate inner tube.

The advantages of inner tubes include their ease of repair. A punctured inner tube can often be patched, making it a cost-effective solution. However, they can also be a point of failure, as leaks can occur at the valve stem or through small punctures in the tube itself. Additionally, inner tubes can sometimes shift within the tire, leading to imbalance or damage. The development of tubeless tires has offered improved puncture resistance and better air retention, contributing to their widespread adoption.