FSA Flowtron Dropper Post AndrewM
REVIEW

FSA FLOWTRON Dropper Post Reviewed

Words Andrew Major
Photos Andrew Major
Date Feb 8, 2019

FLOWTRON V.2

Full Speed Ahead's 150mm FLOWTRON dropper post is a great addition to the increasingly crowded 250 USD uppy-downy post price zone. Of particular note is the forward-thinking clamp layout that helps deliver that modern over-the-bottom-bracket pedaling position even on bikes that are over-forked or have slacker-than-cool seat tube angles. 

I love the direction posts are moving. There are some standout high-end posts like ReVive but I have loved watching the general travel and reliability go up while prices come down. The more competition the better and the FLOWTRON is a worthy contender. 

FSA Flowtron Dropper Post AndrewM

Do you want to sell aftermarket dropper posts? Help riders steepen their effective seat tube angles - it's easy. 

FSA Flowtron Dropper Post AndrewM

Clean one-piece post head and a fully forward saddle on my over-forked (170mm) Honzo thanks to swappable clamp orientation. 

In addition to the now familiar Wintek cartridge layout, FSA adds multiple leverage options to vary the feeling of the remote (highest leverage for the win), the forward saddle clamp orientation, and a really clean one-piece shaft/head. 

The FLOWTRON suffers with the same issue as Bontrager's equally priced Line. It's a great seat post, and a solid value, with the same name as a crappy product that proceeded it. It's hard to blame either brand. FLOWTRON is a pretty good name that has me thinking 1986 Transformers movie every time I say it and 'Line' items are ubiquitous for Bontrager. I never used the earlier iteration of FSA's dropper post, but it's pretty easy to say that this is the product they should have put out originally. 

Action

When I push the FLOWTRON down manually, it's not as smooth as Gucci options like the ReVive or the Fox Transfer. That doesn't matter a whit in the woods when I push the button and slam my ass onto synthetic leather and this post is actually best compared to more expensive options out on the trail. In the months I've been riding the post it has undramatically returned my saddle to climbing height with every activation. It goes down when I sit on it, and it's stayed nice and tight. That meets my action expectations. 

FSA Flowtron Dropper Post Kona HONZO AndrewM

Plenty of torrential days cycling the FLOWTRON on my Honzo...

FSA Flowtron Dropper Post Waltworks AndrewM

...and the FSA post has been doing rainy day duty on my Waltworks as well. 

Return speed is acceptable but much slower than the race-rocket return of my e13 TRS+ or any adjustable air-sprung posts I've used. It's a touch faster than the Crankbrothers Highline and a bit slower than the Bontrager Line. If you like it fast you will find the FLOWTRON slow. I know from the Highline review that a slower return speed is a conscious choice because Wintek cartridges last much longer with a lower charge in them. 

The shaft has developed a little bit of play compared to when it was brand new but it's minimal, even compared to much more expensive options. As with the Line, the balance of free-play vs. return-friction is very well balanced. 

Remotes

Of the myriad posts swimming in the FLOWTRON's pond, it could have one of the best stock remotes. I like the big paddle and solid leverage whether using it with FSA's light-action setting or with other posts with stiffer actuation. 

Unfortunately the FLOWTRON doesn't mesh well with my combination of Presidential thumbs and Magura HC brake lever blades. When I have my brake levers in their magic spot the FSA remote sits either too close or too far away from my thumb for peak initiation.  The easy solution is to adopt a two position clamp like the excellent, and MatchMaker compatible, e13 TRS+ remote or a sliding clamp position like the Wolf Tooth ReMote. In the former example the remote wouldn't look as clean but it could be done without an increase in price. 

FSA Flowtron Dropper Post AndrewM

The FLOWTRON remote is good as long as you can find a happy spot relative to your brake master cylinder. 

E13 TRS+ Dropper Post Remote AndrewM

It would be significantly better, for me, if it had some level of multi-position tuneability like the e13 TRS+ remote I ended up using with the FLOWTRON. 

Formula Cura Brakes AndrewM

I also used the FLOWTRON with my Wolf Tooth ReMote because I could. I have yet to find a dropper post lever action that is too light but this combo was close. 

If the FSA remote interfaces well with your brake levers, for example inside on a Shimano M8000 lever or outside of a TRP Quadiem lever, then I think most riders will be happy with the stock unit. Since the FLOWTRON remote didn't work perfectly with my setup, as with other posts, it would be great if FSA sold the remote separately. If I could pick up this post for 200 USD and choose my own remote that would be ideal.

