Tyres- What age would you change tyre(s) at? AND....120 section on the front?

[Disorderlypunk]

Sorry if you know this already, but if you look at the sidewall of the tyre you should find a four digit number stamped on it's own and this will tell when the tyre was made. For example 1016 would mean it was made in the tenth week of 2016, 4312 = 43rd week of 2012, etc.

didnt know that - turned my last from tyre into a table and turns out that was made in 2013 so no wonder it was cracked