What is the 3% rule for tires?
The 3% rule states that when replacing tires, the new tire’s diameter should not differ from the original by more than 3%. This guideline helps maintain proper vehicle performance, safety system functionality, and speedometer accuracy. The 105% rule says that the external rim width of your wheel should be at least 105% of your tire’s actual measured width. This ratio allows the airflow to remain attached as it moves from the tire onto the rim, reducing drag and making your bike more aerodynamic.Use Tread Wear Indicator (TWI) The legal limit of 1. Remember: – Check your tread depth on all four tyres – Check the inner, centre and outer. Tread depth In order to remain legal, tyres must meet the minimum legal tread depth, which is 1. This 1.