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

2021 alchemy arktos todd renwick action shot
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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

2021 alchemy arktos action shot

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.

2021 alchemy arktos sine suspension platform 3rd gen

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

2021 alchemy arktos short travel 29er

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. 

2021 alchemy arktos 130 120 travel geometry chart

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

2021 alchemy arktos 29 150-135The 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.

2021 alchemy arktos 135/150 mid travel mountain bike geometry chartThe 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. 

2021 alchemy arktos long travel

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.

2021 alchemy arktos geometry chart

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

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esc8engn
esc8engn
3 years ago

there is a lot i like, and admire about alchemy, and their designs. i almost want one.
but i can’t believe that lower downtube shape is sacrificed for a mere bottle spot. is there another advantage to that underbite? it looks like a log puncher of a frame to this new englander.

allan
allan
3 years ago
Reply to  esc8engn

With you on that, the last version was gorgeous. The lines on the new bike are awkward

Andrew
Andrew
3 years ago
Reply to  esc8engn

To each his own…

…. Where I am, having at least 1 (if not 2) bottle mounts is almost a necessity. Yes you can carry water in a camelbak, but here we need bear spray close by. On my RM Element one bottle cage has a water bottle, and the other a can of bear spray at all times!

PaulM
PaulM
3 years ago

“how to convert between the different configurations”
Which is?

Deputy Dawg
Deputy Dawg
3 years ago

Shouldn’t the longer travel 29er have the steeper STA?

K
K
3 years ago

I picked up the 2021 Arktos 150/135 and it’s been killing it on my local Tahoe trails (I most recently rode a 2018 Stumpjumper and many others before that). The geometry is perfect. Alchemy hit the sweet spot where it climbs amazingly – SO much better than my Stumpy which often had a wandering front wheel despite my many adjustments to the stem and saddle – while still having a slack enough head angle to be super confident in the downhills (75 degrees). I looked at a lot of bikes before I pulled the trigger on this, specifically looking at geometry for my long-ish torso while also assessing the bike’s climbing ability since I like to earn my turns. Compared to my Stumpy and other bikes I tried, you sit IN the Arktos instead of ON it – ideal for me. I was between an Ibis Ripmo and the Arktos and am super happy with my choice. Get a lot of compliments, too. Only thing I’ve changed is the saddle (of course) and swapped the back DHRII to an Aggressor.

Simon L
Simon L
2 years ago

Been riding mine (135 mm large) everyday for 2 weeks it pedals like a yeti: the rear wheel doesnt hang on anything it just gets out of the way of rock and roots while pedaling. You can aim at a rolling rock pedaling up and the rear whell goes over it without the rebound quicking you up or the stone moving its very unique. Its very stiff and rather low bb with 30% sag great for cornering but I do a bit of pedal strikes. I tried to put more air but the bike doesnt sit in its sag with too much air and bobs more. 30% sag works well for me. Im very pleased with it, Replaced the heavy tag stem end handlebar, changed the crappy saddle, removed the tubes and put on the valves that came with the package and its now 31 pounds and a notch with pedals and the very heavy assegai dhr2 combo making it average weight id say. I love how it handle manual, its kinds of sits in the manual position very easily the wheel movement does an extra help. Its a supportive and playfull bike to ride. The low offset fork make the steering a bit harsh at low speed and the bb beeing a little low is the only thing that needs a bit more attention the rest performs over my expectations. I like to ride without any backpack so the water bottle room makes sense for me but it does make the bike looks less awesome especially without the bottle. Hydra hub is a big plus too.

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