Tested: Specialized Command Post Blacklite

Tested: 2011 Command Post Blacklite

Height adjust seatposts are not a new product in the mountain bike industry but only after years of refinement are they now becoming one of the more popular aftermarket mountain bike accessories. Specialized has produced their height adjustable Command Post for a few years now, but it was time for an update with so many more options available.

 The updated Blacklite offers some significant changes from the previous Command Post and also comes in significantly lighter at the same time. Offered in three travel options 125, 100, and 75mm, the Blacklite can now be used by more weight conscious riders who prefer on-the-fly seat height adjustment. Specialized claims weights for the Blacklite are 501g (75mm), 531g (100mm), and 547g (125mm), about 100g lighter than the current Command Post with the 75mm option being the lightest height adjust post currently available.

All three models offer three distinct options for height adjustment:

Level 1 - Climbing position: Normal cross-country seat height for optimal power and leg extension when climbing or riding on smooth surfaces. Level 2 - Cruiser: Dropped down 35mm, this height is intended for technical riding and swoopy trails, to enhance maneuverability while still offering some pedaling efficiency. Level 3 - Descending: Gets the saddle entirely out of the rider’s way for technical steep sections and drops.

Along with significant weight savings the Blacklite features updated seals and bushings, which improve the smoothness of the posts motion while increasing long-term durability.A dual keyway stabilizer prevents unwanted side-to-side play found in past models and creates a more solid feeling seatpost.

 The Inner workings

Height adjustable seatposts may seem like a very simple idea, but the inner workings of these confidence boosters are a little more complicated. All current travel adjust posts have an air spring system that returns the post to its desired height, but what differs between manufacturers is the system that holds the seat in to place. For this, Specialized chose a mechanical system for its simplicity, durability, and serviceability for riders and shops when compared to hydraulic designs.

The Command Post BlackLite, like other cable remote systems, utilizes a standard derailleur cable to adjust height. The cable releases a mechanical collet, allowing the post to slide up and down. The rider’s weight drops the post, and an adjustable air spring returns it. Once the lever is released, the collet locks into one of three machined height slots, securing the post in place in one of its three positions.

Specialized’s new seals provide ample protection from the elements no matter where you live. It features a double lip X-Ring seal and the previously mentioned dual key way system that eliminates side-to-side play. The post feels amazingly solid for a height adjust post with very little flex or movement.

One drawback we found was with the posts return speed, which is easily adjustable via a Schrader valve in the bottom of the post, but there seems to be very little variation in speeds. Adding or subtracting some air from the system is easy enough; less air equals a slower return and added pressure for a quicker return.

But with only 8psi, the post still returned with undersireable speed, although less violently than with higher pressures. It’s a little scary having your saddle launching at your backside like a spring loaded missile. We quickly learned to stay clear - See video below.

The biggest selling feature with this post is the travel options for maximum weight savings, on the light end with 75mm of drop, XC riders can still gain the benefits from an adjustable post with very little added weight. Three travel options is a nice feature for the weight conscious, but may make the choice difficult for the indecisive.

Utilizing a derailleur cable for the remote makes the remote extremely serviceable and Specialized tells us that the internals are also easily serviced, but require a little more indepth mechanical knowledge.

The Blacklite should be available for aftermarket purchase by the end of June, 2011 and Specialized will be stocking the post on many 2012 bikes.  Overall, the mechanical design behind the Blacklite is solid. The post does its job, is extremely easy to set up, and is engineered to standards you’d expect from Specialized.

The first video shows the return rate with 25psi in the post and the second is at 5psi.