Specialized S-Works Epic 8 review

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The new Specialized S-Works Epic 8 is one of the most technologically advanced mountain bikes on the market, dressed in a full suite of SRAM and RockShox wireless gadgetry.

The bike has had a complete refresh, with a new frame, revised geometry, updated suspension kinematics and fresh parts package.

Following the launch of the 75mm-travel Epic World Cup bikes, it’s no surprise the Epic 8 now sees 120mm of travel front and rear, designed to race the gnarliest cross-country (XC) tracks around.

The bike has been co-launched with RockShox’s latest iteration of Flight Attendant – the electronic suspension-damping control system. This means the Brain system, long synonymous with the Epic, has gone.

After thorough testing, I’m confident in saying the new Epic is even better than ever. The revisions amplify the bike’s performance and Flight Attendant (only available on this top-spec model) is a worthy replacement for the Brain.

However, if you want this benchmark XC race bike, you’re going to have to be friendly with your bank manager.

Specialized S-Works Epic 8 frame and suspension

Being an S-Works frame means this model is treated to Specialized's top-spec 12M carbon fibre – a higher-modulus material than the 11M fibre found in the Pro models and below.

The use of 12M carbon saves weight for a given stiffness and ride quality.

The frame has been built with ride quality in mind, with Specialized’s engineers ensuring it’s not too stiff – being so would induce extra fatigue, which helps nobody go faster.

The frame’s forward shock mount is now part of the front triangle from the off, thanks to a new bladder-moulding technique, rather than it being effectively stuck on as before.

This saves weight, because there are continual fibres running through the frame and the shock mount, meaning the area’s strength (and therefore weight) doesn’t have to be bolstered.

Other features of the frame include a steering block to prevent damage from the fork in a crash, frame-protection bumpers on the down tube and chainstays, a grommet to prevent dirt and water ingress between the front and rear triangles, and internal routing for the single rear-brake hose, which is routed through the headset.

There’s also the SWAT 4.0 door. This has a new hinge-and-lock mechanism that’s smoother and well-sealed. CO2 canisters and tubeless plugs can be stashed on the underside of the door itself for quick and easy access. The frame has space for two water bottles.

Simplified suspension

The 120mm of rear suspension is controlled by the now de rigueur flex-stay system – this single-pivot, linkage-actuated shock design relies on flex in the rear seatstay to help control the suspension’s feel. It’s a design found in most new XC race bikes these days.

It’s lighter and less maintenance-intensive than a traditional rear pivot, hence its popularity.

The suspension’s kinematics have been developed on this generation of the Epic. Specialized’s engineers claim there’s 20 per cent less pedal bob and a 12 per cent increase in the suspension’s ability to absorb impact forces.

What is noticeable about the Epic 8 is the lack of a Brain cartridge linked to the shock and fork. It's a huge departure for Specialized.

On this S-Works model, the new Flight Attendant system from RockShox takes its place.

Sensors in the fork, shock, power meter and drivetrain contribute to the system’s processor deciding which of three low-speed compression modes the fork and shock should be set to, while servo motors switch the damper between modes in an instant.

The system’s Bias settings enable you to tune how aggressive, or mellow, you want the system to be.

A higher bias (＋1 or ＋2) will make the system favour what Specialized calls ‘Magic Middle’ or ‘Sprint-On-Lock’ modes more readily, when you put harder cranks in, head uphill or encounter smoother terrain. The -1 or -2 modes will move the system back towards ‘Wide Open’ earlier.

When the batteries run out or the system is turned off, it defaults to ‘Wide Open’.

On non-S-Works versions of the Epic, the three positions are selected via an on-bar lockout.

Both fork and shock have a digressive ‘Magic Middle’ mode. Under pedalling forces, pedal bob is tuned out, however when an impact is driven through the suspension, the digressive nature is said to enable the suspension to absorb it, while also enabling more suspension travel to be used for a given bump size.

Both of these factors contribute to the claims about pedal efficiency and bump absorption.

Specialized S-Works Epic 8 geometry

Five sizes of the Epic will be offered, from XS to XL. At 182cm tall, I rode a large.
The geometry reflects the ongoing changes in XC, with longer, lower and slacker frame shapes starting to dominate in order to make the bikes fast over technical terrain.

The Epic has a head angle, in its low setting, of 65.9 degrees – a figure seen in more aggressive trail bikes a couple of years ago.

