Store tyres separately. I have tyres from the 90s that are fine. But tyres from the 2000s started melting after ~10 years. I don’t know a lot about rubber but I

Store tyres separately. I have tyres from the 90s that are fine. But tyres from the 2000s started melting after ~10 years. I don’t know a lot about rubber but I guess they switched from natural rubber to petroleum-based rubber. Problem with the melty tyres is that they also damage any pieces they’re touching, so it can ruin a set.