I hear you, I'm 175lbs in my skivvies, I'll check the conversion from kilos to pounds. I read a post in one of the TH forums that stated there was an issue with the gold bird spring not being strong enough, but it's bound to happen, nothing is failsafe or perfect. There may be a fair amount of variables that apply to all ascension/descension devices. Take Care and hope to chat again, soon.
Respectfully; Dave R