have less range of movement than many other CV styles. What they lack in range though they make up for with a simple, cost-effective design.
In a tripod design the input shaft is attached to what is called the spider, or tripod. This looks like a circle with three circles mounted on roller bearings surrounding it. The differential will have a cup of some kind that accepts the tripod (these can be open or closed). The rollers allow the tripod to slide back and forth.
This design accounts for the reduced range of motion. In many ways, a tripod looks the most like a universal joint. But, unlike a universal joint, the tripod joint can accept a greater range of travel. While the max angular articulation of a tripod joint is 26 degrees (still a lot more than a U-joint), it can travel 50 mm.