Do The Teardown

I always learn a lot by taking things apart. Forks, shocks, dropper posts, hubs, disc brakes - all big purchasing decisions. As with most dropper posts with a Wintek cartridge, the FLOWTRON is a pleasantly simple chassis and actuator setup. Spare parts are available in modules; seat clamp assembly, cartridge, tower/actuator assembly, shaft, body and a service kit that includes seals and keyways. If you'd like a look at the inner workings please check out the original teardown article. As always, a big thanks to my friend Jeff of Bikeroom & Wheelthing fame for stepping up with tools, insights, and expertise. 

Even if the cartridge is still working great I'd suggest stripping down the FLOWTRON, and any similar dropper, at least once a year* for a clean and re-lube. Any handy rider with some common tools and time can handle this job at home. It's also something that will be quick and easy for your local shop to pump out. 

*In my experience you know who you are if twice a year is a more appropriate service interval. 

FSA Flowtron Dropper Post AndrewM

Quick teardown at Wheelthing with my friend Jeff. For more information please check out the first look

FSA Flowtron Dropper Post AndrewM

Three brass keyways keep everything nice and tight. Replacements are included when purchasing a seal service kit: Part# 192-0060000010.

FSA Flowtron Dropper Post AndrewM

The multi-position actuator assembly. I prefer the lightest action setting with all the remotes I've used with FLOWTRON.  

FSA Flowtron Dropper Post AndrewM

A replacement Wintek cartridge for 150mm or 125mm drop is available for 50 USD. 

Outside of FSA's 2yr warranty, a new cartridge is 50 USD. It's also possible to lower the post from 150mm to 125mm by purchasing a different cartridge. It's not as simple as installing a spacer but it's still much more economical than buying a new post if a rider finds less drop is desirable. 

Final Thoughts

FLOWTRON. It comes up and stays up. It goes down and stays down. It stops anywhere in the middle. It's going to do that for a tonne of hours of riding and it's easy to service with no proprietary tools or knowledge.

From what I've seen, Wintek owns the dropper post game when it comes to balancing reliability vs. performance vs. simplicity vs. lifetime cost of ownership. While the Crankbrothers Highline is the best example of a Wintek-driven post I've ridden, the FLOWTRON is a great product for 100 USD less. 

FSA Flowtron Dropper Post AndrewM

FLOWTRON is not one of the faster returning posts on the market if that matters to you. 

FSA Flowtron Dropper Post AndrewM

When it comes to pushing the post down there's a good balance of resistance vs. slop.

It would be great if FSA follows up with a 170mm version, since steeper effective seat angles call for more saddle drop when descents get hot and heavy. My experience with this 150mm version leads me to think scaling up would be easy for Full Speed Ahead. 

In the meantime, anyone chasing dropper post value in a 30.9 or 31.6 post with 125mm or 150mm drop would do well to put the FLOWTRON on their list. 

Comments

mrbrett
+1 Andrew Major
mrbrett  - Feb. 8, 2019, 7:14 a.m.

I have some PTSD from my last FSA seatpost experience. The aptly named "Gravity" was almost as bad as a Raceface Turbine v1 - record setting slop, more pull on gravity than an event horizon (it was that heavy), the most sloppy remote I have ever used, and so much play in the saddle I was sure something was broken.

If nothing else, these Wintek posts have standardized some replacement parts and have allowed the seatpost designers to focus on the slidey bits more.

Reply

AndrewMajor
0
Andrew Major  - Feb. 8, 2019, 7:29 a.m.

There have been (previously) plenty of bad Wintek posts too. Totally agree though, now that Wintek has their process dialed the designers of these posts are really just hitting four key points: actuator, seal head, keyways/bushings (slidey bits), and clamps. Plus the remote.

I don’t need the adjustable leverage but aside from that FSA has nailed the actuator (brainless cable change vs say Manic), and all the rest. 

Hear you on PTSD. Had a few comments out and about regarding their old posts (as I did with the Bontrager). The only good news is they’re dialed now.

Reply

Holgerfromgermany
+1 Andrew Major
Holger Baer  - Feb. 8, 2019, 7:51 a.m.

Sorry for being off topic but your honzo screams bike check (like real nerdy bike check). Do I spot an angleset  there?

