What does FR on tires mean?

[McRuby]

Tire FR represents a tire with reinforced sidewalls and rim protection, featuring a protruding section near the bead area made of rigid rubber. Tires are typically mounted on metal rims to support the vehicle body, absorb external shocks, maintain contact with the road surface, and ensure driving performance. Tires operate under complex and demanding conditions, enduring various deformations, loads, forces, and extreme temperatures during use. Therefore, they must possess high load-bearing capacity, traction performance, and shock absorption capabilities. The service life of tires is generally 3 to 5 years or 60,000 to 100,000 kilometers. Beyond this period, tires begin to age, losing their elasticity. Continued use of aged tires may cause tread deformation and increase the risk of blowouts.