This is paired with a seat angle of 75.5 degrees (the XS and S are 76.5 and 76 degrees respectively), which is fairly steep for an XC bike.

Wheelbases are long, thanks to the slack head angle and the roomy front end, with the reach on a large 475mm.

A 450mm seat tube allows for a long 150mm dropper post to be fitted.

Specialized S-Works Epic 8 specifications

When it comes to the specifications, the big story is clearly the RockShox Flight Attendant system integrated into the suspension and drivetrain.

As mentioned, this controls the damping mode of the fork and shock to, in theory, match the terrain you’re on and the effort you’re putting in.

The most noticeable indications of the Flight Attendant system are the units on the fork and shock body.

However, they also link to the 34t ring Quark power meter crankset and your gear selection.

Combining this data with the gradient, as well as machine learning from your previous seven rides, enables the system to pick its mode. The AXS app then helps you tune the system’s response.

At the bar, things are very tidy, with a pair of SRAM AXS Pods on either side. These control the XX SL Eagle AXS Transmission and Reverb AXS dropper post, and provide an override to the Flight Attendant (the app enables you to select which mode the override puts the fork and shock into, and for how long).

SRAM dominates the bulk of the build, with the 120mm RockShox SID fork and SIDLuxe shock (with custom damping internals), the XX SL drivetrain and Level Ultimate four-piston brakes.

Elsewhere, Specialized provides its Control SL carbon wheels, with a Renegade rear tyre and Fast Trak front, both in 2.23in widths, as well as an integrated bar/stem cockpit and saddle.

All in, you’re looking at 10.6kg for a size large.

Specialized S-Works Epic 8 ride impressions

I attended the launch of the Epic 8 in Matanzas, Chile, in late 2023. The two days of riding there were fast and furious, on hard-baked, dusty ground.

While the tracks weren’t technical, they were great to test the limits of grip, along with how well the bike coped with being thrown off ladder drops, through berms and off some step-downs.

I then got hold of the bike in the UK, enabling me to give it a proper test on familiar tracks in typical British winter conditions – wet, rooty and steep.

To set up the suspension, it’s simple to turn the Flight Attendant units to their Wide Open mode. In doing so, I set the rear sag to between 25 and 28 per cent, depending on conditions. I set it harder in the faster, drier conditions to give the bike plenty of zip and a touch softer in the UK, to help keep things forgiving.

Tyre pressures were set moderately low – around 22psi at the front and 24psi at the rear. The wide rims (with broad rim walls) enabled me to get away with such pressures on a lighter-weight tyre.

Pre-launch, the RockShox Flight Attendant app wasn’t available for my Android phone, though we're told it should be now the bike has launched officially.

However, during the launch event, I was able to set up the override mode – it’s easy to set the bias setting too – without the use of the app.

I played around with the bias, with different modes suiting different rides. The neutral mode feels the most useful, but adjusting it is easy, anyway.

With the system learning how you ride, it takes a little time for it to hone in on your inputs.

For example, on my first ride on the bike, I was told to ensure I completed at least three high-intensity sprints for a minimum of 20 seconds, as well as medium- and low-intensity periods of pedalling.

The system analyses your previous seven rides continuously, to help fine-tune its performance.

However, it will discount rides that are clearly outside your normal use – for example, riding from your vehicle to the pits, or bouncing around in the streets practising your wheelies.

Specialized S-Works Epic 8 climbing performance

There are a number of facets that help or hinder a bike when it comes to climbing and the suspension is one of the biggest.

Another major consideration is the wheel and tyre setup, and Specialized has good form here.

The Renegade tyre on the back is light in weight and has fairly closely packed, low-height tread blocks.

This leads to a tyre with low rolling resistance and when mounted to a light carbon rim, it spins up to speed easily, giving the bike a decent level of zip.

The tyres hold their speed on smooth surfaces, and on rooty, rocky tracks, the sidewalls conform well to the ground, while the T5 rubber compound does a pretty good job of gripping while not being too sticky and slowing you down.

That said, here in the UK, it’s no surprise the shallow blocks don’t cut into mud particularly well, leaving you spinning out.

If you’re spending this much on an XC race bike, it’s likely you’ll have some winter-friendly tyres knocking about, or the budget to buy a set of the best mountain bike tyres.