Reply

AndrewMajor
+1 Holger Baer
Andrew Major  - Feb. 8, 2019, 8:44 a.m.

Thanks! That’s a -2° Works Components angle set. It’s a bit tricky to instal but it’s an awesome piece of kit once in. First look is here and review will come. It’s currently in my Rifty.

Honzo is such a great bike. As a general rule we don’t review our personal rides hence no bike checks. I’m space crunched so my Honzo frame now lives with my friend Terry and the test parts live on my Rifty. Happy to answer any nerdy questions though!

Reply

Holgerfromgermany
0
Holger Baer  - Feb. 8, 2019, 10:40 p.m.

Do you have an Idea how much reach you are „loosing“ by every degree you shave of your hta?

I guess you reduce the stack too?

Reply

AndrewMajor
0
Andrew Major  - Feb. 8, 2019, 10:49 p.m.

You actually gain Reach (and steepen the STA) as you slacken the HTA as the front gets lower.

Then I massively over-forked it and lost Reach that way.

What was the net loss/gain? No idea. It just worked so I didn’t really think about it. Ended up really happy with a 40mm stem.

The bike is/was incredibly capable and fun. My friend Terry who has the frame road it twice and is building it up very similarly to how I had it including fork and headset.

Reply

Kenny
0
Kenny  - Feb. 8, 2019, 7:54 a.m.

Like the reversible clamp, but heard the stack height on these is pretty high - couldn't find a dimension on the FSA site... Any feedback? 

Also, IMO wolftooth remote on Magura clamp with the wolftooth adapter is amazing. Just puts the lever in a perfect spot for my hands. Was going to recommend but then saw you have it! 

I also agree I wish these companies would sell without a lever. I have enough failed dropper lever experiments. I want to buy the coil sprung PNW post, but I have the aforementioned wolftooth on one bike, and a one-up lever on the other. Both work fine. I'm not paying for another lever I won't use. I really think the vast majority of people buying am aftermarket dropper want to pick their own.

Reply

AndrewMajor
0
Andrew Major  - Feb. 8, 2019, 8:38 a.m.

The Magura (also works with Formula Cura) remote setup from Wolftooth is a beautiful thing. I think the Suntour brass barrel adjuster really completes the package.

To my knowledge Fox is the only company currently selling posts sans remote but PNW will also be getting on that program.

FSA is not winning the shortest insertion or extension per travel category if you’re playing for millimeters. 

For most short riders I know it’s the iceberg going into the frame (+ stealth actuator) that’s the issue so a Fox Transfer or PNW post with fixed external routing is the winning choice. If you have an older (tall seat tube) frame and are trying to maximize drop there are better options. 

You’re looking for a seal head to centre of clamps number?

Reply

pedalhound
0
pedalhound  - Feb. 8, 2019, 10:29 a.m.

You can get the OneUp with no remote too. I am thinking about writing up a little review of mine...good post, but far from great.

Reply

Kenny
0
Kenny  - Feb. 8, 2019, 10:43 a.m.

Bikeyoke has a post only option as well. 

I have a transfer 150 and a one up 170. 

The oneup is a pain. Very sensitive to seatpost clamp tightness. You can't torque the clamp to spec, that's for sure. Too tight and the post binds and sticks. Too loose and well, your post doesn't stay put. It also only has 160mm travel. 

The 150mm transfer is so solid, but it's only 150. I might but one of the new 175s but they are on the expensive end of the spectrum now and I could do with lower stack height for one of my bikes.

Reply

twk
0
twk  - Feb. 9, 2019, 6:21 a.m.

I had similar issues with the One Up post in 170mm, but after adjusting the pressure to be a tad higher (close to the maximum it's rated for if I remember correctly) I've had no problems in terms of travel. The sometimes post sticks ~10mm below the maximum extension in cold and muddy conditions, but adjusting it down-a-bit and up-a-bit fixes that, and that could be explained by a lack of service and a winter / autumn of use. A fellow rider seems to be using that post with no issues though.

People's experiences with that post seem to vary, but I'm lucky enough that the post hits a sweet spot in terms of price and quality for me. Also, the remote is nice and cable installation reasonable.

Reply

morgan-heater
0
Morgan Heater  - Feb. 8, 2019, 11:42 a.m.

I was considering one, would you mind listing the not-so-great issues you've had?

Reply

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