Specialized Command Post BlackLite Review

The Details

The BlackLite is a mechanically operated, air sprung, dropper post that features three height positions: fully dropped (either 75mm, 100mm, or 125mm depending on the model), a 35mm drop cruiser setting, and full extended. Internally, it employs an expanding collet design that locks it into each position. The remote lever pulls on the spring loaded activation arm on the post's head, which in turn raises an aluminum plunger within the post. A secondary internal cable is attached to the end of the plunger, which itself is clamped in place at the collet mechanism. Hit the lever and the internal cable is pulled, which in turn raises a wedge within the expanding collet, allowing it to relax inwards and move from the groove that it's currently in. Releasing the remote lever allows the spring loaded wedge to return back down into the collet, forcing it to expand out into one of the three grooves machined into the circumference of the post's inner wall and locking the post in place.


While the mechanical collet design may sound complicated, Specialized is confident that the layout is more robust than a hydraulic system, saying that the issue with hydraulic posts is that the ''seatpost shaft is sitting on a slug of oil which is constantly building pressure. Oil is incompressible, so to relieve the pressure o-rings bulge or fail, resulting in inconsistent saddle position, among other problems''. One of the major upsides to the BlackLite's design is that, barring a cataclysmic failure, the post should still be able to be locked in place if there is an issue with the air spring or remote, allowing you to pedal out of the bush with a proper saddle height.


Two bushings are employed, with a split, floating bushing at the bottom of the inner tube, and a stationary bushing at the top of the post. Dual brass keys are set into the upper tube, each one following a groove machined into the wall of the outer tube, that keep the post wiggle free. A triple-lip wiper seal is employed to keep mother nature out of the post's inner workings, and the saddle is held in place with a single, opposing bolt rail clamp atop the post's bonded in place head. The BlackLite's remote is thumb operated, and has been designed to replace the inboard lock-on clamp of a Specialized grip (we discovered that it also slipped onto some others as well, but not ODI lock-on models). It isn't hinged, meaning that you'll have to slide the grip off of the bar to install or remove it, and it pulls on a standard shift cable to activate the post.

Our 125mm drop, 405mm long test model features a minimum insertion to saddle rail clamp height of 325mm, and measures 195mm from maximum insertion (the bottom of the top cap) to the saddle rail clamp. Both numbers were measured with the post at full height.




Installation and Setup

The BlackLite is relatively straightforward to set up, requiring only 2mm, 3mm and 5mm hex keys for the cable clamp, remote clamp and the saddle rail clamp, as well as a shock pump to set the post's air pressure correctly. Check the seat post's air pressure before running the cable and housing - it makes more sense to do it now, before the cable is clamped in place, even if Specialized has built in a cable quick release. The maximum pressure rating is 40psi, which will result in a very quick rebound speed. Dropping it down to under 30 will slow the return speed, something that many riders will likely end up doing. Be sure to confirm the air pressure with the post at full extension otherwise you'll get an artificially high reading.


Set the post to the correct saddle height before stringing the cable and housing, otherwise you mind find yourself with either a too short or too long of a line after you've set your seat to the right height. Next, we loosened the saddle clamp enough to allow us to rotate the saddle back so it pointed straight up, giving us access to the cable clamp barrel on the activation arm. The post's housing stops, on both the remote and the head, only accept 4mm housing and end caps, and the BlackLite comes from Specialized with a length of stiff, 4mm shift housing in order to limit compression when the remote is pushed. A standard shift cable is used to activate the post, with it also being included in the kit. As with any cable operated system, be it a dropper post or your rear derailleur, you need to take the time to ensure that the housing travels in the smoothest possible route, as well as being long enough to not pull on the cable when turning the bar extremely sharp for a tight turn. Slide the cable through the remote and the supplied metal noodle, as well as the in-line barrel adjuster, and pull it snug before clamping it in place.


You may have to pull slightly more cable through the clamp after pushing on the remote firmly a few times in order to take up the slack from the housing ends settling in. Alternately, you can use the supplied in-line barrel adjuster, although this is best left for smaller cable tension adjustments. We found that the BlackLite is very sensitive to cable tension, meaning that you'll likely have to make a few adjustments after letting the new cable and housing stretch and settle in. Too much cable tension and you'll likely have a hard time locking the post into position, and it could also have a small amount of play, or rattle, when at full extension. Too little cable tension and the post won't drop when you want it to. It only took a few minutes to figure out exactly how much tension was required, with the in-line barrel adjuster making it quite easy to set up correctly. Trim the cable, rotate the saddle back down to the correct angle and torque it to the required 120in/lb, and you're ready to hit the trail.