SRAM’s Transmission works exceptionally well. I’m not a huge fan of the shift delay – the system waits for the chain to be in the right place over the cassette’s shifting ramps before the derailleur pushes the chain from sprocket to sprocket, inducing a delay between button push and gear shift. However, when it does so, it's with minimal complaint, even when you’re pushing some serious power through the cranks.

Being SRAM, it works smoothly when grimy, and doesn’t rust up particularly quickly, either.

The angles of the bike work well uphill. The seat angle’s steepness feels good on prolonged ascents, and with the bike sitting pretty high in its travel a lot of the time, the angle is preserved on steeper pitches, too.

Supreme suspension

The main evidence is via the suspension.

Ignoring the automatic damper control for a minute, I feel the engineers have done a pretty good job of the shock tune.

The lockout is firm, so when you’re pedalling hard on smooth surfaces, all your effort goes into driving the bike forward.

The chassis is pretty stiff from side to side, too, so the Epic 8 doesn’t feel as if it’s throwing your effort away.

In the Magic Middle, the mode the engineers have worked on with SRAM to develop a custom digressive tune via a bespoke set of shock internals, things are equally competent.

The bike doesn’t lurch horribly deeper into its travel under pedalling loads and it stays around its sag point nicely.

When you do bump into a rock or root, there’s enough suppleness to help ease the wheel over without spitting its dummy out. It's rare that it wallows into its mid-stroke.

Does Flight Attendant work well on the climbs?

In short, yes, but it’s not perfect.

The system shifts you through the various modes, usually toggling between Lock-On-Spring and Magic Middle, depending on the circumstances – gradient, gear, effort and smoothness.

The physical and audible clunk of the old Brain system is gone, replaced with an electronic zip, as the servo motors do their job.

The system tends towards the shock being in a stiffer mode, if there is a difference – the fork might be in Magic Middle while the shock is in Sprint-On-Lock, and this makes sense.

It’s not infallible, though, because the system is reactive rather than proactive.

At times, most notably when transitioning from a descent (where the dampers will tend towards being more open) to a smoother climb, it takes a few pedal strokes to sort itself out.

Here, on occasion, I found myself pedalling hard on a bike that was at first open, before moving through Magic Middle and into the firmest mode, with a noticeable bit of pedal-induced bob in that early transition when you’re pushing hard at the pedals.

On a bike without Flight Attendant, you'd be able to preempt the need for a lockout quicker.
However, if this becomes a noticeable issue, the override button on the left-hand shifter pod can be earmarked to shift the system into Sprint-On-Lock, should you wish.

Specialized S-Works Epic 8 descending performance

With a head angle of less than 66 degrees, a reach longer than some trail bikes in 2024, a 150mm dropper and a 35mm chassis fork at the front, it’s no wonder that, so long as you can keep the tyres under control, the Epic 8 descends really well.

The long front end gives the bike plenty of stability and confidence in steep and loose terrain, while the relatively stubby nature of the all-in-one cockpit’s stem ensures steering responses are still snappy – something the XC crowd will always appreciate.

The front end is lower than you’d find on most trail bikes, especially with the flat bar and 610mm stack, but despite this, the 778mm front-centre helps prevent you feeling you’re going to tip over the bars.

SRAM’s four-piston Level brakes handle decelerations well, though on the longest and steepest descents on my test loop, I started to cook the rear. Outside of that, it's great having confident stoppers to rein the speeds in.

At the front, the Fast Trak tyre works well in dry conditions. It rolls fast, while the 2.35in width on the broad Roval rims gives them plenty of volume, to help tune out fine chatter and take some of the edge off the sharper hits.

They are rounded tyres, though, so in loose, muddy conditions, you still need to take care of directional control.

I like the Roval Control SL wheels. They have a really broad rim wall to help dissipate impacts and they’re pretty comfortable, too. That said, when you really push them in high-load situations, you can feel them twist and twang a bit.

The suspension works well. The SID fork is stout, smooth and seems to hug the ground nicely.

It also has the digressive Magic Middle mode tune, which helps keep the fork stable under pedalling loads, but still offers comfort and support.

At the rear, it’s noticeable that in this Magic Middle mode, there’s a firmness.

On fast, flowing terrain, this helps you pump the bike, generating speed, at the expense of a little overall smoothness.

Hit those bigger bumps though, and if Flight Attendant feels Magic Middle is still the place to be, it enables you to use much of the travel on offer, thanks to that digressive tune.

