Update: Shape-shifting 2021 Alchemy Arktos: The most versatile full suspension MTB ever?

Update: We now have information on what is required to convert between the different travel and wheel size configurations of the 2021 Alchemy Arktos. To convert your bike to a mullet configuration, you’ll need the mullet link available at $80. To upgrade the rear wheel travel, you’ll need an extender from Alchemy, which retails at $40. In addition to a new shock, of course.

Alchemy Bicycles have been drip feeding us teasers on the 2021 Arktos for months. After 2 years in development, they are finally ready to lift the lid on this shape-shifting full suspension mountain bike. No fewer than five different travel and wheel size configurations are confirmed:

• 29″ wheels, 130mm Front / 120mm Rear
• 29″ wheels, 150mm Front / 135mm Rear
• Mullet, 150mm Front / 135mm Rear
• 29″ wheels, 170mm Front / 150mm Rear
• Mullet, 170mm Front / 150mm Rear

We have the geometry figures on every single setup right here, plus how to convert between the different configurations, and pricing.

2021 Alchemy Arktos

All five of the 2021 Alchemy Arktos full suspension mountain bikes run the same full carbon frameset, despite their rear wheel travel options ranging from 120mm up to 150mm. Of course, they all run the same Sine suspension platform, so named due to the shock rate, which resembles a sine wave when graphed up.

The Sine suspension is now in its third generation form. Regressive through the first part of the travel to absorb small bumps and provide climbing traction, the suspension then becomes progressive in the mid-stroke to avoid wallowing on big hits or in hard, fast corners. It then becomes regressive again in the last 15% of the stroke so the bike can use all of its rear-wheel travel.

As they all use the same rear swingarm, each bike in the new Arktos range features 437mm chainstays, regardless of travel option or rear wheel size. A nice addition to the new frameset is space to carry two water bottles; one inside the front triangle and the other on the underside of the downtube. Here are the options…

Arktos 130/120

The short-travel Arktos is available as a 29er only, with 120mm of travel in the rear and a 130mm fork up front. The head angle sits at 66°, paired with a seat tube angle of 78°. Those angle are maintained across the medium, large and XL frame sizes, with only the reach, stack and seat tube length changing.

Reach figures are generous, starting out at 471mm in medium, stretching to 519.33mm in XL… that’s a roomy cockpit by most full suspension mountain bike standards, let alone a bike whose travel places it firmly in the trail bike category. The BB drops 40mm to a height of 333mm. 

The 2021 Alchemy Arktos 120/130 is available in three build kit options; SRAM GX Eagle ($5,499), Shimano XT ($5,999) and SRAM Eagle X01 ($6,399).

Alchemy Arktos 135/150

The mid-travel 2021 Alchemy Arktos gets 135mm of rear wheel travel married to a 150mm fork. This bike, and the long-travel version discussed later, is available as a complete 29er and as a mullet with a 27.5″ wheel in the rear and a 29″ wheel up front. The symmetrical 29″ wheel bike gets head and seat tube angle of 65 and 75, with reach figures stretching from 460mm in medium, up to 508.5mm in XL.

The Arktos 135/150 mullet mountain bike is slacker than its 29er counterpart, with head and seat tube angles coming in at 64.5° and 75.5°, respectively. Pricing for both wheel size setups starts at $5,699 for the GX Eagle kit, bumped up to $6,199 for the Shimano XT build, while the top-end X01 Eagle build will set you back $6,599.

Arktos 150/170

In its symmetrical 29″ wheel format, the 2021 Alchemy Arktos 150/170 sports a 64° head angle and a 76.25° seat tube angle. Reach spans a 452mm to 502mm range between medium and XL frame sizes, with the BB dropping 26mm to a height of 347mm. 

Its mixed wheel size sibling sees the slackening off of both the head and seat tube angles, which now sit at 63.5° and 75.75°, respectively. Reach figures remain identical while the standover increases massively. Pricing for both wheel size options starts at $5,999 for the GX Eagle build. The Shimano XT build will set you back $6,499 while the top-end X01 Eagle model comes in at $6,899.

Availability

Alchemy Bicycles are taking pre-orders for the 2021 Arktos now, with bikes available in May 2021. Frames are sold with a lifetime warranty. Get it in Charcoal/Sunburst, Gray/Light Gray or Sand/Burnt Orange colorways. Head to the Alchemy Bicycles website for full details on build specifications.

AlchemyBicycles.com