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2015 Specialized Demo 8 S-Works Carbon 650b (discontinued)

Vital Rating: (Outstanding)
2015 Specialized S-Works Demo 8
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First Ride: 2015 Specialized S-Works Demo Carbon

Rating: Vital Review

Review by Brandon Turman // Action photos by Dave Trumpore

Surely you’ve seen Specialized’s new spaceship S-Works Demo 8 Carbon by now. The thing is missing half the seat tube and looks more akin to the concept bikes of the future than to something you’d find at your local bike park. Troy Brosnan and Aaron Gwin also piloted it to three World Cup podium finishes after it was introduced late this season, as well as third place at World Champs. Well, this coming January the future will officially arrive at Specialized dealers around the world. Curious how the alien-looking rig rides, we saddled up for two days of rock, root, and berm bashing fun in Whistler, British Columbia.


S-Works Demo Carbon 650b Highlights

  • 650b (27.5-inch) wheels
  • 200mm (7.9-inches) travel
  • Full FACT 11M carbon frame
  • RockShox BoXXer Team fork with Charger Damper
  • Custom tuned Öhlins TTX22M rear shock
  • Asymmetric seat tube design
  • Internal cable/brake routing with guides or optional external brake routing
  • 1.5-inch headtube
  • 83mm BB30 bottom bracket
  • Molded chainstay, seat stay, and downtube guards
  • Unique 12x135mm “L7” square rear axle
  • 63.5-degree head tube angle
  • 343mm (13.5-inch) bottom bracket height
  • 430mm (16.9-inch) chainstay length
  • Frame weight: 7.6 pounds (without shock or protectors, size Medium)
  • Short, Medium, Long, and X-Long sizes
  • MSRP: $9,000

If you somehow missed the basics, let’s recap some of the finer details before we dive into how it performs:


Where the did the seat tube go? What on earth were they thinking? While it may look like an art project gone wrong to some, Specialized claims the design saves weight, lowers the center of gravity, and also allows for easy access to the Öhlins TTX22M rear shock. How often does one really need access to the shock though? If you’re racing at a highly competitive level, potentially every race. If you’re a set-and-forget rider, likely a lot less. We found it handy when swapping shock springs to find that perfect sag point.


Kinematically the old and new Demo have virtually identical suspension by several common measures, including anti-squat (there isn’t much), pedal-kickback (almost non-existent), and brake-squat (very low). Though the new design is ever so slightly more progressive, even the leverage rate curve is practically the same. So why make an entirely new bike and not switch things up? Clearly they didn’t think they had much to improve in this area, backed by their own tests of dozens of new suspension designs with lots of emphasis on momentum and braking response.

According to Specialized, the big reason for the change was to lower the center of gravity. They did this by lowering all pivots by three inches. They also used the opportunity to kill off the “extra” stay the old Demo was often mocked for. The updated FSR suspension design utilizes a concentric main pivot at the bottom bracket with 50mm diameter bearings and one big axle that threads in. Thanks to larger bearings in all the pivots, the 2015 Demo sees just 1/3 of the friction in the linkage compared to the previous frame.


Öhlins is still up to bat in the shock department, and once again the twin-tube rear shock has been tuned specifically for the frame, eliminating unnecessary clicks from the compression and rebound adjustments. Internally they’ve reduced mid-speed compression for more control on initial hits, and increased high-speed compression for more control when at the limit.

Believe it or not, the rear end is actually torsionally stiffer than the previous design thanks to the use of carbon, bigger pivots, bigger bearings, and a new "L7" square 12x135mm axle design. During an early prototype stage Aaron Gwin actually said it was too stiff and Specialized adjusted things as a result.


The new "S3 Geometry" system is short for "Style-Specific Sizing," where the length of the bike and corresponding ride characteristics are the deciding factor. Short, Medium, Long, and X-Long sizes are available with similar seat tube heights. The geometry includes a 63.5-degree headtube angle, 343mm bottom bracket height, and 430mm chainstays. Compared to the 2014 Demo, this new version has slightly longer chainstays, a longer wheelbase, and longer reach across the size range.

How does this all play out on the hill? Time to find out...

On The Trail

Whistler Bike Park gets a lot of play these days, and for good reason. It’s incredible. The place offers everything a bike tester could hope for. There’s rough and rowdy, steep and tech, fast and flowy, and jumps so big they scare away all but the most experienced riders. From the lofty hits on Crab Apple and Dirt Merchant to the steep puckerfest of Goat’s Gully, we rode it all aboard Specialized's new steed.

At 5'10" tall, our lead test rider, Brandon Turman, often finds himself between sizes. Sometimes the Medium is best, other times a Large. Considering the new sizing scheme, he opted to spend one day on the Medium and one day on the Long. Both were set up with identical tire pressures and spring rates yielding ~33% sag while seated.


After nearly twenty laps in the park, our overriding impression is the same one that hit us just a few hundred feet into the first run - the new Demo is incredibly quiet, controlled, and composed. While the roots and rocks beneath you may be out to eat your lunch, this bike finds a way to calmly glide over the tops of them and send you on your way with your wits still about you. Confidence inspiring? You bet.

