Forge + Bond Shift AM All-Mountain Review

CSS out of Gunnison, Utah, has been building rims from their proprietary recyclable FUSIONFIBER for quite some time. The rims have acquired a reputation for performance and durability. They've been sold under brand names like Chris King, Revel, Evil, and a few others. Forge and Bond is an in-house wheel company created to sell wheels at direct-to-consumer savings. Forge + Bond sells a wide selection of rims and wheels with different hubs at varying price points, all backed by their 60-day, Love them or Return them policy.

Performance Comparison

Product Specifications

Forge + Bond is making a rim that is fundamentally different from most of the carbon rims on the market today. The carbon fibers they use are largely the same as used in other thermoset carbon fiber layups, but they use a different matrix. A thermoset rim typically uses some type of epoxy, whereas Forge + Bond uses nylon to create a thermoplastic.

A typical thermoset carbon rim is laid up and cured in a one-step process, with the epoxy creating an unreversible bond through a chemical reaction. A Forge + Bond rim doesn't rely on a chemical reaction to cure the rim in the proper shape. Instead, the thermoplastic material is heated to a high temperature and essentially conforms to the shape of the mold. This allows them to form and re-form it again, but more importantly, it keeps them from becoming brittle. This process also has the advantage of being recyclable.

Each thermoplastic rim begins as three large pieces: two sidewalls and a center rim bed. These large pieces are essentially stamped under high pressure, where they get the “Forge” part of their name. Those pieces are placed together under very high heat and pressure to assemble the rim. No epoxies or resins are used in this process, and the “Bond” comes from pressure and heat. The rims end up with a unique shape and finish as more material is used near the spoke holes, giving the rim center a scalloped look.

The All-Mountain wheelset I tested uses F+B Shift hubs made by Bitex; they're respectable, fairly lightweight, sealed cartridge-bearing hubs with 6-bolt rotor mounts and standard Boost spacing. The freehub uses two sets of three pawls to provide 162 points of engagement and is available in XD and Micro Spline flavors.

The rims have no offset, and they use conventional 3x lacing. Both rims have a depth of 22mm, but at 530 grams, the rear rim weighs 50 grams more than the front for enhanced durability. 28 Sapim CX-Ray J-bend spokes connect them to the rims that have 30mm internals and measure 38mm on the outside. The rims use a hookless bead and arrive with tubeless tape and valve stems installed.

Ride Quality

Forge + Bond claims that FUSIONFIBER has “Superior vibration damping and compliance over traditional carbon wheels,” and we'd have to agree. I've ridden several sets of these wheels with different hubs and brand labels over the past few years and have always been impressed with their feel. I don't exactly notice the vibration dampening in the rim, but I do pick up on a unique poppiness to the wheels that provide a smoother and quieter ride feel. As of this writing, I've spent about 4 months on the AM wheels and have nothing but positive things to say about them. The claimed weight of this wheelset is 1832 grams, so they're not exceptionally lightweight, but they ride with an airy lack of resistance.

I tested these wheels while I was testing the RaceFace ERA and Enve M6 wheelsets, so comparisons are hard to resist. The Forge + Bond wheels are heavier than both, and there was no hiding it, which isn't necessarily a point against them. Like the Zipp 3Zero Moto wheels, they have a dampened quality that makes the wheel feel calm and stuck to the ground, and the traction is outstanding. What stands out to me about their performance is how they liven up the bike; they have some flexibility that allows you to load them up on a launch or deep in a corner. They feel springy, not spongy; negative attributes were hard to identify. While that flexibility gives them a lively feel, they're not reluctant to accelerate or change directions. They're positively snappy and pop off lines and lips with a kinetic bounce that feels uniquely thermoplastic.

Freehub Engagement

I'm a fan of fast engagement, and the 162 points of engagement in the hub body are met with two sets of three pawls on the freehub body to provide 2.25 degrees of movement in the ratchet. This makes the wheels feel spry and reactive and, to some degree, masks their weight compared to the 1608-gram Enve's with 4.5 degrees of engagement. I liked how they sprung to action when I mashed the pedals; they always felt ready and never lagging or clunky.

There are a few wheelsets that we've tested with faster engagement, but let's not lose sight of the price point. Sure, the Industry Nine Solix wheels snap to attention at .59 degrees, but they cost more than double the price. There is also a camp of riders that believe some hubs engage too fast and transmit backlash from the suspension into the drivetrain. I don't personally experience the downside of fast engagement, and to some degree, it seems like an excuse for not making or using a better product.

Weight

I generally feel the less rotation weight you have in your wheels, the better the ride. This is a broad generalization and doesn't consider durability, compliance, and deflection. The Zipp 3Zero Moto wheels, for instance, are insanely fast because of their remarkable compliance, yet they tip the scales just over 2000 grams. Older Enve M-Series wheels were incredibly lightweight but had so little compliance that they made you feel fatigued.

Forge + Bond for advertising a weight of 1832 grams, our test wheels weighed a respectable 1,849 grams with tape and valves. Nothing about the weight of the wheels jumped out at me; they don't spin up as fast as wheels with lighter rims but they're by no means lethargic feeling. Notably, these wheels do not have a weight limit, and according to their customer service, “There's nothing about these wheels that would prevent you from using them on an E-bike.” After hearing this, I slapped them on a new Levo SL weighing around 40 pounds and gave them a half dozen rides. They drastically improved that bike's comfort, control, and responsiveness and had zero negative attributes that I could identify.

Durability

Just how durable are the Shift AM wheels? In the 4 months I spent riding them, I didn't find the limit of their durability. I encountered drops galore and a couple of cased landings that resulted in rim outs loud enough to make me stop and inspect. I repeated runs down a trail that resembles a dry creek bed (ok, maybe it is), and the wheels are no worse for wear. No burps of sealant, loose hubs, sticky freehubs, and only minor truing of the wheels was required.

When the AM wheelset landed in my office, one of the first things I did was inspect them and record the tension on each spoke. By recording the spoke tension when the wheels are new, I can compare those values to measured values at the end of the test period. When snow covered the ground and I pulled the tires off, I found the spoke tension within 10% of starting values across all spokes. The relative spoke tension was near perfect, and the wheels were round, dished, and only a touch out of true. Despite the abuse I put into these wheels, it doesn't always feel responsible to make assertions about durability after a half-season of riding, but that's the world of bike reviews. I rode with every intention of trying out their warranty service, but the wheels held up quite well. While I can be clear about the limitations of our testing, Forge + Bond backs these wheels with a lifetime warranty.

Forge + Bond also has a crash replacement program for things that might happen to your wheels when you're not riding your bike. Get rear-ended with your bike on the back of the car? The crash replacement program will get you back up and running for a “nominal fee.” I've spent considerable time on Revel and Chris King wheels that use the same rims and never had an issue with the durability of the wheels. If they hold up as well as we think they will, their value proposition is even more attractive.

Value

Premium quality carbon (err.. Thermosplastic) wheels aren't cheap but represent one of the most significant performance increases you can make on most trail bikes. Most bikes under $7000 are spec'd with wheels in the $500 range that are generally heavy and have poor freehub engagement. I spoke (see what I did there?) about the warranty above, but a lifetime warranty should be considered a substantial value. Revel sold these rims with I9 hubs for $2200, and Chris King sells these rims with their hubs for $2300.

Conclusion