Fasst Flexx Handlebar Review
Released last year, the alloy Fasst Flexx Handlebar uses a pivot point and internal elastomer to isolate your upper body from excess vibrations. We’ve been testing one over the last few months to see how it works for bikepacking and trail riding. Find Miles’ review here…
Using elastomers in stems, seatposts, and handlebars to soak up vibrations is nothing new, but the technology and product development continue to improve, which has helped introduce a new wave of hand, arms, and body-saving components. Most of these parts rely on swappable, high-density rubber elastomer-dampened pivot points to help soak up the vibrations of the terrain beneath their riders. In theory (and practice for lots of people), it makes a lot of sense, but the tradeoff is the added weight—and price—that comes with the extra moving parts.
I was curious when Fasst released their aluminum Flexx Handlebar last year for several reasons. First, because my hands take the majority of the mistreatment while riding, and also because I kept seeing them pop up on ultra-endurance racers’ bike setups. The fact that it was $100 cheaper than their premium carbon version certainly didn’t hurt, either. The Flexx Alloy bars are offered in both Enduro (800mm width) and DH (810mm width), with 8° and 12° of backsweep, and weigh in at 550 grams (100 grams heavier than their carbon counterpart). The bars are made from 7075 Aluminum and include four elastomers that control the compression and rebound of the bar: soft (blue), medium (yellow), hard (red), and extra hard (black).
While I’ve tested the Flexx handlebars on several bikes over the last few months, they spent the most of that time on the recently reviewed Chromag Surface Voyager. Coincidentally, this bike has also seen the majority of the multi-day bikepacking trips and rowdy trail rides I’ve been on since last year. The stock aluminum bars that came on it weren’t the most comfortable flat bars I’ve used, so I was curious to see what effect Fasst Flexx would have on my experience riding the bike.
Thoughts While Flexx’n
The Fasst Flexx bars come with the hard (red) elastomers installed, which they recommend as a good baseline for most riders. I spent most of my time using these elastomers as they weren’t noticeable while riding, although they were clearly having some effect on the bumps and chatter from the trail. Fasst explains, “Smaller riders, or those riding mellow trails (or gravel grinding) usually prefer the blue or yellow compression elastomer. The red elastomers are harder and provide a more traditional feel. The black elastomers are extra hard, mostly reserved for larger, more aggressive down hill riders. It’s mostly personal preference, and with a little testing you can quickly tailor the bar to your needs.”
The idea behind the bars is that they should absorb excess vibrations from the trail, without affecting handling, and therefore reduce fatigue in your upper body and hands. Without getting too bogged down in the details, I’ll say that the shock-absorbing design of the Flexx handlebars definitely accomplished this. On a mountain bike with front suspension, the handlebar movement was nearly impossible to identify while riding, and it had no effect on handling. The flex was more noticeable on a rigid setup, but I still never felt it hindered any aspect of the ride. At almost 200 pounds and with a semi-aggressive riding style, I think the red elastomers were the right choice for me. In fact, I found it difficult to even demonstrate how the bars flex to friends while stationary. For me, the red elastomers had a firm feel that was better at absorbing big, sudden impacts over smaller vibrations, making it a great option for technical singletrack where proper handling is paramount.
During a couple of multi-day bikepacking trips, the shock-absorbing qualities of the bars were noticeable enough that I didn’t have to move my hands around as much on the grips to relieve certain pressure points. For me, it’s common to have to give my hands a shake or squeeze after challenging descents or climbs, but I found myself participating in these rituals far less with the Flexx bars installed.
Originally I was worried that the bar’s pivot points would have some effect on strapping a handlebar bag to them, and while it’s not exactly perfect, it can work. The area closest to the stem is chunky and non-cylindrical, which sometimes forced bag straps to slide down towards the centre. Rubber Voile straps held in place better, but nylon straps had a tendency to slip around. Wider set straps, positioned just on the outside of the pivot points, seems like the ideal setup, but not all bar bags have adjustable straps. My BXB Piccolo handlebar bag worked best with the bar, because of its chunky Voile strap attachment and stabilizer dowel. I also used the Revelate Designs Pronghorn harness a fair bit, which worked, but the strap spacing wasn’t totally ideal.
To change out the elastomer, it’s a matter of using two 4mm hex keys and removing the nut and bolt, pivoting the handlebar open, and swapping out the compression and rebound elastomers. Fasst also says adding fresh blue loc-tite to the bolt threads is necessary to ensure everything remains tight and secure. The process takes just a few minutes and can be done with the bar and controls installed.
There are refresh kits available from Fasst in the case that the bushings or elastomers wear out prematurely. The kit requires a punch to remove the bushing, which they sell, and an arbor press is useful for setting the new bushing and pin. While I didn’t need to service my handlebar, the process looks fairly simple, provided you have the right tools.
- 30 Day “Ride it, Believe it” Money Back Guarantee
- They actually work
- Made in USA
- No negative effects on handling with correct elastomers selected
- Very expensive for a handlebar
- Heavy at 550 grams
- Standard enduro-style sweep, rise, and width
- Potential for catastrophic failure if not assembled correctly
- Material: 7075 Aluminum and Titanium
- Weight: 550 grams
- Width: 800mm
- Rise/Backsweep: 25mm/8° or 12°
- Place of Manufacture: USA
- Price: $325 USD
- Manufacturer’s Details: FasstMTB.com
Overall, I’m pleased with how the Fasst Flexx Handlebar performed. The simple elastomer-controlled pivot functions as claimed, and while it might not offer the life-changing comfort some of us are after, I can see it working as an everyday solution for unwanted vibrations and bumps, or for big multi-day rides on rocky and rugged trails. The shape and sweep of the bar are somewhat limited due to its design, and it’s not a lightweight solution by any means, but if everything adds up, it could make a great upgrade to your big-day, all-mountain rig.
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