Atherton Bikes moves so fast that loads has happened since the brand’s first aluminium bike – the S170 – first appeared in the spring. One of the biggest changes being a move down the road to a new facility, where it can really ramp-up production and potentially glue together thousands of aluminium S bikes a year – if demand is there.

The Atherton S170 is a truly unique-looking prospect, with the construction method very much front-and-centre when it comes to the aesthetics.

The brand already has two alloy models without a weld in sight, in the newly-launched S150 and this longer travel S170, and when testing at Dyfi recently, I spotted another aluminium bike in development, but I’ll leave it to your imagination which A-series is getting modelled in metal next. All this to complement the existing additive-manufacturing options, of which the A.M170, I tested last year, I’d consider to be among the best enduro bikes on the market.

Whereas the ti/carbon AM. 170 has a sleeker, more rounded, and less divisive look.

I’ve written before about how the flagship carbon A-series Atherton frame are so complex and time consuming to make, but to reiterate, there’s a ceiling of 300 a year running just one Renishaw 3D printer to lay down the titanium lugs and hardware. Doing away with the additive Ti parts, and using slotted machined aluminium pieces to hold main frame tubes, not only gives the S-series its subtractive name, it means a big chunk of the work can also be subcontracted out to improve cost and efficiency.

7075 alloy tubes are bonded into double lap shear joints at the machined lugs. That means the tube is bonded both inside and out to the lug.

What’s key is that the brand identity and instant recognition remain intact, with the metal frames retaining the signature unique look and philosophy. The bonded construction model in both materials using different tubular sections affords loads of sizes, but the cost can be considerably less in aluminium, and the simpler frame should be even more rugged and reliable.

Obviously, the frame tubes, as well as lugs, on S models are aluminium, not carbon, and the two models available so far also use a more basic DW suspension layout to save further cash and complexity.

The S170 is available frame-only, or in three different build kits that are more affordable than the custom-built A models – yet still not exactly cheap. The frame alone is just under £2,800 (with a Fox DHX2 shock) and complete builds start at £4,800 for the cheaper RockShox Domain bike, up to £6k for the Super Deluxe/Zeb/GX Eagle version, with a Fox Performance-level bike inbetween for £5.5K. All models use a 180mm fork and Conti’s latest Kryptotal tyres with Hayes Dominion A4 brakes, mirroring the parts used by the race team of Charlie Hatton and Andreas Kolb.

The BB, main pivot, down tube junction is something else.

Design and specification

Like all its bikes, Atherton’s S170 is not only made in Machynlleth in Wales, it’s tested just up the road at the Athertons’s own bike park – Dyfi. It’s not exactly a bad way to do things either, driving five minutes from your HQ to a world class spot to test out new bikes.

The S170 takes direct inspiration from the A170 that was Dyfi’s main trail sculptor Dan Atherton’s personal bike project and manages to present something of the same low-slung look while using an older DW design, rather than the more tuneable DW6 layout that has an extra link behind the BB area and pivots on the chainstays.

With 12 frame sizes on offer, there should be an Atherton S170 to suit every rider.

You can read loads more about the S170’s build philosophy here and how it is being made from stronger 7075 T6 aluminium that isn’t suitable for welding, and follows the lead of the carbon version in terms of geometry and sizing. Atherton makes a big deal about finding the perfect fit, so S frames are offered in 12(!) sizes that grow in reach in 10mm increments from 405mm up to 515mm, while chainstays are size-specific too (to a degree). The bolted-together rear triangle extends from 430mm on the smallest four sizes, via 435mm in the middle, up to 440mm on the largest four sizes.

What’s also cool is the S170 rotating seat tubes on bigger sizes, so the effective seat angle goes from 76.6° to 78.6° to compensate for taller riders having more seatpost sticking out (and tilting back). The aluminium chassis uses a standard threaded BB and a SRAM UDH derailleur mount for ease of servicing and parts sourcing.

Larger frames get steeper seat angles, but Atherton Bikes could spec a longer dropper post.

