This sport ain't cheap. Sure, we're getting more and more bike for our bucks as each year goes by, but the dream machines at the top of the want-list are usually carbon and usually pricey. Want a Trek Remedy or Yeti SB100 frame? That'll be $3,299 USD and $3,800, please, or you can get an S-Works Stumpjumper 29 frame for $3,200. Yeah, Giant's Reign Advanced rings up at only $2,625 with a DVO shock, but you get the picture: If you want a carbon frame, the price tag is probably going to start with a '3' more often than not. And those examples - or nearly any example you can think of - are all born in Asia. Not that there's anything wrong with that.
Oh, you want a US-made carbon frame? No problem; just send Alchemy $3,999 USD for your Arktos patriot-mobile and brace for a barrage of dentist jokes from your buddies. Shoutout to Ibis for making their size-small front triangle in the US (and selling it for the same price as their Asian-made frames), but it's slim pickings otherwise.
All of which makes the $2,440 USD price tag (w/ a RockShox Deluxe RT shock) for Guerrilla Gravity's US-made carbon frame look pretty damn impressive. So, how the hell can a relatively tiny company out of Colorado, a company that had, up until recently, little to no experience with carbon fiber, offer a frame that's made in America for a thousand bucks less than what we see coming out of Asia?
The answer lies with robots, some out-of-the-box thinking, a lot of hard work, and a bit of luck. Guerrilla Gravity is calling it their Revved Carbon Technology, and it refers to both the materials and methods being used to manufacture their new frames.
There's a decent chance that the carbon frame in your garage is made with Toray T700 or something similar, a relatively common type of carbon that can be bought by bike companies in large amounts. Today's carbon works pretty well, too, aside from it being a bit delicate when it comes to getting hit with pointy things and a bit expensive when it comes to buying a new one. But overall, it's arguably the best option right now if you want to build a lightweight and strong frame.
Guerrilla Gravity, that pint-sized outfit best known for their reasonably priced aluminum frames, says that they have something better, though.
A US-made carbon frame for less than what comes out of Asia? Guerrilla Gravity is doing exactly that with their Revved carbon production.
Thanks to the resin they're using during manufacturing, they claim that their frame is a whopping 300-percent "tougher" when it comes to impact strength. That's a hell of a lot of percents in an industry where an increase of just a few points calls for a bunch of new acronyms. It also begs the question of how a comparatively small company managed to get their paws on this stuff before a larger brand with more resources threw a truckload of money at it.
It turns out there's a plane-building company called Boeing - you may have heard of them - that's been using this stuff for a few years to build large and important portions of their new 787 Dreamliner, but it's only recently become available for others to make things out of.
Guerrilla Gravity freely admits that they happened to be in the right place at the right time to come across these vital ingredients, but it wasn't simply a matter of plug and play; they hired a new composites engineer and spent plenty of time experimenting with different fiber orientation and types.
Originally, they had short-strand fiber that could be purchased in large sheets and then laid down into the mold, but those early prototypes didn't cut the mustard when it came to the frame's rigidity.
The answer took much more work, a lot of trial and error, and a different type of long-strand US-sourced carbon that was mixed with the much stronger resin.
Guerrilla Gravity can now "cook" a frame in just thirty minutes and at a much, much higher temperature thanks to that special resin. For reference, they said that a traditional carbon frame can take three to four hours to cook, and while theirs comes out of the mold needing only minor sanding and love, the normal process could call for a lot of hands-on work to turn it into a finished product.
Molds can cost a lot of money so Guerrilla Gravity made their own, as you do.
Also, because the resin can handle much higher temps, they can go with a more durable powder-coat finish for their carbon frames. That's supposed to be better for the environment, too, and the whole thing is said to be far safer for everyone involved.
The process ended up being so forward-thinking that Guerrilla Gravity won a $250,000 USD grant through the Advanced Industries Grant Program that's run by the Colorado Office of Economic Development and International Trade. Serious stuff, especially when it had only ever been awarded to companies in the aerospace, bioscience, and renewable energy industries up until now.
Did you know that essentially every carbon fiber mountain bike frame is made by hand? If you walked into a carbon frame-making facility, you'd see a bunch of people laying down hundreds of different and precisely cut small sheets of carbon in a very specific way before sending the puzzle off to be baked in the mold.
It's a time-consuming process, and because human hands are involved, human error can be as well.
You know what doesn't make silly human errors? Robots, of course. ''Using automated fiber placement for the majority of the layup process, we’re able to reduce labor time by approximately 80% while also ensuring quality consistency from one frame to the next,'' says Guerrilla Gravity. That's pretty much all they'd say about the secretive process, but a quick search of the Google brings up plenty of giant robot arms covered in spools of carbon fiber, so it's probably safe to assume that it's along those lines but smaller.
The machine is also bespoke to Guerrilla Gravity, I'm told, which no doubt cost them a pretty penny to set up.
Automated fiber placement has been around for a handful of years now, mostly in the aerospace sector, but Guerrilla Gravity says that using that method to construct hollow, 3D tubes wasn't something that had been done before. That's the secret, patent-pending part, and it required them to investigate new bladder and mold techniques to make it a viable process.
Once the mold is bolted shut it's slid into the Frame Maker 3000 that, you guessed it, Guerrilla Gravity built themselves. Handy folks.
