Alchemy

Arktos 27.5 Mountain Bike Frame

We're all pretty lucky in that we live in a time where there are plenty of great full-suspension mountain bike offerings. Materials, suspension platforms, and geometries are all so refined that only small subtleties separate most of the bikes these days. Still, certain brands are more popular than others, and you'll likely encounter the same bikes on the trails and at the races and the choices are pretty slim if you're after a boutique brand with full squish. That is, unless you're reading this and the Arktos 27.5 Mountain Bike Frame from Alchemy has you intrigued. This frame will build up a bike that's efficient for climbing and pedaling, with its innovative suspension platform, and the travel and slack geometry needed to tackle aggressive enduros, all aboard something a little more special than the mass-produced bikes while coming in around the same price-point.

Alchemy is a tight-knit group of designers, engineers, machinists, and painters. The company got its start in Austin, TX a decade ago but the call of the Rocky Mountains proved too much and the brand relocated to Denver, CO. All of its bikes are equal part art and technology and designed to last the long haul. Consistently in the mix as award-winning bikes, Alchemy quickly made a name for itself as a brand that caters to the most discerning cyclists. The construction processes and techniques on its frames are unique and are simply unachievable in typical mass-market manufacturing.

The Arktos 27.5 is a handmade in the USA carbon frame, an industry first and a favorite of cycling editors, people's choice, and shows awards internationally. To achieve this, it requires premium raw materials and the work of highly skilled craftsman to lay-up and cure the carbon fiber over several days.

The frames start life as carbon pre-preg sheets that are precisely cut on a CNC plotter of up to 500 pieces for a single frame. These pieces, specific weaving strands, and its dedicated lay-up process yield the bike's ride quality which obviously maximizes stiffness and minimizes weight. Those pieces are meticulously placed in CNC-machined molds that form the frame's individual tubes where bladders are placed within the carbon sheets and pressure is increased, molding the tubes during the baking process. After baking, the tubes are then mitered, placed in a frame jig, and tacked together with high strength epoxy. It's important to note that Alchemy frames come out of the molds so clean, it doesn't use epoxy as filler to make the frame look more cosmetically pleasing.

The frame then heads to in-house Ethic Paint Works to receive its award-winning paint job. Two layers of clear coat are applied over the carbon fiber, it's hand sanded, and the top coat paint scheme is applied. A final clear coat is applied over the color showcasing the carbon’s natural fibers, allowing the all-important, high-quality construction to be on display. The versions we have here are offered in a stunning Black/Orange or Black/Gold colorway.

Ok, now that we know how the construction is done, how does it ride? Thanks to its exclusive dual-linkage platform dubbed Sine Suspension, very, very well. Sine is the brainchild of bicycle suspension guru David Earle. David has over 25 years of experience in designing suspension in the cycling industry including working for many of the other mountain bike brands we carry. It gets its name from the shock rate, which resembles a sine wave as it moves through its travel. It starts off from its negative travel, i.e. through the sag point, with a regressive rate allowing for it to be plush off the top with small bump compliance while providing excellent climbing traction. Towards the middle of the stroke, it turns progressive and firms up to avoid wallowing on bigger hits and cornering. Deeper in its travel, at the last 15-percent of its stroke, it turns regressive again to overcome the natural progressivity of an air shock so you get all the 6-inches of travel you paid for and a plush, bottomless feel. Just like the frame construction, the devil is in the details, but the real magic happens when you throw a leg over the bike and hit the trails. You'll experience remarkable pedaling efficiency, thanks to its minimal chainstay growth, paired with the control of having 152mm of fully active suspension, even under braking, that gobbles up the terrain letting you ride faster and with more confidence.

The spec sheet on this Arktos checks off everything we like to see on frames. It has clearance for up to 2.4in rubber afforded by its Boost spacing that also helps stiffen up the frame's rear end and wheelset. A highly adjustable FOX DPX Factory rear shock handles travel duties offering a smooth, plush, and supportive stroke. The recommended fork length is 150-160mm with Alchemy's blessing to go all the way up to 180mm. We never hide our preference for threaded bottom bracket's as they are easier to install and ensure proper bearing alignment so the BB last longer and is less prone to creaks, pops, and moaning. It's also worth noting that the frame is designed for 1x drivetrains only. Build up your unique dream bike that'll get you noticed on the trails packing the technology, craftsmanship, and dedication that can only come from a smaller builder.