The lack of surprise moments encourages you to try new lines and begs you to ride it harder. We found ourselves bounding across rooted sections that previously tripped us up, all the while retaining full control. In that quietness at the bars you’ll find instant comfort, and as a result your speeds can and will increase. Those new fangled 650b wheels no doubt contribute to the speed and handling in rough situations, but the sum of all the small frame details improve the ride in a way that simply increasing the wheel size never could.


The bike’s geometry only adds to the fun with a head angle that says, “bring it on,” short chainstays that keep it playful, and a low bottom bracket that aids immensely in corners. When you lean it over you feel very much like you’re in the bike, and the resulting traction is incredible. Chassis stiffness and responsiveness left nothing to be desired, even through rough turns.

That ultra low bottom bracket takes a little getting used to, however, just as it did with the original Demo. When you aren’t able to coast, you had better time your pedal strokes perfectly. This isn’t helped by the extra material at the ends of SRAM’s X0 DH carbon cranks, so Specialized specs 165mm length cranks across the size range to compensate. Unexpected ground contact made for the only scary moment of our test ride, so we could see some riders swapping the cranks out for something with more clearance. We even hit the cranks on flat ground when sprinting into jumps on a few occasions, despite running proper sag and a healthy amount of low-speed compression.


For the most part, suspension performance was as expected and similar to the previous model. We spent a fair amount of time riding wet roots, and despite the somewhat questionable Specialized Slaughter rear tire choice, traction was impressive. The rear end seemed very supple, no doubt aided by the new bearings on the Öhlins shock and reduced linkage friction. Big hits routinely used full travel but the bike never bottomed harshly, which left us stable and in control. The preset high-speed rebound was just where we’d like it, with no issues exiting turns, g-outs, or leaving jump faces.

After two days of testing, we had two just reservations with the suspension. First, we felt as though we were diving through the travel going up big jump faces, and this feeling wasn't alleviated by cranking in the low-speed compression all the way. Second, we experienced spiking on two occasions while charging through the rough at high speed, which actually bucked us off the pedals. In general we found the bike to be comfortably plush with no surprises, so the abrupt kicking sensation certainly caught us off guard. This happened in the middle high-speed compression setting.


The Demo seems to trade outright pedaling efficiency in the traditional sense for improved suspension action when pedaling through the rough - if you’re able to sneak in those pedal strokes, that is. Out of the gate it’s not the snappiest rig, but it gets along decently well. This tradeoff was likely necessary to achieve the extremely low levels of pedal-kickback.

So what of the sizing? As you might guess, the Medium made for a more playful ride that was very easy to move around. Switching to the Long, the wide open fast trails called our name. At 5'10" tall we did find weighting the 20mm longer front end a bit harder, requiring a conscious effort to get over the bars in turns or risk the front end pushing slightly. Both were very easy to throw sideways in the air and place on the ground with precision, due in part to the low weight of the complete build.


Build Kit

It’s no secret that how a bike rides is the sum of it parts, and Specialized has done a nice job spec’ing the S-Works Demo with a careful mix of SRAM, RockShox, Öhlins, Roval, Thomson, and in-house components.

Specialized swears by the performance of a steel spring for downhill applications, explaining the decision to spec the RockShox BoXXer Team over the World Cup model. The Charger Damper equipped fork complemented the rear end very well with smooth, supple, controlled performance. Only on the steepest trails did we find that it was a bit easy to get down in the travel on successive hits.


The 2.5-inch Specialized Butcher DH tire up front provided the reliable cornering and braking performance we’ve come to admire it for. We have to wonder about Specialized’s decision to include the 2.3-inch Slaughter DH tire in the rear, however. While the semi-slick style tread pattern may lend itself well to trail bikes and improve rolling speed, we feel like proper knobs are called for in all but race scenarios, especially for those that ride where it rains. Luckily the thing bites in well when you lean it over. We also cut a sidewall somewhere in the rocks.

In the wheel department you’re looking at Roval’s 650b aluminum rims paired with custom DT Swiss hubs and straight-gauge DT Swiss spokes. This combo offered no issues, though we did put a decently sizable dent in the rear rim. Whistler is notoriously hard on wheels, so we suppose that was to be expected.

From the grips to bend of the bars and feel of the saddle, Specialized’s cockpit choices were dialed. Everything felt in its proper place.

Finally, SRAM’s dead silent and purpose built X01 DH drivetrain really adds to the S-Works Demo experience. Quiet bikes with smooth shifting flat out feel better, and this system achieves both very well. It’s also incredibly easy to find the perfect gear at a moment’s notice.


What's The Bottom Line?

At the end of the day, the big question is likely, "is it a better Demo?" Provided those big ol' bearings and funky square axle interface hold up in the long term, yes, we think so. While there's a distinct similarity between the two machines when it comes to suspension performance, the full carbon frame is lighter and calmer through the rough, which encourages you to open it up just a bit more. The updated geometry makes it a bit more of a capable all-arounder, too.

