Susan BX is the same as Susan B, but with a shock fork. It's a great way to absorb shock from potholes, ruts and other road furniture that gets in the way.

We tailor the size components on all of bikes to match the size of the rider, so you'll be as efficient as possible. You'll notice that we also vary the wheel sizes with the bike size. By doing this, we're able to make sure the reach to the handlebars, the relation of the saddle to the handlebars and the handling of the bike is correct. We're the only manufacturer who does this.

http://www.terrybicycles.com/Bicycles/Hybrid/Susan-B-X