Once the robot has done its thing and the mold is closed, it's off to get cooked in by their 'Frame Maker 3000' machine, a job that takes just thirty minutes rather than hours and hours. The frame that emerges on the other end is then touched up by hand as required before being sent off to be powder-coated. What comes out is said to weigh 6.5lb without a shock, so while it's not the lightest frame around, it's also not the heaviest either.
1 Frame, 4 Models
Being a relatively small outfit has its advantages - being able to switch your entire range from one frame material to another, for example - but as any small business owner will tell you, it helps if you can outsmart your better-funded competition.
Let's pretend that you're a bike company who sources your frames from overseas. The traditional route would be to take an educated guess as to how many frames you're going to sell in all three or four sizes and then place one or two whopper-sized orders each year. If you think that sounds risky, it's because it most definitely is; it's also why you often see those "year end" or "overstock" sales. In contrast to that, Guerrilla Gravity does something they call "Just In Time" manufacturing that's exactly as it sounds: Because they're manufacturing their own frames in-house, they get to decide how many to make and when to make them.
By swapping out seatstays and, in some cases the shock, they're able to share one front triangle between four different models.
The other thing they're doing is a "Modular Frame Platform" that sees a single front triangle used across four different models (and both 27.5 and 29'' wheels) that sit at 120mm, 145mm, 155mm, and 165mm of rear wheel travel. Each model uses its own seatstay kit, and you'll need a different shock for certain configurations, but it's a clever way to do it that certainly saves Guerrilla Gravity some money.
It wasn't that long ago that Specialized got a lot of grief for using the same front triangle for their 27.5'' and 29'' platforms, so it'll be interesting to see how Guerrilla Gravity's approach is received.
The rear-end is aluminum and still made in-house. Each seatstay kit is designed with a different leverage ratio in mind, thereby tuning the suspension to better suit the available travel.
The seatstay tuning kits, which include all the hardware and require only a 5mm and 6mm hex key to install, go for $445 USD, and the idea is that a customer could pick up what he or she needs to effectively have a second bike built for a different purpose. That price doesn't include a different shock, of course, but they'll sell you one of those, too. The idea makes sense on paper, for sure, but I've still never met anyone who swapped between wheel sizes a few years back when that was a "selling feature." Also, you'll need a longer-travel fork for drastic changes, so it's not like the investment will be small. Maybe I'm out to lunch, though, so let me know what you think in the comment section.
The frame comes with a nifty adjustable headset as well, with an insert up top that can be rotated to give you 10mm of reach adjustment and a lower cup that be had with 0mm or 15mm of rise to compensate for a different wheel size.
An insert at the top of the headtube lets you tinker with reach by 10mm, while 0mm and 15mm high lower cups tune head angle and handlebar height.
Guerrilla Gravity also deserves some kudos for encouraging people to tinker with their setup, even going so far as to describe certain combos that they've found to work well. There's the MegaSmash that rocks a 170mm, 29” front end combined with a 165mm-travel, 27.5’’ rear end. Or the Madd Dogg that gets 120mm front and back, 27.5’’ wheels, and a 0mm lower cup that probably adds up to one hoot of a bike.
You get the picture, and if you end up with one of their bikes and are curious if a certain combination will work or not, there's even a forum, or you can just call them up.
The 120mm/130mm Trail Pistol setup was my preference, and the 'Plush' and 'Crush' modes offer two very distinct rear-suspension options.
The frame can be had in four different "standard" configurations, each listed below, and you can get them in three different trim options. Ride 2 starts at $3,695 to $3,795 USD, Ride 1 will cost you $4,595 USD, and the top-end Race model sells for $5,695 to $5,995. Guerrilla Gravity will let you upgrade or downgrade parts as you see fit, too, so you can spring for the baller suspension and carbon wheels, but save some money by going with an entry-level drivetrain. Again, not only are you not locked into a certain model, you're not even locked into a certain spec.
A small chip at the rearward shock mount (left) lets you change between 'Plush' and 'Crush' modes without altering the geometry. The latter is quite a bit firmer feeling, while the former offers a more forgiving ride. That bolt-on loop (right) is for your Velcro strap to go through, or you can mount a small water bottle below the shock.
• Travel: 145mm
• Fork travel: 160mm
• Wheel size: 29''
• Tire clearance: 2.5''
• 64.6° HTA
• 76.8° STA
• Travel: 155 - 165mm
• Fork travel: 160mm
• Wheel size: 27.5''
• Tire clearance: 2.6''
• 64.5° - 65° HTA
• 77.2° STA
• Travel: 120mm
• Fork travel: 130mm
• Wheel size: 29''
• Tire clearance: 2.6''
• 65.9° HTA
• 78.2° STA
• Travel: 130 - 140mm
• Fork travel: 150mm
• Wheel size: 27.5''
• Tire clearance: 2.8''
• 65.8° HTA
• 78.2° STA
What does all the mean? The material and methods that Guerrilla Gravity is using allow them to build their carbon fiber frames in much less time and with much less labor required, which means a less expensive finished product. It's said to yield a considerably stronger frame, too, and one that's takes less of a toll on the environment to produce.
Less expensive, stronger, and made in the US to boot... This Revved thing sounds too good to be true, doesn't it? It certainly does, but it also really does look like Guerrilla Gravity is about to take the leap from what is essentially a small but much-loved cult brand to something that could have a much, much larger impact.