Arc8 extra st v1

When Less is More Extra ST - An Extra dose of fun

We built the Extra ST inspired by our local trails where it’s right at home. It’s riding on these trails where behind every corner a root is your potential take off, a dip waits to be manualled or a rut becomes your next berm. The Extra ST is an enduro bike condensed into a smaller package which unleashes the most fun out of those trails.

Where a trail becomes too dull on a bigger bike, it becomes a playground full of opportunities on this bike. The shortened travel injects a healthy dose of playfulness and efficiency. There certainly is a danger of going too wild on this bike. But in those moments, the Enduro-worthy geometry will have your back and guide you out of trouble.

You are wondering what category of bike the Extra ST belongs to? We don’t know either. But be assured, it is more fun than any of them.

Wheel Size
29"
Rear Travel
135 mm
Front Travel
140 - 160 mm
Frame Weight
2200 g
Sizes
S / M / L
Climbing
 
Rolling Trails
 
Technical Trails
 
Fast Downhills
 
Jumps
 
Arc8 extra st 7 Arc8 extra st 5 Arc8 extra st 4 Arc8 extra st 3 Arc8 extra st 2 Arc8 extra st 1

Tech Specs:

BSA BB

Creak free, easy maintenance, not fit issues - all our frames come with threaded BBs.

Internal Cables

All cables go through the headset into the frame. This does not only offer an exceptionally clean look, it also means the cables interfere less with your steering.

Reversed Main Pivot

The swingarm goes into the seat tube rather than around it, creating a very stiff connection. We are using Enduro Max bearings, specifically designed for MTB full suspension frames.

Designed for Carbon

We do not design our frame, and then give it to a factory to make it happen in carbon. Our frames are designed with the manufacturing process in mind from the start. Only like that we can ensure a carbon structure that can be produced with consistent high quality. While the focus in the development of carbon frames very often just lies on stiffness and weight, we also put a lot of effort into minimizing the chance of manufacturing flaws like voids, wrinkles or low compaction areas. This is absolutely critical to make carbon products not only light and stiff, but also durable.

Offset Rear Axle

When trying to combine 29 x 2.6 tires with good chainring clearance and short chainstays, there is just not enough room for the chainstays. Luckily now there are most cranks available with an even further outboard, 56 mm chainline without affecting Q factor. To get the cassette aligned, we keep using 148 mm hubs, but offset it 4 mm to the right, which provides multiple benefits:

  • More even spoke tension
  • Less exposed brake rotor
  • Weight savings over a 157 mm hub
  • You can keep your 148 mm wheels. Redishing them by 4 mm can be done keeping the same spoke lengths (theoretical difference is less than half a millimeter)

2.6" Tire Clearance

While lucky enough we did not have to go through that episode of ever shrinking "plus" tires, it left us with the great outcome that there is a wide choice of 2.6" tires. Many tests show it to be the fastest option, so making the FS160 compatible to it was a no-brainer.

Geometry

Longer, slacker, lower, with short chainstays. We are not going to repeat how that concept works, because you probably already heard it a thousand times since we designed the first 29er using it before people even knew what a long travel 29er is (it earned the "best geometry in the business" comment from Dirt Magazine back then). Just let us tell you, it still works. Something almost the entire industry gets wrong about seat angle is that the seat angle matters at the height of your saddle, not of your headset. Therefore, we measure our seat angle to an average seat height of 750 mm. You don't get that "theoretically ok, but in reality much too slack" seat angle that so many 29ers suffer from.

Geometry

Geometry enduro v1
Size S M L
Rider Height <172 173-182 >182
A Reach 447 472 497
B Stack 591 600 609
C TT 560 617 645
D ST 380 400 440
E SA 76.7 76.7 76.7
F HA 64.7 64.7 64.7
G HT 90 100 110
H Fork Offset 42 42 42
I Fork A-C (140mm) 551 551 551
J CS 430 430 430
K Wheelbase 1192 1221 1250
L BB Drop 35 35 35
M Standover 682 684 682

Frame Specification

Component Specification Comment
Headset IS52/40 | IS52/40 Compatible to FSA and Prestine Headset with internal cable routing
Seatpost ø30.9 150 mm Reverb can be fully inserted on every size
Seatpost Clamp ø34.9
Rear brake Postmount 160 mm
Rear Axle 148 x 12 mm Shimano E-Thru Standard
Max. Chainring Size 38 T with 56 mm chainline
Shock Size 230 x 60, 20x8/30x8 mm Hardware Fox bearing mount on link side possible
Fork 160 mm travel max.
Tires 29 x 2.6 max On 30 mm inner width rim.
BB BSA 73 mm
Chainguide ICSG05
Rear Wheel Boost (148 mm) rear hub, 4 mm offset
Bottle One 0.5 L bottle on down tube. Sideload bottle cage required