Trends in mountain biking: Adjustable Seatposts
One of the relatively new innovations in the mountain bike world, and arguably one of the best riding accessories/upgrades (especially when it comes to more aggressive styles of riding) is the adjustable seat post.
I have a KS i950 on my Marin. One of the best riding upgrades I made.
An adjustable seatpost allows you to change seatpost height “on the fly” without having to dismount and loosen/tighten a quick release lever, thus enabling the rider to quicly get in the most optimal riding position depending on the trail sections about to be tackled. Drop the saddle all the way down to get behind it and shift your center of gravity backwards on steep sections, or raise it to maximum extension (set according to your own bike fit measurment) for optimal climbing efficieny, or even set it midway through to cruise long flat sections in comfort between vigorous efforts on steep climbs and descents. All with a flick of a switch or a pull on a lever.
A remote-actuated Crank Brothers Joplin 4 (left) vs. a lever-actuated Crank Bothers Joplin 4.
There is already a smattering of seatposts on the market, varying in technology from mechanical to hydraulic mechanisms (Gravity Dropper and RASE are mechanical, while the KS i950 and CB Joplin shown in the pictures above are hydraulic, for example), different remote/lever actuation methods (an under-the-saddle lever, cable-actuated remote or hydraulic-actuated remote), varying drop styles (infinite adjustment, where the post can be dropped at any point along its travel, or multiple preset saddle positions like the Specialized Command Post).
The Rock Shox Reverb adjustable seatpost uses hydraulic remote actuation system.
The technology is still being refined by manufacturers. Newer posts have better sealing technologies, smoother actuation mechanisms, and the weights are getting lighter every year, but there is still a lot of room for improvement, especially in maintenance intervals and weights. These posts are still relatively heavy at 500+ grams, and most of them need frequent service, especially in harsh weather conditions. This summer while riding in wet/muddy conditions in the Alps, my KSi950 stopped working completely and I had to strip it down and do a service to get it functioning again.
The Specialized Command Post has a mechanical 3-position locking height adjustment.
Many bike manufacturers now incorporate built-in cable guides for adjustable seatposts on many of their high end mountain bikes. Some, like Trek, have come up with clever internal cable routing for the remote cables, which gives the frame a much cleaner look and when using an adjustable seatpost. More importantly, as the technology becomes more mainstream in the mountain bike world, adjustable posts are becoming cheaper.
In a future post we will compare different adjustable seatpost specs side-by-side so that you can easily make a choice if you’re in the market for one.
