sync.on('update', function(data) {
   var curRatios = flex._ratios.state,
     pos = (data.position/100)/100,
     ratios = [Math.min(2, curRatios[0] + pos), Math.max(1, curRatios[1] - pos)];

  if(data.position > 0) {
    flex.setRatios(ratios);
  }
});
sync.on('end', function() {
  flex.setRatios(defaultRatio, {curve: Easing.outQuad, duration: 300});
});