For the most part, assuming there are some lumps and bumps along the way, the system errs towards Wide Open, unless you’ve gone really aggressive with the Bias modes.

Here, the fork performs as we’ve come to expect, while the rear end displays high levels of control, with a smooth transition through to the end of its travel on the biggest hits.

As when climbing, Flight Attendant tends to get the mode right, in my experience.

Perhaps the most notable example of how effective the system is was displayed on a smooth, flowing bit of singletrack that led into a drop, which I rode a number of times.

On the singletrack, the system was in Magic Middle, giving me the platform to push against (in the non-Flight Attendant bikes, Specialized’s engineers expect you to spend around 80 per cent of your time in the Magic Middle mode). However, during the brief freefall to the landing, the system audibly opened up into Wide Open, pre-landing.

You can simulate this off the bike by lifting the front wheel up and then slamming it towards the ground – the transition to Wide Open is impressively fast.

Looking away from the high-tech parts, I have to admit to loving the S-Works Power saddle, though I would probably leave the Roval Control SL integrated cockpit.

With no option to roll the bars, or swap stem lengths, it’s compromised in terms of optimising your setup (something I feel is important on such a bike at this price), and I’m yet to find an integrated cockpit that’s as comfortable on long rides as a separate system.

On marathon-type rides, comfort is key, even if this setup offers the stiffness pro racers want when hauling at the bars.

How does the Specialized S-Works Epic 8 compare to the Specialized S-Works Epic World Cup?

If you want to go fast in XC, and want that exclusive S-Works logo on your down tube, you’ll be picking between these two bikes.

The Epic World Cup comes with 75mm travel at the rear and 110mm at the front, with the SID SL Ultimate fork featuring Specialized’s Brain damper. This is a mechanical auto-lockout system featuring a spring-loaded inertia valve.

At the back, three suspension modes are offered via an adjustable negative air spring that alters the amount of sag (from 0 per cent to 10 per cent) and ride feel.

The Epic 8 is the more versatil bike. The additional travel ensures it can be rallied over pretty much any terrain with plenty of confidence.

With both fork and shock sitting into their travel, the bike feels nicely balanced and Flight Attendant ensures it feels efficient under power.

The Epic World Cup has a very focused demeanour. It’s a very fast and light race bike, which, though still capable, feels as though it has its limitations on more technical terrain.

The rear suspension blends the feel of a hardtail and full-suspension bike nicely, but can leave you rattled when pushing on over gnarlier tracks.

On steep descents, the World Cup’s limited travel and sag pushes your weight further forward, leading to a more nervous ride.

However, when the trail points back up, the World Cup is a mountain goat, with pin-sharp reactions to pedal inputs and, in my experience, tons of traction.

To sum up, the Epic 8 is hugely versatile – from full-gas race efforts to smashing fun laps around your local trail centre. The Epic World Cup is a highly focused race bike that’s best suited to punchy and yet technically mellow courses.

Specialized S-Works Epic 8 bottom line

This is the easiest bike I’ve ever ridden and there are several reasons I say that.

First up, there’s no doubt fast-rolling tyres and efficient suspension systems make for fewer watts being wasted, helping you either put less in or get more out. Add in climbing geometry that puts you in a solid position over the bike and the Epic 8 is a great basis for going uphill.

When it comes to the descents, the geometry, again, takes a bit of beating in an XC context, helping you maximise your gravitational potential.

The SID fork has a great chassis, the wheels are comfy and the brakes on-point. The 120mm of travel simply makes sense these days.

But it’s the Flight Attendant system, and to a lesser extent, Transmission gearing, that puts the cherry on top.

By removing the need to consider which suspension-damper mode you should be in, and by removing the need to twist a barrel or push a lever, the reality is all this tech, though expensive, goes a long way to removing some of the mental load that comes from high-pressure race situations.

Flight Attendant shifts the damper mode far more frequently than you’re likely to, without you needing to get involved, while the ability of Transmission to shift under virtually any situation means you don’t have to back off or time your shifting to be mechanically sympathetic.

Combined, this gives you more time to think about your racing than what your bike should be doing.

Yes, this is super-expensive tech and this S-Works Epic 8 is targeted at elite racers, who’re most likely to benefit.

However, it's good that these halo products exist because, in time, the tech may well trickle down to more affordable levels. And when it does, I’ll consider buying it for my own bike.