What is the purpose of enforcing a diameter difference limit on dual tires?

• A. To improve ride comfort
• B. To maintain stability and even load distribution
• C. To reduce cost
• D. To enhance acceleration

Answer: (B)

Keeping dual tires on the same axle matching in diameter ensures both tires roll at the same rate and share the load evenly. When the tires have different diameters, their circumferences differ, so they would travel different distances per rotation. Since the axle drives both wheels together, the larger-diameter tire would effectively force the smaller one to slip or scrub, leading to unstable handling, especially during turns or braking, and uneven wear. This balance is crucial for stability, predictability, and tire longevity, as loads and traction are more evenly distributed across both tires. While ride feel and cost can be affected by tire size, the primary purpose of the diameter limit is to maintain stable handling and even load distribution.