9Point8 Pulse Dropper Post - Review

There are a good number of dropper posts on the market these days, with many different designs to choose from that all look to do similar things in the end, but that hasn't stopped 9Point8 from designing their own version that they say offers a different take on getting your seat out of the way.




Construction


The two-stage valve isn't the only clever bit hidden within the Pulse's black aluminum body - the 9Point8 also employs a cunning brass key-way design that they say greatly reduces rotational play between the outer body and the stanchion tube that might otherwise increase over time. Brass keys aren't anything new of course, and they are used in most dropper posts, but 9Point8's are different in two ways: each of the three keys is actually split in half and hollow, with a small spring between each portion; and they also sport a unique bullet shape that corresponds with their homes machined into the bottom of the Pulse's stanchion tube. The idea is to allow the keys to self-adjust in length, thanks to the spring between each half, as both them and their channels wear, thereby lessening the amount of free play that might develop over the long haul.


Return speed can be adjusted by raising or lowering the pressure of the air spring with a standard shock pump that threads onto an air valve located at the bottom of the Pulse. 9Point8 ships the post with a nitrogen charge of 200 PSI, and they recommend between 150 and 250 PSI depending on your needs and the conditions. For example, extremely cold temperatures may mean that you'll have to run a higher pressure in order for the post to rebound at regular speeds. Despite the nitrogen charge that it comes stock from 9Point8 with, using standard air will have zero affect on its performance.


The Pulse's head uses a sturdy looking design that separates fore/aft and seat angle adjustments, a smart layout that means removing your seat for whatever reason won't see you starting from scratch in regards to your preferred seat angle. The opposing horizontal rail clamp bolts are tightened down with a 4mm hex tool, while a set of inline vertical bolts thread into replaceable steel barrels and adjust saddle angle. These inline bolts require a 3mm hex tool, which is slightly smaller than what the rail clamp bolts ask for, and the cable clamp bolt on the actuation arm requires yet a different 2.5mm hex key. 9Point8 have also gone to great lengths to meet the needs of different riders who may require either an in-line or setback seating position, with a $35 USD conversion kit available that consists of an interchangeable rail clamp assembly that gives 25mm of setback.



Installation

The Pulse comes with very concise and clear instructions, and installation should be a pretty straight forward job for anyone who knows how to use a wrench. As with any dropper post whose actuation takes place at its head, it is best to at least ballpark your saddle height before trimming the housing in order to be sure that you nail the correct length the first time, something that requires bolting your seat in place if you don't know your measured height to the seat rail clamp. The opposing horizontal twin 4mm hex head rail clamp bolts make this much easier than the more common inline vertical bolts because you aren't required to align any inserts or barrels that would otherwise be present. We would like to see a deeper tool interface used on these, though, even if the torque required doesn't call for it - something tells us that many home mechanics would appreciate this. With the correct height sorted out we could now remove the seat to give better access to the cable clamping bolt, as well as move on to trimming and installing the cable and housing to the exact length.

pivot doesn't play nice with brakes that use a large master cylinder like that found on Shimano stoppers. The result is that the remote is forced into a position closer to parallel with the ground than we would ever use otherwise. We do admittedly run our brake levers slightly higher than many prefer, but we also ran into the same issue when using the Pulse with Avid's sleeker master cylinder, although to a much lesser degree. To 9Point8's credit, they will mail you a cardboard template of the remote so you can check to see if it works well with your handlebar setup, a smart and thoughtful move on their part, and they are also currently designing a more traditional remote that will be available as a stock option with the Pulse at the time of purchase. .



Performance

Pulse's "third brake lever" remote admittedly had us questioning 9Point8's reasoning for not going with a more traditional thumb operated design after we ran through the post's initial setup, but how does it perform on the trail? Well, we've still got for the same question for them, but the design does pan out better than we first expected. As with anything else control related, the key is having it sit in a position that makes sense for your hands, something that took a few tries for us to get right... or at least close to right. Part of this is down to the aforementioned angle that it sits at due to where our brake levers rest, but reach also plays a role here as the remote's lever blade is a touch short for our liking. This meant we had to stretch a bit to grab it, and it ended up not feeling terribly ergonomic. We did get mostly used to it eventually, and the concept could be made even better with a slightly different shape and perch layout, but we can't help but wonder why 9Point8 didn't employ some sort of smaller thumb remote up against the grip from the get-go as Specialized and KS have done, the two most intuitive setups out there right now. To their credit, they have realized that the current remote won't be for everyone and have designed a push-style version that can be situated either above or below the handlebar, as well as set in either a vertical or horizontal plane. We weren't able to source the new style remote before writing this review, but it looks to be a big improvement, and riders can order it as an add-on when they purchase their Pulse seat post directly from 9Point8.


