FSA Flowtron Dropper Seatpost

FSA Flowtron Dropper Seatpost – $250

By Scott Williams


In late 2016, Full Speed Ahead (FSA) announced that it would discontinue its Gravity dropper post series to avoid confusion with the brand, GravityDropper.The Flowtron takes its place with a completely redesigned the remote, improved durability and a couple hundred less grams. The Flowtron has infinite adjustment and is internally routed in 125 or 150mm travel lengths for 30.9 and 31.6 mm diameter seat tubes.

Inside, the cam-actuated dropper sees an upgrade from the old two-key design to a more robust three-key design to reduce rotational play and improve durability. The post can be serviced by the home mechanic in about 15 minutes with the service kit, which includes the three cylindrical brass keys, glide bushings, and seals. FSA also made a switch from a steel-walled cartridge to an alloy cartridge to help reduce weight. Unfortunately, the Flowtron does not provide any adjustability for air-spring pressure, so if the return speed of the post begins slow, the entire cartridge will need to be replaced. If this occurs outside the two-year warranty period, a replacement cartridge is available through the company for $50 and can be easily swapped by the home mechanic with basic tools and a strap wrench.

Externally, the Flowtron offers a newly designed under-bar remote with a massive ribbed thumb paddle that provides an internally adjustable spring load (more on that later). On top, the two-bolt head of the post saw an improvement in a reduced profile, which provides maximum saddle clearance.


Winter, a bike component’s kryptonite; if there are any design issues, a salt-infused, temperature-fluctuating, wet, muddy, Northeastern winter will certainly expose them in a hurry. I did not experience a single performance issue with the post’s functionality through the winter and spring testing period, even with plenty of miles on wet and salty roads.

Installation is made easy by inserting the cable from beneath the dropper post and feeding it through the frame where it is clamped down at the lever. However, don’t toss the provided instruction sheet into the trash; you’ll want to take a look prior to setup. At the bottom of the dropper post, the Flowtron utilizes a wound spring that can be set in three positions allowing the rider to adjust the firmness felt through the lever throw. Note, this will need to be set prior to feeding the cable to the lever.

If you are particular with your cockpit setup, you could potentially run into some remote/brake lever real estate issues as I did with my Shimano XTR brakes. Ideally, I would have liked to rotate the remote more inwards, but the single-bolt clamp interfered with the brake lever. Joel Richardson, product development and R&D, stated, “We acknowledge the angle limitation of the remote and this brake lever [Shimano]. The remote design uses a common hole for the clamp and pivot in order to reduce weight, cost and improve cosmetics (hide the bolt).” If you do happen to run into this problem, aftermarket levers such as the Wolf Tooth Light Action remote (also a single-bolt clamp) will work just fine.

The 30.9/150 mm post we tested tips the scales at 566 grams plus an additional 46 grams for the remote. Overall, at $250, which includes the remote, this is a well-executed mid-tier priced dropper that could prove to give the current top-tier dropper posts a run for their money.