As well as being sent through some of the biggest jump lines in Europe, the S170 is also tested independently at EFBE in Germany for fatigue, max load and overloading. Like other bikes Atherton sells, it passed the rigorous Cat 5 (downhill) standard, but one thing that’s changed since the bike I rode in the spring, is the seat tower junction being beefed up, which proves that despite how much testing you do, out in the real world brands are continually learning; in this case from a few frames in the wild that had an issue.

Atherton is keen to point out that, even though the S170 has tons of brute strength and a DH-rating, it doesn’t come at the expense of a tuned ride feel. The aluminium chassis went through multiple rounds of prototyping to try and match the A170’s flex characteristics (especially in the rear triangle). This latest version is quite flexible to touch; you can even twist by hand the L-shaped seat stay that hides the rear cables on its inside edge when handling the frame on its own.

While the A bikes use a 6-bar DW-Link design, the Atherton S170 gets a simpler twin-link DW4 layout.

A couple of points stand out in terms of looks. The squared-off cage that cradles the shock at the lower end and BB junction is pretty funky, and there are also more angular and sizeable lugs/joints here compared to the A-series carbon bikes. Frame protection and chainstay padding is less substantial than many similar competitors too, so the S170 isn’t totally silent, and while it’s a small detail, I did notice a tiny amount of bonding agent visible in places where it oozes out of the frame’s lap shear joints that sandwich the tubes.

Atherton Bikes has spent a long time tuning the ride feel of the frame to get the characteristics it desires.

Suspension and kit

Across the three S170 tiers, there’s RockShox Ultimate or budget suspension, and also Fox Performance kit. This time out, I also tested a special ‘Team Edition’ set-up built around the frame-only with Fox Factory-level suspension plugged into the S170’s DW-Link frame.

Yep, that’s right; while the A-series bikes use a 6-bar DW6 configuration that’s unique to Atherton, the short twin-links here are the same DW-Link design that’s been around for decades and used by Pivot, Ibis and others (remember the Iron Horse Sunday?), but obviously, like any suspension lay-out, the devil is in the detail.

The Fox-equipped bike Mick rode felt better optimised than the RoxkShox model.

Atherton is unusual in being guarded about what these details actually entail, and doesn’t publish the usual graphs and charts showing leverage rates, anti-squat and anti-rise that most other brands do. When pressed as to why, it turns out the suspension curves and pivot point set-up is done directly by Dave Weagle (the inventor of the DW Link) himself, and that’s the way Mr Weagle wants it.

Not the slickest bit of frame protection, but it works.

Both the lower link and upper triangulated rocker link rotate in the same direction and drive a Trunnion mount shock that’s 205mm long and has a 65mm stroke. At 85kg, I used a 550lb spring on the Fox DHX2 and around 100psi in the Fox 38 fork.

Amongst the different builds, none of the S bikes compromise on tyres or brakes, with excellent Hayes Dominions that have tons of power and a light lever feel, but there are still a few weird bits and pieces here such as a 180mm rear rotor and shorter-than-possible dropper post (especially considering the seat tube is totally uninterrupted, so nothing in theory is stopping running something longer). The frame also comes with water bottle bosses and has decent tyre clearance.

No one will miss you riding an Atherton S170.

Testing notes

In order to put the S170 through its paces with a relevant reference point, and because Atherton weren’t keen on directly comparing with the more expensive A170, I took a Propain Spindrift I’ve been testing down to Dyfi. My friend and fellow test rider, Christopher Sutcliffe, helped out, and while he’s much taller, we conveniently both weigh almost exactly the same, so it was easy to switch back and forth and ride the same tracks without having to adjust anything.

Propain’s latest Spindrift was used as a comparison benchmark.

The Spindrift is a lot more expensive, but the basic ‘super-enduro and bike park’ remit is the same, and Propain sells carbon models with equivalent specifications for much the same cash as Atherton. The Spindrift frame also costs less on its own. Pricing aside, the two bikes are wildly different in how they go about things, so how does that translate in terms of ride quality?

No place like home – the Atherton S170 in its natural habitat.

Performance

Obviously, at an uplift bike park, you don’t have to do miles of climbing, but there are plenty short, sharp inclines at Dyfi when switching about between tracks and zones on the mountain. It’s here, where I would crank uphill or sprint along the flat, that I got a decent feel for pedalling manners.

