Smooth scroll page

Question

I would like a smooth scroll wheel.

I found this smooth scroll script: http://codepen.io/JsGists/pen/xRmRyN

It work's fine but there is a conflict with another jquery script: http://pixelcog.github.io/parallax.js/

If I use Parallax.js the smooth scroll doesn't work. If I remove the Parallax.js, the smooth scroll works.

[MY JSFIDDLE][1]

HTML :

<main>
  <span class="bc">  </span> 
  <span class="bc">  </span> 
  <span class="bc">  </span> 
  <span class="bc">  </span> 
  <span class="bc">  </span> 
</main>

CSS :

span {
  height:200px;
  width:400px;
  margin:50px;
  display:block;
}

body {

  height:1000px;
  overflow:auto;
  -webkit-overflow-scrolling: touch;
  position:relative;
}

main {
  display: block;
  width: 100%;
}

.parallax-slider{
  transition:1.5s ease-out transform;
}
.parallax-mirror.hovered .parallax-slider,.parallax-slider:hover,.parallax-mirror:hover .parallax-slider{
   transform:scale(1.2)!important;
}