We’ve ridden a handful of Fusion Fiber wheels, and we always wonder when this unique approach to carbon fiber might make the leap to other components. Well, we can keep on wondering, but the prototype handlebar that Forge+Bond sent to Travis last month has us thinking about the future.
*Editor’s note: This post was written before the Forge+Bond handlebars had been made available for retail sale. These were just a production-ready prototype we had been sent to share our thoughts on. Depending on their stock, Forge+Bond has the bars available to buy for $265. Check out our press release on that news here, and Forge+Bond’s product page here.
I believe that we still have a ways to go before the modern mountain bike reaches its peak. On-bike storage could be more thoughtful, dropper posts could be more reliable, and maybe gearboxes could even go mainstream. But I feel like, on a material level, we hit the ceiling a while ago. Latex-based tubeless tire sealant, hydroformed aluminum, and good ol’ carbon fiber may all still be slowly inching forward, but I can’t imagine any one of them getting totally replaced. I had given up hope of ever witnessing another monumental shift in the stuff our dreams are made of. Until Guerrilla Gravity’s Revved Carbon.
I know that’s an odd way to segue into the obligatory Fusion Fiber origin story, but stay with me. The “carbon” part of Revved Carbon was pretty much the same as normal carbon. It was just held together with thermoplastic resin instead of epoxy resin. “Thermoplastic” was once a dirty word thanks to ill-fated experiments like GT’s lugged carbon frames. But Guerrilla Gravity had something special in their materials and their methods. Although their frames were heavy by carbon standards, they held a lot of promise. Thermoplastic resin can be more impact-resistant than traditional carbon, and can be recycled into simple, solid objects. Unfortunately, Guerrilla Gravity recently became one of the casualties of the industry’s COVID-boom withdrawal. Unless someone picked up the torch when Guerrilla Gravity’s intellectual and physical assets went on auction, Revved carbon’s legacy may have started and ended with a few modular frames.
But sometime between Guerrilla Gravity’s rise and fall, aerospace-industry innovators, CSS Composites, unveiled Fusion Fiber, their own thermoplastic carbon. It was originally developed to make commercial airline construction quicker, simpler, and more efficient. Unlike traditional epoxy-based carbon, thermoplastic carbon sheets are shelf-stable, easier to work with, and their assembly can be partially automated. Plus, just like Revved Carbon, Fusion Fiber can be chopped, melted, and recycled. Revel, Chris King, and even Trek have partnered with CSS as the third-party rim manufacturer for their house-brand carbon wheels. Rims are a complicated first step onto the carbon market, but they make for a logical application of Fusion Fiber thanks to its durability and natural impact-damping characteristics.
My go-to analogy for what sets thermoplastic carbon apart from traditional carbon is hot glue versus super glue. Hot glue is much less brittle and much less rigid. Then last year, CSS launched their own brand, Forge+Bond, where they would showcase the latest innovations in Fusion Fiber. Although their first innovation was just a slightly more advanced line of carbon rims, Forge+Bond became the place to watch if you’re waiting to see what else could be made out of this material. And we finally got a pretty big clue.
By “clue,” I mean that this is not a normal product release. At least not for the bike industry. Think of it more like a teaser trailer for a video game that may not see the light of day for months or years or maybe even ever. When I sat down to write about my experience on the Forge+Bond Handlebar, I had no press kit to paraphrase and no manufacturer web page to link. I don’t have a shred edit, a release date, or even a price (though I’m told they wouldn’t be cheap). I just have a handlebar, a few numbers, and a head full of thoughts.
Forge+Bond Handlebar Quick Hits
- Made in Utah from Fusion Fiber proprietary thermoplastic carbon
- 35 mm clamp diameter
- 800 mm width
- 25 mm rise
- 5° upsweep, 7.5° backsweep
- Not yet available for retail sale
First, just to be clear, these bars are not made out of recycled Fusion Fiber. Forge+Bond is actively working to expand that roster beyond just tire levers, but the hollow, thin-walled shapes of a rim or handlebar need to be made from virgin material. So, these bars use the same stuff as the rims. And they include evidence that Fusion Fiber doesn’t require excessive sanding or finishing. I could faintly see mold release lines dividing my (pre-production) bar’s front and rear hemispheres. If Forge+Bond hadn’t taken the time to add some subtle branding, they probably could have dropped these in the mail still hot off the press.
The outermost layer’s velvety fibrous waves only really shine in direct sunlight. The bars have a dull, almost bead-blasted finish. Again, these are pre-production, but they feel more industrial than the fancy, expensive carbon structures that I’m used to fondling. Despite their high-tech yet understated look, they don’t have that carbon vibe if people still use that word. But they do have the carbon weight.
My 800mm wide, 25 mm rise, 35 mm clamp, all-mountain handlebar weighed 258 grams. That’s a little more than the 240 g for an Enve M7 bar or 220 g for a carbon OneUp. 20 to 30 grams isn’t nothing, but, like, come on. It’s close to nothing. And handlebars aren’t unsprung weight like rims, making those grams even harder to notice. The extra weight does make sense, though. Fusion Fiber rims trend heavier than their traditional carbon competitors. But Forge+Bond didn’t set out to make the lightest merch on the market. They’ve got loftier goals.
