The latest craze to sweep the nation? Maybe not, but "dropper seat posts" are definitely becoming more common. Once thought of as being in the realm of only the most "extreme" mountain bikers, they are now finding their way on to more and more trail bikes, and even some XC types are taking a look at what a "dropper post" could do for them.
Of course, these are nothing new, or at least, the concept isn't. Once upon a time, the idea of dropping your seat post for technical descents was actually quite common. In fact, a slick little gizmo was developed early on during mountain biking's early "modern era" that you could use "on the fly", just like these fancy-schmancy dropper posts of today. It was called the "Hite Rite", and was pretty simple in its design.
Basically, it was a fancy spring that grasped the seat post on one end, and was attached to the binder bolt on the other end. One simply had to open the quick release on the seat binder, use your body weight to depress the post into the frame, and lock the quick release back down at the desired height. When you wanted the seat back to full height, you simply got your weight off the saddle, released the quick release again, which allowed the spring to push the saddle back up, close the quick release, and you were back to full height once again.
Of course, it all depended upon whether or not your seat post and frame fit well together, allowing for free movement of the post when the quick release was opened. Hite Rite seat locating springs weren't without other draw backs. Longer seat post extensions that became popular with designers and riders in the 90's pretty much put the Hite Rite at odds with practical usage for mountain bikes since the range of drop was limited on the design. It wouldn't be for another ten years that dropper designs started to resurface that used a telescopic design instead of the spring the Hite Rite was based upon. These telescopic designs, while being more complex, offered a much wider range of "drop".
The Specialized Blacklite Command Post is one of the newest designs out, featuring lighter weight, and better performance promises over other telescopic seat post designs. We'll see, as one is on test now at The Cyclistsite.com.