Built to last – the cat 5 frame rating is backed up by a lifetime guarantee.

It’s almost unfair to directly compare the S170 to Propain’s Spindrift, as that latter is lighter and also one of the most efficient and neutral-pedalling long travel enduro bikes I’ve tested. Fortunately, the S170 still totally holds its own, despite being almost 1.5kg heavier at 17.4kg.

Atherton’s DW Link has a pedalling action that’s direct, without too much bobbing or wallowing, and each crank stroke transfers power into drive at the rear tyre without bogging down in the mid-stroke or pulsing excessively as the cranks turnover. Basically, as 170mm bikes go (especially with the ease in which the back tyre gets out of the way of bumps and obstacles while climbing), I’d rate the S170’s pedalling as perfectly acceptable, and even at the slightly more efficient side of things compared to many big travel rivals.

When the light catches the S170’s alloy frame, it’s a beautiful thing.

The aluminium bike’s extra weight is noticeable to pull uphill, but after trying the bike with both Enduro/Soft Conti tyres and DH/Super Soft, the tyres make a bigger difference in terms of rolling speed. Unless you plan on doing lots of mileage, my choice would still be to suck up the extra resistance in favour of greater grip considering this is a bike that’s clearly optimised for the kind of riding Dan Atherton and the Dyfi get up to. Specifically ‘race-pace laps to braking bumps, huge jumps, flat landings and a lot of cases’.

It’s this kind of riding that this bike was born to do, and its descending performance and character in this department couldn’t be more different from the Propain. Where the German rig calms everything down and stays so balanced there’s almost an aloof and detached vibe, the S170 offers a really visceral and direct connection to trail features and terrain.

Point and shoot – the S170 is more dynamic than its 17.4kg weight would suggest.

The S-170’s coil-sprung rear end is pretty smooth off-the-top, and the bike seems to move and pulse to the rhythm of the trail, being eager to dip in and out of the shock’s stroke. I found this was still the case even when I dialled in more low and high-speed compression damping.

The RockShox Super Deluxe bike I tested previously was arguably slightly over-damped, and my guess that the S170 had been tested and set-up with a Fox shock still holds water after riding that combo. The back end is more fluid with the Fox, and uses a lot of the travel quite easily, especially compared to the Propain, where everything is duller and more controlled in comparison.

And it climbs well for a heavy bike.

This sensation does make the S170 very exciting to ride, and there’s an impression of impressive tracking at the back tyre. The MX-wheeled bike is also really reactive and fast turning, so I could chuck it around like a shorter travel bike, despite that deep-feeling travel. Chris and I both agreed that the Spindrift is much less hectic and more muted when riding faster, but also that it sits a lot higher in its travel and rides like it has a taller BB, so it’s gives less confidence when tipping from side-to-side and slashing through linked turns. The S170 also has a more rearward weight bias that had both of us swinging off the back a bit, so there will be a bit of rider preference as to what kind of feel you’re after.

One negative of the S170 being eager to move through its travel and munch bumps is that this plushness can lead to the back tyre drifting away and breaking traction. My thought here is that, because my weight was less stabilised, it shifts further back mid-turn or while carving up a lip face. In these scenarios on the same tracks, the Propain always kept my rider weight higher and more neutral, but it didn’t have the same feeling of springiness, or the ability to load it up and bounce off long lip faces and berms.

Not quite as polished as the A170, but the Atherton S170 still rocks.

I read back through my first impressions of the S170, and while it feels quite different with the more active Fox shock (with the same spring rate as the RockShox I tried), I stand by what I said about the aluminium Atherton feeling like a race car with a bucket seat and my bum skimming the deck. A sensation will only get stronger with a 27.5in wheel up front and a 26in wheel out back – a configuration that the brand suggests is possible for pure park rats.

There’s a real stiffness and solidity at the S170 front end, and it feels like the frame has most of its compliance between the BB and the rear axle. Overall, it’s still not as smooth and doesn’t isolate from small bumps and chatter as well as the high-end A170 I’ve tested, or the well-damped Spindrift, but it’s arguably easier to access a more intense and engaging ride experience than it is on the Propain – a bike that I really needed to charge on to fully light up.