There's a guy who brings a bike into the shop for repair quite often, as he is a big big guy as well. I mean I am 220-230 on average lately, but I have never FOLDED a big chainring like this guy did last time he brought his bike in. He said all I did was jump up on the bike with one foot on the pedal, and used my weight to propel myself from a dead stop. This should give you an idea of what stress a chain is put up against while shifting under heavy load. Go single speed and use a 1/8" chain if you want to mash that hard?,,,,BD