Ride impressions
When I first got news of a Fusion Fiber handlebar, the above image is exactly what popped into my mind. Those wavy lines don’t literally represent the waggle of the bars. The Y access represents angular acceleration, and the X axis represents time. Impacts that originate at the wheel and travel up to the stem will always result in vibrations, but the vibrations are less intense on the Forge+Bond handlebar than on the traditional carbon bars they tested against.
And that makes sense. Fusion Fiber’s unique properties ought to offer a significant reduction in vibration. When riding Fusion Fiber rims, I can point to a few scenarios where they feel different than normal carbon rims, but I really have to stretch. Rim feel is buried under so many other variables that it’s very rare that anything stands out. In contrast, a handlebar is just dangling out there naked. There’s no better component to show what Fusion Fiber can do. So, to find out exactly what that might be, I compared this bar to one of my favorites.
This is the alloy OneUp handlebar. Thanks to the flat-oval profile at its bends, this is the most comfortable 35 mm bar I’ve ever ridden. A more fair comparison would be a traditional round bar made of traditional carbon, but these are extraordinary times, so I wanted extraordinary proof. And anyway, I don’t own a traditional carbon 35 mm bar.
I toyed with the idea of having someone help me with a blind test, swapping bars somewhere out of my sight, and sheathing the exposed sections with an inner tube or something. But I think I’d notice the half-degree less backsweep in the Forge+Bond handlebar. Or I think I think I’d notice it, which is enough to throw me off. Instead, I did several rounds of back-to-back laps on a familiar, chunky, 10-minute-long downhill. Sometimes I started with the Forge + Bond bar, sometimes I started with the OneUp. Sometimes I did two laps on each. Once, I even went back and forth four times. And ya know what? I couldn’t tell the slightest difference.
And not for lack of trying. On top of all my clumsy trailhead wrenching and re-wrenching, I was carrying good speed over bad lines and staying in race mode for sections I’d normally just pick my way through. I actually got a fair bit faster on that trail through this experiment. But every time I’d notice a hard hit was softened by the Forge+Bond, I’d notice a similar one softened by the OneUp on the very next lap. Neither bar left me with more or less fatigue or more or less arm pump. And believe it or not, I think that means the experiment wasn’t just a success, it was a success in Forge+Bond’s favor. Again, the OneUp alloy bar is extraordinarily comfortable for a 35mm bar.
This is a good time to mention that I’ve ridden BTCHN titanium bars. And if you read “comfort” to simply mean “compliant,” BTCHN, Doom, and similar 22.2 ti or steel bars will always be at the top of the list. But for the type of mountain biking I like to do, they’d take some getting used to. There’s a springyness to them that I think some people might find unsettling. That’s why I think the Forge+Bond handlebar is in a different category. And yet, it doesn’t quite fit in with the existing carbon landscape either. Even though I don’t find it to be noticeably more comfortable than any other carbon bar on the market, I do find it more trustworthy.
This is why I started with that Guerrilla Gravity comparison. I bought one of their frames a few years ago. It was an overbuilt, coil-sprung, short-travel, mixed-wheel freak show. It was fun for a while, until the novelty eventually wore off. But we had some good times. And at the peak of one of those good times, I destroyed the front triangle … kinda. Going full tilt on a wide, high-speed trail, I kicked up a long, narrow rock with my front wheel. It was long enough that one end jammed into my down tube while the other end was still embedded in the ground. It almost pole-vaulted me over the handlebars, but after a brief nose-wheelie, I rode it out. Crazy to think how much force was concentrated in that tiny space. Once I had collected my wits, I leaned down to inspect the damage.
I could hardly believe it. I expected to have punched a big enough hole in my downtube to slide a burrito into. But nope. Just this. It was pretty minor, considering. And pretty localized. I did the ol’ bottom-bracket flex test, listening and looking for carbon crunching on carbon, but the bike was as stiff as it ever was. Now, this was the first descent on what was going to be a multi-peak 7,000-foot day. The dirt was wet and the air was cool. Seemed a shame to waste it. So, I just went ahead and finished the ride, not holding back in the slightest on the downhills. That experience is why I trust thermoplastic carbon. It gets me more excited about its potential than any graph of wavy lines ever could.
I can’t think of a component where trust is more important than on a handlebar. I shudder to think what a catastrophic handlebar failure would feel like. And with this type of carbon, minor damage is less likely to cascade into catastrophic damage. I know I’m usually the one flying the biggest pro-carbon flag here at The Radavist, so I shouldn’t be the one calling for carbon to be stronger before I trust it. But I’m less paranoid about catastrophic damage when it comes to frames. Frames are usually a series of triangles. There’s a lot of support and redundancy in a frame that just isn’t there in a handlebar. That makes this a pretty exciting step for Forge+Bond, especially if you look at their trajectory.
They started with rims. Although rims are probably the perfect place for carbon that’s more compliant and less likely to grenade on impact, they’re also probably the most complicated component you could ever try to make out of carbon. But given the growing list of wheel brands speccing Fusion Fiber rims, it seems Forge+Bond has figured it out.
And though handlebars seem to be a simple structure, you don’t have dozens of spokes supporting them from all angles. Plus, like I mentioned, you definitely don’t want them to break. So, if durability claims on the Forge+Bond handlebar are true, and if they do eventually come to market, that’s another pretty challenging hurdle to have crossed. It seems like it may only be a matter of time—even if it may be a long time—before we see domestically made, durable, recyclable carbon fiber frames. So, if these bars are from the future, the future is bright.
See (slightly) more at Forge+Bond
