Tested: Fasst Flexx Enduro Handlebars
Small-bump compliance disguised as a handlebar
Alloy or carbon fiber
Vibration and impact damping
Works exactly as advertised
Many options available
Adjustable to rider weight
Great for riders nursing injuries
Heavy (for bars)
Upsweep changes under load
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A handlebar is a handlebar, right? Not quite—handlebars are as diverse as the bikes they control and the riders they support. There are different materials, different diameters, different shapes and sizes. But from a distance, a handlebar is just a tapered and bent tube … with the obvious exception of the Fasst Flexx bars. They’re so far down the not-handlebar path that one could mistake them for suspension, not handlebars. The thing is, one wouldn’t really be mistaken.
Fasst Flexx bars are elastomer sprung/damped suspension handlebars. They were originally developed for bikes that go BRRR! to address hand fatigue due to motor vibration and high-frequency impacts. Eventually, the odd-looking bars made their way over to quieter two-wheeled antics. While not dealing with motor vibration, mountain bikes certainly deal with plenty of sharp and/or high-frequency impacts that, with more traditional bars, translate right into the hands.
You might be thinking, well, aren’t there bars, like the excellent OneUp Carbon bar or Spank Vibrocore, which are designed to reduce those things and make riding more comfortable? Sure, but comparing any traditional bar to the Fasst Flexx is like comparing a fatbike tire to a suspension fork. Yeah, they both are squishy and do the job of absorbing energy, but one does that job a fair bit better than the other.
Fasst Flexx bars are, in a word, superior to traditional handlebars when it comes to pure vibration mitigation. I hesitate to use the words “vibration damping,” because that only describes half of the equation—the Flexx bars are suspension, albeit fairly simplistic suspension. They do have adjustability in both spring rate and damping for both compression and rebound by way of their two elastomers. Yes, elastomer suspension, but those who remember the horrors of old elastomer suspension mustn’t fret—these modern plastics won’t dry rot overnight or melt into goo if left in a hot shed (that one’s a funny story).
No, the Fasst Flexx bars are modern, through and through. You can get them in carbon fiber or alloy and with a variety of geometry and hardware options. The bars tested were of the alloy variety with titanium hardware, a 25mm rise and a generous 12 degrees of back sweep, but there’s a more traditional 8-degree option as well. In stock form, the bars come 800mm wide and provide 5 degrees of vertical travel, though the actual amount of travel depends on bar lengh. Cut-down bars won’t travel as far as full-length, nor will they have the same leverage on the elastomers. For the latter reason, I cut down the test bars to 785mm, the width I run on my personal bikes, to best compare the feel of the Fasst Flexx bars to other bars.
Earlier, I used the analogy of a fatbike tire versus a suspension fork to compare the Fasst Flexx bars to traditional bars—I’ll expand on that. I used to have a Surly Moonlander with 4.8-inch tires (ran at 5psi) and a rigid fork. At the same time, I had a Transition Vanquish with 2.2-inch tires (ran at 25 psi) and a 120mm Fox 34. Both bikes had very nearly the same amount of vertical travel when it came to how far the bars would move if you hit something hard enough, but, of course, the Fox 34 did a much better job in terms of feel and control moving through that travel than the 4.8-inch fat tires did. Switching between the two bikes was a night and day difference, and switching between the Fasst Flexx bars and traditional bars is just as noticeable.
The Fasst Flexx bars are a very unique experience, but one that feels natural and requires no adjustment in riding style. The best way to describe the ride-feel is to describe it as simply controlled—and that’s a two-part breakdown.
At the surface, there’s vibration mitigation. The Fasst Flexx bars aren’t noddles, they are actually extremely stiff fore and aft. And in the classic car-park test, they don’t have much give up or down with the firm elastomers. But on the trail, those tiny, super-high frequency impacts that aren’t fully absorbed through the tire or fork do get absorbed. It’s almost like the grips are suddenly made of memory foam—it’s firm but soft at the same time. Like a good suspension fork is supportive yet supple, the Fasst Flexx bars flatten the vibration spike but still provide the basal feedback from the trail.
