Causes of Teared tyres?

[Daleyg3]

Afternoon everyone,

last night I was fitting my new Rockstar Pro hubs to my Nompa and noticed a tear in the side of one of my Trampa tread tyres, which had caused the inner tube to be nearly bulging out/escape.. I've not had this happen before to any tyres and thought the thicker Trampa Treads would last a long time (only had them 6 months).

Anyone think of a possible cause? The max PSI they've ever been at was 50 and they've never had a puncture.

[barxx]

stones are pretty good at tearing a sidewall, or tree roots only takes a small nick to set it off. especially as we do ride at pretty high psi's