Performance

You may remember from our review of the original Command Post that we had a major gripe with its remote lever - it was flimsy and had lever pivot play from day one. Specialized also knew that the old post's remote was a weak point and, kudos to them as they remedied the issue. The BlackLite's remote is close to being the most ergonomic that we've ever used, whether we mounted it in place of the lock-on clamp on a Specialized grip, or just butted it right up against the grip itself. The thumb paddle has been positioned in a reasonable place, although riders with small hands may find it a bit of a reach, and the lever pivot provides enough leverage to easily overcome the return spring on the remote and the post's head. Equally important, it is much sturdier than the old design, with very little pivot play. The metal noodle that Specialized includes to route the cable out from the remote is nice because it eliminates either a tight bend in the housing or a large housing loop off the front of your bike, but it also may not play nice with some brake lever setups, forcing it into a weird position.


Every rider who used the BlackLite was taken aback by just how fast the post rebounded to full height, with the loud top out clang also adding to the scene. A game would often break out of riders trying to catch the small pebbles being launched into the air when placed atop the lowered saddle before hitting the remote. Although the the post's undamped rebound speed does look and sound excessive, we actually never experienced any of the issues that one might associate with the seat returning to full height at the speed of sound. In fact, we came to like the BlackLite's fast rebound speed that put the saddle back up to full height nearly instantaneously, a useful attribute when on sharply rolling terrain. That same fast rebound made hitting the 35mm drop postion tricky from the fully lowered setting, though. Even after countless miles, we resorted to simply hitting the remote lever and stopping the saddle with our ass, allowing us to lock it into the cruiser position. We had a much easer time finding the 35mm drop position when lowering the saddle from full height. We also grew to prefer the post's somewhat loud top out sound because it let us know, without a doubt, when the saddle was at full height. This was especially appreciated after using a nearly silent dropper post, not to mention one with quite a slow return speed, that left us wondering if it was actually at full height after hitting the remote lever.


The low air pressure of 40psi, together with the large volume of the air chamber, means that you're not fighting much resistance when using your body weight to lower the saddle. Unlike some other designs, it was easy to get full travel out of the BlackLite. There is also close to zero saddle play, even when trying to move the nose of the seat side to side. This is down to the BlackLite's locking collet mechanism that firmly grips into the machined grooves at each position, as well as tight bushing and key tolerances. The same can be said after a full season of abuse - there is as little play as when the BlackLite came out of the box. Impressive.

The post's middle, 35mm drop cruiser position makes a lot of sense on rolling terrain, and even on steep and technical climbs where a slightly lower seat height can help with the confidence, but we sometimes found ourselves wanting it to be just a touch lower. This feeling stems from using an infinitely adjustable post during the same time period, allowing us to choose the exact seat height that we wanted for a given situation. We can see a lot of riders being happy with the BlackLite's three set positions, but those who are coming off an infinitely adjustable post may find it a bit limiting.


Issues

We've put over a full year's worth of saddle time on our BlackLite, including everything from cross-country stage races, one day enduro events, and a wet and cold Winter riding season here in B.C., resulting in the BlackLite being one of our most thoroughly tested products. Barring the odd cable replacement, something we view as routine given our wet riding environment, the BlackLite remained trouble free for the large majority of our time on it. Alas, we ultimately did experience a loss of air pressure due to a compromised o-ring at the bottom of the post, rendering the BlackLite unable to return to full mast without manually raising it by hand. The offending .25¢ bit of rubber was easy to replace, but it also brought another issue to light when we disassembled the post for the repair: a section of the locking collet mechanism managed to break itself off its home and was left to rattle around inside the bottom of the post. Keeping in mind that we gave the BlackLite literally zero love during our time on it, which was something of around two hundred rides over more than a full year, and that the collet mechanism is actually a wear item, we can't fault the post too much. It is also important to note that the post functioned just fine on the trail with the damaged collet, working as if it never occurred. We don't recommend riding the post in such a state, obviously, but it highlights the BlackLite's mechanical design that will likely allow you to at least raise the saddle to full height and pedal out of the bush if it does have a mechanical. This was put in focus when we originally lost air pressure and had to manually raise the post before locking it into place, not something that can be done on a post with hydraulic internals.

Specialized went with a full mechanical design because they feel that it is more reliable than what a hydraulic system can offer, and they may be correct on that front - the BlackLite worked fine even with the broken collet - but going mechanical has its own challenges. As with any cable actuated post, which is nearly every option on the market, activation will deteriorate once the cable becomes contaminated. This may not be an issue for those who live in drier climates, but it means that the trigger becomes progressively harder to push if you consistently ride in wet conditions. Replacing the post's activation cable is quick and easy, but the cable itself will always be a weak point in regards to nasty riding conditions.

We also have to question the head's saddle clamp, a single bolt design that has been shown to not hold the saddle firmly enough under hard use. Our saddle rotated multiple times, just as on any other post that uses a similar clamp. Finally, there are certainly riders out there who are always going to be spooked by the BlackLite's fast rebound speed. Lowering the air pressure slightly will slow this down, as will using a thicker grease within the post, but it is likely still going to return to full height faster than some other options on the market. We view this as a plus, but some other riders who used the BlackLite weren't a fan.

Pinkbike's take:

www.specialized.com