Catch up on all of our Project 1.2 posts here!
With its simple two-bolt head and unidirectional carbon fiber finish, FSA’s entry-level SL-K carbon seatpost is an attractive piece of kit that coordinates well with many of FSA’s cranks, bars, and stems. The company bonds an aluminum head to the full carbon shaft for both cost-effectiveness and peace of mind. Is this $110 seatpost a good way to get more fiber in your riding diet? Hit the jump to find out!
Strong enough for mountain bike use, the FSA’s SL-K posts remain light enough to be seen regularly on road tri bikes. Available aftermarket with either red or white accents (shown), the seatpost is available in 27.2x350mm, 30.9x400mm, and 31.6x350mm sizes. Both 20mm and zero offset heads are available to accommodate different riders and fits.
While FSA advertise a 220g weight for a 27.2x350mm post (Thomson’s benchmark Elite post is about 10% heavier but 20mm shorter), our 31.6x350mm sample actually came in lighter at 211g. Sure, there are lighter aluminum and carbon posts out there, but FSA’s wide OEM spec mean that their posts need to be able to handle the wide range of uses (and abuses) seen by widely-spec’d hardware.
The SL-K’s only demerit an easily-addressed one. In an effort to shave weight, FSA have carved a hole in the saddle cradle- providing
direct access to Narnia a route for all manner of crap to get into the frame. A piece of electrical tape easily sealed off the passage- but not until after our Project 1.2 Lurcher sounded like trailgoing maraca. As anyone who’s tried to tease fine gravel out of a frame will attest, the task is a painful one. The SL-K’s only real fault is easily fixed- but should really be addressed on future versions by FSA. FSA have announced a fix: read about it here! Though it doesn’t provide the same compliance as a flex-tuned seatpost (like Syntace’s HiFlex or Ritchey’s FlexLogic models), the SL-K will damp more trail vibration than aluminum models and appeal to anyone looking for a solid, attractive perch at a reasonable weight. Just be sure to seal up that hole before your first ride.
Note: Post’s shaft does not use FSA’s CSI aluminum core as initially stated. Thanks to our commenters for the correction and our apologies for any confusion!