There’s a trail I regularly ride that, by the bottom, I have to slowly peel my hands from grips and gently shake my fingers out. It’s steep, and it alternates between all-out, death-grip chunder and heavy-on-the-anchors braking through said chunder. Generally, this is a recipe for hand fatigue and pain. The first run on the Fasst Flexx bars was pretty uneventful until I got to the bottom and realized my hands weren’t hurting. Sure, my forearms were still pumped, but there was a complete lack of Whistler-Finger Syndrome. Claimed vibration mitigation? Check.
And then there’s the vertical travel of the bars. While high-frequency vibrations are one thing, the sting from a hard bottom-out is another entirely. How well the Fasst Flexx bars deal with the bigger impacts largely depends on the stiffness of the elastomer inside. There are four elastomers provided, which are meant to provide tuning for rider weight as well as riding style—just like a suspension fork.
During testing, I settled into running the second-firmest (red) elastomers, although I experimented up and down the stiffness tree. I weigh, depending on gear, around 230lbs and ride fairly aggressively. The red elastomers were a good all-around aggressive trail/enduro fit, providing plenty of vibration damping while still keeping some support for larger hits. If the bars were on my XC hardtail, I might run the next softest damper, which wouldn’t stand up to the big hits but provide a very cushy feel. If the bars went on a DH rig or the day was to be spent in a bike park, I might bump up to the firmest elastomers to take more of the big hits. It’s a balance to find, and an inverse relationship to navigate, just like regular suspension.
As tested, with the red elastomers, the bars act like an extra-thick bottom-out bumper. Yeah, the fork will still go “thwack” and your hands might sting a little, but the sharpest edge to the impact is blunted.
And speaking of regular suspension, these bars aren’t a Band-Aid for poor suspension setup or even plain old poor suspension. In the same way that high-end shocks offers marginal gains over today’s mid-tier offerings, the Fasst Flexx bars aren’t game-changing—they’re another level of vibration mitigation with an added level of controllability. If you’re racing or nursing an injury (we’ll cover the latter in a minute), then the reduction of wear and tear on muscles and joints may be ride-changing, but these bars aren’t the same as even, say, adding 10mm of travel to your fork. It’s more muting the trail, like a good tire casing can, rather than simply erasing feedback altogether.
When it comes to adjusting elastomers, the process is fairly easy—once you figure it out. The first time I went to swap elastomers, I felt like I was swapping derailleur pulley wheels for the first time. There’s an order of operations that makes the process go well, and it’s best to abide by it. That includes abiding by Fasst Flexx’s direction of Loctite on the bolt threads.
When swapping elastomers and dialing in feel, it’s important to note sag. Yes, sag. Depending on the stiffness of the elastomer, the bars will actually sit lower or higher into their 5-degrees of travel. This effect is one of the reasons why I chose stiffer elastomers—I have been dealing with hand issues over the last few years, and flatter bars aren’t as comfortable for me. That’s not to mention greater sag means less useable travel to take impacts. With too-soft elastomers, the bars will actually flatten out quite a bit, just like running too soft a spring rate in your fork.
The other potential downsides of these bars are their weight and price tag. At 550g, the alloy bars aren’t light (430g carbon), but then again, a suspension fork isn’t as light as a rigid fork. And a coil shock isn’t as light as an air shock. Pick your poison: vibration mitigation or weight savings (of a couple of hundred grams). And then there’s price. At $325 these are nearly the price of budget suspension forks, and well over twice the price of most carbon bars. Hard to justify? Maybe…
For myself, I’d happily shell out the cost for a set of these bars for the performance and comfort benefits. I’m also a rider who is on a bike as much as I can be, and who shells out for carbon wheels, top-tier suspension, etc. I’m also a rider dealing with ongoing pseudo-hand injuries (ganglion cysts in both hands) that are exacerbated by, say, high-frequency vibrations and joint fatigue caused by riding. With the Fasst Flexx bars, I feel like I can actually complete top to bottom runs on trails that I can’t get close to running nonstop with other bars. That’s not to mention compounded effects of multiple days of hard riding.
That’s the beauty of the Fasst Flexx bars. They’re more than just handlebars. They don’t just steer a bike or provide a place to bolt on controls—they provide real performance and comfort benefits that, for a rider like myself, can make the difference between riding or having to take a day off. At the end of the day (literally) I’m more apt to keep on riding because of these bars. Components that have this effect are worth more than their price tag suggests.