As we said early on, the 2015 S-Works Demo is quiet, controlled, and composed at almost all times, which makes it easier to ride faster. The combination of perfectly balanced suspension and a dialed list of reliable components make for a ride that puts your nerves to rest and lets you focus further down the trail. Point, shoot, and let it rip. That's a winner in our book.

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About The Reviewer

Brandon Turman likes to pop off the little bonus lines on the sides of the trail, get aggressive when he's in tune with a bike, and to really mash on the pedals and open it up when pointed downhill. His perfect trail has a good mix of flow, tech, and balls-to-the-wall speed. He loves little transfers, rollers, and the occasional gap that gives him that momentary stomach in your throat kind of feeling. Toss in some rocky bits with the option to double over them or risk pinch flatting and you've got a fun trail in his book. In 14 years of riding he worked his way through the Collegiate downhill ranks to the Pro level. After finishing up his mechanical engineering degree, his riding focus turned to dirt sculpting and jumping with the occasional slopestyle contest thrown in for fun. Nowadays he's Vital MTB's resident product guy, putting in saddle time on nearly every new platform and innovation the bike industry has to offer.


Product Specialized Demo 8 S-Works Carbon 650b
Model Year 2015
Riding Type Freeride / Bike Park, Downhill
Rider Unisex
Sizes and Geometry
S, M, L, XL View Geometry
Size S M L XL
Top Tube Length 577mm 588mm 613mm 633mm
Head Tube Angle 63.5° 63.5° 63.5° 63.5°
Head Tube Length 105mm 105mm 115mm 115mm
Seat Tube Angle 76° 76° 76° 76°
Seat Tube Length 394mm 394mm 419mm 419mm
Bottom Bracket Height 343mm 343mm 343mm 343mm
Chainstay Length 430mm 430mm 430mm 430mm
Wheelbase 1184mm 1209mm 1233mm 1253mm
Standover 702mm 707mm 712mm 718mm
Reach 395mm 420mm 440mm 460mm
Stack 614mm 614mm 623mm 623mm
Wheel Size 27.5" (650b)
Frame Material Carbon Fiber
Frame Material Details FACT 11m Carbon Front Triangle, Full Carbon Link and Rear End, FACT IS Construction, Full Internal Cable Routing
Rear Travel 200mm
Rear Shock Ohlins TTX22M, Coil Over with Piggy Back, Spherical Bearing Mount, High/Low Speed Compression, Rebound Adjust, 9.5x3.0"
Fork RockShox Boxxer Team 650b, Coil Spring, Tapered Alloy Steerer, High/Low Speed Compression and Rebound Adjust, 20mm Thru-Axle
Fork Travel 200mm
Head Tube Diameter Straight
Headset 1-1/2" Semi-Integrated for 1-1/8" Steerer, Cartridge Bearings
Handlebar S-Works DH, Carbon, 8° Backsweep, 6° Upsweep, 31.8mm, 780mm
Stem Specialized P.Series MTB, Direct Mount, Forged Alloy, 4-Bolt, 45mm
Grips Specialized Sip Grip, Light Lock-On, Half-Waffle
Brakes SRAM Guide RS DH, Metallic Pads, Code Caliper, 200mm Rotors
Brake Levers SRAM Guide RS DH, Alloy Lever, with Cartridge Bearing, Reach Adjust
Drivetrain 1x
Shifters SRAM X01 DH, 7-Speed
Front Derailleur N/A
Rear Derailleur SRAM X01 DH Type 2, 7-Speed, Short Cage
ISCG Tabs Yes
Chainguide Gamut
Cranks SRAM X0 DH, BB30, Carbon Arms, Triple Base
Chainrings with Gamut Bashguard
Bottom Bracket SRAM, BB30 to BSA 83mm Adapter
Pedals Specialized Boomslang, 10mm Low-Profile, Sealed Bearing
Chain SRAM PC 1130, 11-Speed, with PowerLink, Nickel Finish
Cassette SRAM X01 DH, 7-Speed, 10-24 Tooth
Rims Roval 650b, Alloy, 24mm Inner Width, 32 Hole
Hubs Specialized Hi Lo Disc, Sealed Cartridge Bearings, Thru-Axle Front // Custom DT Swiss, Star Ratchet, XX1 Driver Body, Thru-Axle Rear
Spokes DT Competition, Stainless, 2.0mm
Tires Specialized Butcher DH, 60TPI, Wire Bead, Dual Compound, 27.5"x2.5" Front // Specialized Slaughter DH, 60TPI, Wire Bead, Dual Compound, 27.5"x2.3" Rear
Saddle Body Geometry Phenom Expert, Hollow Ti Rails, 143mm
Seatpost Thomson Alloy Straight, 12° Clamp, 300mm
Seatpost Diameter
Seatpost Clamp Specialized 7050 Alloy, Single Bolt, 36.9mm
Rear Dropout / Hub Dimensions 135mm x 12mm
Max. Tire Size
Bottle Cage Mounts N/A
Colors Satin/Gloss Red/Carbon
Warranty Lifetime Frame, 5 Years Suspension Attachment Points and Related Equipment (Pivot Points, Bushings, Chainstays, Seat Stays, Shock Links, Fasteners)
Weight N/A
Price $9,000
More Info Specialized Website

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