Seems it’s the summer of strange forks, first with the new Cannondale Lefty Ocho switching to a standard single-crown design, then the Motion E18 Leaf Spring long travel fork. Now, there’s the Adroit Cycleworks Linkage Fork, and it’s quite the story.
Co-devleoped between Avid Essentials and Adroit Cycleworks, the Linkage Fork’s current iteration has been in development for about two years. There was a version before, but it wasn’t as fully featured as this model. Avid Essentials popped onto our screens earlier this year with their clever retractable bike rack, and brought their expertise in long-travel Jeep suspension designs to the table. Adroit Cycleworks co-founder Aaron brought the bike industry knowledge and carbon fiber construction experience. Together, they came up with a design that promises no stiction, excellent stiffness, and massive tunability.
Why use a rear shock up front?
From a performance standpoint, it’s moving on high quality sealed cartridge bearings at all of the pivot points, and shock pivots run on stock DU inserts (with a bearing upgrade kit available). The benefit is that there’s virtually no stiction, particularly when actually being ridden. But even in the lab, they say without any shock pressure, the weight of a single piece of paper is enough to get it moving. With traditional telescopic forks, not only do you have the friction from the seals, but also drag as fore/aft forces press it against those seals and bushings. None of that applied here.
From a tunability standpoint, they really liked the performance that a Fox FLOAT X2 shock has, and it also has a wide range of high- and low-speed compression and rebound damping. You also have the inhering tuning available through air volume and pressure adjustments. But that’s just the beginning. By altering the shock length and stroke, you can dictate the fork’s travel and height. Move an adjustable linkage and you can tune the progression.
How the Adroit Linkage Fork works:
The design uses upper (green) and lower (yellow) control arms, similar to a most vehicles’ front suspension. the lower shock mount is attached to a shock linkage (blue), which is connected to the upper control arm (green) via a small link (pink).
As the legs move up, the upper arms pull the shock linkage upward to compress the shock. The upper shock mount is fixed onto the included/integrated 32mm stem. The whole thing fits into standard 1-1/8″ to 1.5″ tapered steerer tubes.
The lower steering assembly (red) looks big, but it doesn’t protrude rearward anymore than most big long travel single crown forks. So, if your frame fits a Fox Boost 36 or Rockshox Bluto, they say it should fit this fork. Yes, it looks like it extends farther back than that, but imagine spinning any fork all the way around. If the crown of those forks would clear the downtube, then this should, too.
Adjusting the travel
The fork is designed to be flexible. Not flexy, but rather, adaptable. Stock configuration will have 160mm travel with a 200×57 Fox FLOAT X2 shock. Because it has an almost perfectly linear path, though, all you need to do to adjust the travel is change the size of the shock.
Want 170mm travel? Get it with a 215×70 shock. Want to drop it down to 140mm? No problem, just throw a 165×38 in there. Keep in mind, adjusting the travel will affect the height, so if your bike is designed around a specific fork length, changing it by too much off that intended spec will probably throw your handling and geometry off. You know, same as with any other fork. The mounts are designed around Metric shocks, but you can use non-metric shocks by adding spacers.
Tuning the fork
Two versions of the Linkage fork will be offered, the Base and the Premium. Base version has fixed leverage ratios and dimensions to make it an easy plug-and-play upgrade for most 160mm bikes. It has carbon fiber legs, control arms and linkages, but sticks with an alloy crown and shock link. It’s moving on standard alloy and steel hardware. Claimed weight with shock is 1,895g (4.18lb), and retail is $999. Available for pre-order now, they say they should ship by end of June. After that initial launch, the price will remain the same, but the included shock will likely be downgraded to a DPX2. The upside? The next revision might chop another ~45g off the design. On the Base model, adjustments are limited to changing the shock’s size and using the shock’s built in damping and air adjustments.
The Premium version upgrades to a carbon upper crown, titanium hardware, and an adjustable shock link. This is where it gets more interesting because by moving the upper or lower position of that shock link, you can change the ramp. If it’s slanted more, it gets more progressive. If it’s more straight up and down, it becomes more linear. They say the leverage ratio is 2.6:1 when perfectly linear, but can go down to 2:3.1 by fiddling with it. Claimed weight for the Premium Linkage Fork with an X2 is 1,655g and retail is $1,499.
The fine print
The fork is designed for 29er and 27.5+ Boost wheels and tires. They say you can run a 29×3.0 (aka 29+) as long as travel doesn’t exceed 160mm. Actual travel range is 140mm to 170mm, which corresponds to equivalent travel telescopic forks. It needs to run on bikes with head angles between 67º and 62º. It’s only available with a 51mm offset for now, but they’re working on a 44mm offset for the dual-arm forks to work with bikes like Transition’s Speed Balanced Geometry (and all the other modern trail/enduro bikes with long top tubes and short stems).
But wait, there’s more!
Want to go even lighter? An upcoming Single-sided version uses an L-shaped insert that’s bonded into the lower leg with a standard 15mm thru axle extending from it. Slide your wheel on, then install the special nut on the outside to secure your wheel. That nut is spring loaded, too, so once you reach the recommended torque setting, it’ll prevent over tightening. It’s a clever design that lets you keep using your standard 15mm thru axle hubs, no need for a special “Lefty” version. Current weight of the late stage prototypes is 1525g, mainly because that axle system adds a good bit of weight to be strong enough, but they’re targeting closer to 1,400g or less by the time it’s available in August. Planned retail is $1,199 with the X2.
And that’s not all…
With a perfectly flat compression ratio (it stays at about 2.6:1) and linear rate with the intended shock, it’ll allow for the use of “donor” shocks to an extent. Translation: While it’s designed around a 2017-18 Fox Float X2 with a stock tune, you can put other shocks in there with minimal impact to the rate and ratio. The benefit to this isn’t just versatility, but also cost savings. Search eBay and the forums and you’ll find plenty of lightly used or even new shocks that were taken off new bikes when the user upgraded their own rear shock. So, when (if) they start selling it without an included shock, you’ll have options.
One last benefit? Easy serviceability. Just clean the shock or pull it off for service, there’s no fork internals that need to be accessed. And if one of the parts breaks in a crash, you can just replace that one single part, not the whole fork.
They say they’ve subjected it to every UCI test, and it’s passed. They say it’s a lot stiffer than most, on par with a Rockshox Boxxer World Cup fork. And they’ve spent plenty of time trail testing it, running it into curbs and more. We’ll be getting one in for long term review to see how it works.
