Check out this interesting new pulley / counterweight kit that mounts to Varavon Sliders. The counterweight allows you to position your slider in slanted angles so that you can lift the camera with ease or to keep your camera from crashing down. A plate mounts to the slider carrier, and the counterweight is hung through a wire and pulley system.
Your counterweights are just common water bottles, which means you don't have to travel with heavy weights. Just pick up a few when you arrive at your destination.
The kit is shown to work with a variety of Varavon sliders including the Slidecam Lite or the Slidecam S. Take a closer look and notice the basic screw mount, which I'm guessing could even work with any Cinevate, Konova, or other aftermarket slider as well. The Varavon Slider Counterweight Kit starts under $50 bucks via eBay (click here).
Varavon Slider Balance Counterweight Pulley Kit