First Look: 2015 Specialized S-Works Demo 8 Carbon 650b

Radical asymmetric frame, new FSR link and 27.5 wheels at heart of new design

27.5 DH

2015 Specialized Demo Gwinn MSA

Aaron Gwin debuted the 2015 S-Works Demo 8 at the Mont Sainte Anne, Canada world cup where he finished fifth. Last weekend he rode the bike to a second place finish at the Windham, New York stop of the series. Photo courtesy of Specialized

When Specialized’s downhill duo of Aaron Gwin and Troy Brosnan showed up with new bikes at the Mont Sainte Anne, Canada stop of the downhill world cup a couple weeks ago, exactly zero people were surprised they rolled on 27.5-inch wheels. The new hoop size was a given, but a few significant design changes weren’t—in particular a radical asymmetric seat tube design and some significant tweaks to their vaunted FSR suspension configuration.

2015 Specialized Demo 650b

Now a few more weeks down the road and some world cup podium spots later, Specialized is officially filling in the blanks on the production 2015 Demo 8 bikes and framesets, which, unlike the team bikes, come with a new version of the Öhlins TTX that shipped with the bike last year.

Don’t call me Lefty: Demo’s seat tube is one-sided

Perhaps the most dramatic change to the Demo is the omission of its traditional pierced seat tube design in favor of an asymmetrical configuration with only a right-side frame member extending to the bottom bracket. The shock is also mounted slightly off-center to the left, helping to center the load. Specialized says while this did cost them a smidge of stiffness on the front end, it allowed them to simplify access to the shock and lower the bike’s center of gravity—something Gwin noted right away.

“The thing I noticed the most was how quick you can change directions and how hard you can slam it into turns,” said Gwin, the 2011 and 2012 world cup champion who struggled to get on terms with his Specialized in 2013. “It’s a really lively bike, but when you get it in the bumps it eats them up really good.”

Even before the new bike Gwin was having a good year, hovering in the top-3 for the overall. On the new Demo he’s finished second and fifth in two races—Windham and Mont Sainte Anne, respectively.

Single-sided and offset Demo offset

Specialized says the unique asymmetric seat tube on the new Demo Carbon makes the bike handle better and the shock easier to access.

Lighter, lower FSR layout

Complimenting the lively front end is an all-new FSR rear linkage, designed to be lighter, lower and more responsive. With a massive concentric main pivot that rotates around the bottom bracket, Specialized says it’s also stiffer, which nets out to an overall improvement from the old Demo despite what the new front end gives up. The Demo sports 200mm of rear travel and remains active under braking due to its floating seat stay. It also looks much cleaner than the previous Demo’s double linkage.

Demo compare-o

Side-by-side, the difference is dramatic.The 2015 Demo FSR (right) has only one linkage, while it’s predecessor had two, which looks kludgy and heavy by comparison.

Swedish shock is simple, adjustable

While Gwin runs FOX suspension and Brosnan is a RockShox man, the production Demos come stock with a new version of the Öhlins TTX twin tube rear shock they spec’d on some builds of the bike last year. Specialized claims the shock was made to work specifically with the new FSR build and that it has reduced mid-speed compression for control on initial hits and increased high-speed compression for better management of at-the-limit hits. They also describe its adjustability as wide-ranging yet simple. Like on last year’s bike, the shock uses a ball joint on the upper eyelet allowing it to float and reducing side loads.

Ohlins TTX shock

DH S3 geometry emphasizes riding style and length

While the standover height of the bikes does increase slightly from size-to-size, Specialized focuses fit more in terms of the optimal top tube length for your riding style rather than rider height. Even the size naming convention—short, medium, long, x-long—speaks to the emphasis.

“The frame sizes are dependent on the rider’s style, not how tall they are,” says the company’s press materials. “With a low seat tube and standover height on all sizes, the rider should first consider if they prefer a shorter, snappier-handling top tube and wheelbase or a longer, more stable top tube and wheelbase.”

2015 Demo Carbon Geometry

“Low” is a recurring theme for the 2015 Demo, and at 13.5-inches the bike’s bottom bracket was hung to carve. Combined with a 63.5-degree head tube angle and 16.9-inch chainstays, Specialized was clearly looking to keep things as low and tight as possible. The effective seat tube angle falls in the DH bike sweet spot at 76-degrees.

First look video of Aaron Gwin’s new World Cup DH bike. Go behind the scenes to secret R&D sessions that created the 2015 Specialized S-Works Demo DH bike.


Available in January, pricing not yet set

The new Demo comes as a complete bike in Specialized’s top-of-the-line S-Works kitting as well as a step=down version, and is also available as a frameset only. The bike should hit dealers in January and pricing has not yet been set.

For more information visit

About the author: Don Palermini

Chicago-born Don Palermini became a cycling-based life-form in the sixth grade after completing a family road bike tour of his home state. Three years later he bought his first mountain bike to help mitigate the city's pothole-strewn streets, and began exploring the region's unpaved roads and trails. Those rides sparked a much larger journey which includes all manner of bike racing, commuting, on- and off-road bike advocacy, and a 20-plus-year marketing career in the cycling industry that landed him at his current gig with Santa Cruz bicycles. Now residing in the San Francisco Bay Area, his four favorite words in the English language are "breakfast served all day," together in that order.

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  • guillermo says:

    gracias mtbr que nos da a conocer como avanza la tecnología y así la Pasión que crece por el ciclismo, las montañas, competencias, exhibiciones, etc. felicidades.

  • Preston says:

    This new bike looks so hot.
    Only two things bother me – why 7 speed ? I understand for absolutely pure racing that is probably fine but even the most core racer must want to take it to the park once in awhile ? I find I still use all 9-10 speeds and I need a gear to climb up that little hill to Schleyer/Joyride ha ha.

    also I always thought the complex Demo linkage was “to isolate shock actuation from wheel movement” that’s what S told us all these years. Are you telling me that was just marketing ??!!! Oh well I guess technology always moves on and new designs are conceived. I knew it was probably a mistake to buy a new Demo this year but maybe that’s why the bike shop gave me such good deal on it.

    • Leo says:

      This bike is purely DH, putting a 10 speed cassette on this bike would just be a mess, add weight and reduce chain tension unless the derailleur had mega beefy springs. If you’re looking for a bike that can also climb hills consider an AM bike other than that you’ve got a point.

  • aaron says:

    Is this new demo still going to be a free ride beast. Or have they gone stickly down hill? Id like to pick one up. But not sure after what i have read it can take the monster hits like the previous Demo’s. Does anyone know?

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