FSA FLOWTRON 150MM DROPPER POST

The right dropper post can make or ruin a bike. It seems like a bold statement, but as a dropper post is now the norm on just about any mountain bike, the good ones really stand out from the bad. A post that gets stuck, sags, moves around a lot or has a lever that’s hard to use might even take more from your trail experience than it gives.

Thankfully, dropper posts have been getting better and better and the short service lives are just about a thing of the past. Best of all, a great dropper post doesn’t even have to come with the higest price tag! There are a number of models available that have excellent reliability and action for a fraction of the cost of some that are out there.

FSA entered the dropper post game with their Flowtron dropper. A 125mm model was soon followed by the 150mm we have had on test and both models come in 30.9 and 31.6mm seatpost diametres. The Flowtron sells for about $400 which puts it about middle of the range on price.

Like the PRO Koryak dropper post we tested in 2017, the FSA Flowtron operates on a sealed cartridge. This has pros and cons for service, as it’s all one sealed unit but typically if there is a major problem the whole cartridge needs replacing – the cartridge is about $120. The 150mm drop unit is pretty long at 470mm, something worth noting if your frame doesn’t have the clearance needed in the seat tube.

SETUP

There is nothing out of the ordinary here, as you measure the outer required and fit it like any other dropper post. The under-bar lever is huge for the Flowtron, and like a Fox Transfer lever it clamps the cable at the bar. The head attaches to the post and wraps around a cam that makes for a very smooth, low-resistance action. The long lever adds to this. While the cable clamp is a little basic and squashes the cable flat (which might lead to frayed cables down the line) it is secure and the lever feel is excellent, although it’s a deep push to lift the post unless you really tighten the cable with the barrel adjuster – once done it is really responsive. I ran the lever further inboard than the Fox Transfer post it replaced, thanks to the extra length and sensitivity.

ON THE TRAIL

Given the prevalence of dropper posts, the best ones are the ones you don’t notice. And straight away after my first driveway setup that is exactly where the FSA Flowtron fits. I had heard their first design got a fair bit of movement and slop, but the new three brass keys that the upper assembly moves on looks to have solved that, with only the same amount of movement in the post after a few months that my Fox Transfer has.

What I did notice though was the lever sensitivity and ease of use. That big thumb paddle is easy to hit, and you can even dial in the spring tension on it to customise the feel. I kept it super light as I found it way easier to then use what most dropper posts offer, which is infinite adjustment. A dropper post isn’t just about slamming it and hanging off the back. You might lower it a tiny amount for a flat corner, or on a technical climb, or lower it a lot on a fast descent to the trail head to get in a speed tuck. A good dropper post will be made or broken by the lever, as that’s how you actuate it. And in this case I really liked the FSA lever, even if I first thought it was too big.

With a super-smooth action, easy cable fitting and such a good lever feel I think the FSA Flowtron is a good option for plenty of trail bikes out there. It’s a little heavier than some, but well-priced and and once setup how you like it you’re likely to get a lot out of the post.