From the Pulse's remote to its stepping function, the post's action is unlike anything else currently on the market. This became apparent the first time we went to use the Pulse, as the remote sports very distinct action through its throw thanks to the post's two-stage hydraulic valve. Pull the lever part way while weighting the seat to activate the stepping feature and it drops down just 5mm, with it then stopping until you release and pull the trigger again to lower it a further 5mm. This can be done repeatedly to locate the Pulse anywhere in its 100mm of travel in 5mm increments, which means there are twenty different seat heights to choose from. You can also pull the lever past its well defined indexing point to allow it to lower unrestricted. Using the stepping function might sound clumsy when read here but it did work as advertised on the trail, and it could be done somewhat efficiently once we were used to the action. Is it as fast as lowering a non-indexed post such as a Kronolog or Reverb to the desired height? Definitely not, but it does have an assuring feel to it that will prevent you from lowering your seat past the height you were looking for. After much trail-time we would like to see a version of the Pulse that offers 10mm steps instead of 5mm, thereby speeding up the process of lowering the seat - 5mm just seems a bit to exacting for our tastes, especially in the heat of the moment on the trail when approaching a technical move. We also quickly realized that it would be tricky to use both the brake lever and the Pulse's remote at the same time, an act that we wished was easier due to how often one grabs a handful of brake while also trying to lower their seat to prepare themselves as they roll into a tricky section. This was less of an issue on slow speed terrain such as steep roll-ins that one approaches with caution, but much more of a concern when speeds picked up and reaction times become critical. Again, this isn't an issue with thumb operated remotes, and 9Point8's newly designed lever should address this complaint.


The post itself proved to be very smooth throughout its travel, with no jamming or grinding to report during the months and months of abuse we've put it through, an evaluation that saw it used in some pretty terrible weather and countless post-ride jet washings. The travel was also consistently easy to attain, with no noticeable ramp-up in weighting required to compress it near the end of its stroke, something that hampers a few other air-sprung dropper posts on the market. The same can be said of the post's rebound stroke, with it returning to full height quickly but in a controlled way, and its small yet audible top-out clunk is a nice feature as it let us know that the seat was back up to full height. You are also able to use the stepping function to raise the post 5mm at a time, although we didn't find this useful in the slightest when put into practice on the trail - when we wanted to raise the seat, we wanted it raised to full mast. And although the 9.8 utilizes hydraulic internals, the seat can't be pulled up through its travel when lifting the bike in that manner when the seat is lowered, a nice attribute of the Pulse's design. It is also worth noting that it required zero cable tension adjustment after the initial break-in period, meaning that it's far less finicky than some other cable operated designs out there.

Stepping function and remote design aside, potential owners will have to ask themselves if 100mm of travel will be enough for their needs. A few years ago we would have said that yes, that amount of drop is more than enough to get the job done, but now that we've had plenty of time on 125mm and 150mm travel seat posts, we found the Pulse's shorter stroke a bit of a irritant in technical terrain, and especially when faced with any serious jump or drop. This might not be an issue if you've never used a longer travel dropper post, and especially not if you don't often get too rowdy on the trail, but if we're going to install a 686 gram dropper post to our bike, which is heavier than options from KS, RockShox, FOX, and Specialized, by the way, we would like it to have more than 100mm of travel.



Issues

We did discover one major issue with the Pulse seat post during testing: it would creep up in its travel when ridden over extended and extremely rough ground. It was never a lot, maybe only an inch at most, but it isn't a pleasant feeling to discover that your seat is slightly higher than expected mid-way through a gnarly section of trail. This was exacerbated by the post sporting 100mm of overall travel, 25 - 50mm less than some of the competition, which means that every little bit of available drop helps. We originally suspected our test bike's suspension linkage was interfering with the actuation cable, but that was proven to not be the case when the same issue occurred on multiple other test rigs, as well as with the cable completely undone to eliminate the possibility of too much tension being the source of the problem. The issue only occurred on terrain that rattled the bike around quite a bit, which lead us to believe that the post's two-step hydraulic actuation assembly was being knocked into action in such situations and, as it turned out, that was the case. ''No other customers have reported this issue, but after you mentioned it to us, we tested all posts in our warehouse,'' 9Point8's Steven Park told us. ''We discovered that a handful of them would creep slightly under vibration. This was caused by the seal in the main piston. We’ve since begun using a much better seal that does not creep. All posts sold after July 9, 2013, have the new seal, and should any customers discover this problem, we’ll replace the seal for them at no cost under our lifetime warranty.''

Some riders might take contention with the actuation point being on the seat post's head, but we're still adamant that giving the cable proper routing will eliminate any complications on that front - we used a few zip-ties where required and never once had the cable rub either the rear tire or our legs. It won't ever been as clean as the stationary routing found on a KS LEV or Crank Brothers' Kronolog, though, or as resistant to contamination as a design the uses internal routing.


Pinkbike's take:

www.9point8.ca

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