if they look ok, they probably are. I use some high rollers that I bought in 2006 whenever i’m doing anything where a big tyre might be fun. I only recently swapped some tioga factory XC’s I’d had since the mid 90’s (for a BMX)
Anyone got any thoughts on using old mountain bike tyres? I have some IRC Kujo tyres that must be over eight years old and probably not used for five years that I fancy sticking on for a change. They look alright and will have new inner tubes but any risk on perishing?