Toyo RIR wear n tear

[KARTer]

My current RIR seems to stop wearing ie the thread groove/depth seem to stay the same for the past 2 years!! ..... i bought them 2nd hand (previous owner changed car after using these RIR for 2-3 months before he sold them to me, tyres have never been tracked before and after I bought them)

 

My 'theory' why they stop wearing: rubber hardened when tyres reached around 1 year old and therefore hardly wear out.... the tyres dont show any sign of minor cracks, so are they safe enough for dialy normal driving in the dry? ...... the grip seems ok for normal use.

 

Thank you advance for any bro's advice

 

(my yearly mileage is about 20k km)

[Dreamer143]

Hard Tires usually have more resistance to wear and tear but the vehicle will become more jerky & bumpy due to hard tires and mechanical maintenance cost rises due to unnecessary bumps.