You've seen the radical asymmetric design in the wild, now get the nitty gritty details on Specialized's all-new Demo.

First spotted at Crankworx Whistler last year in prototype form, today Specialized released full details for the all-new 2015 S-Works Demo Carbon. Aaron Gwin and Troy Brosnan raced the bike at the Mont Sainte Anne and Windham World Cup races, and it will be available to the public in January 2015.

2015 S-Works Demo Carbon 650b Highlights

  • 650b wheels
  • 200mm travel
  • Full FACT 11M carbon frame
  • Custom tuned Öhlins TTX22M rear shock
  • Asymmetric seat tube design
  • Internal cable and brake routing with optional external brake routing
  • Internal cable guides for easier routing
  • 1.5-inch headtube
  • 83mm BB30 bottom bracket
  • Molded chainstay, seat stay, and downtube guards
  • Unique 12x135mm L7 square rear axle
  • Frame weight: 7.6 pounds (without shock or protectors, size Medium)

Testing With The Pros

Just days after the USA Downhill National Championship, we met up with the Specialized World Cup team for a secret test session on the all-new Demo:

Asymmetric Design

The new asymmetrical seat tube is a weight savings measure meant to lower the center of gravity. The design also allows for easy access to the Öhlins TTX22M rear shock.

Specialized found that the seat tube didn't have to be overbuilt to support the seatpost and rider, inspiring them to move to the asymmetric design. By shifting the shock to the left slightly, they were able to make room for the shock while making a one-sided seat tube with more surface area than two smaller tubes.

Specialized designers experimented with several asymmetric designs before arriving at the final version. It's a work of art in person.

FSR Suspension Updates

Over the past several years, Specialized evaluated dozens of new suspension designs with lots of emphasis on momentum and braking response. Their tests found that the FSR system continuously came out near the top with few drawbacks. Content with the performance of FSR, they then attempted to lower the center of gravity further by lowering all pivots by 3-inches.

The updated FSR suspension design utilizes a concentric main pivot at the bottom bracket - something not often seen anymore in the downhill world. Packaging the design in a lightweight and compact way was a challenge. Ultimately custom 50mm bearings with small cross sections were used to keep things light. The concentric system is essentially one big axle that threads in.

Kinematically the new and old designs are very similar. The new design does have slightly more anti-squat for improved flat-out pedaling performance, as well as slightly more progression to absorb big hits. All pivots have larger bearings with custom Teflon lip seals. The 2015 Demo sees just1/3 of the friction in the linkage compared to the previous frame.

Specialized and Öhlins will continue to pair their creations together in 2015. The twin-tube rear shock has been tuned specifically for the frame, eliminatingunnecessary clicks or adjustments. The shock rides on updated ball bearings for smoother action, and doesn’t require a unique length or mounting hardware. The shock has a shorter rebound knob for easier spring removal, reduced mid-speed compression for more control on initial hits, and increased high-speed compression for increased control when at the limit.

Thanks to the use of carbon, bigger pivots, bigger bearings, and a new "L7" square axle design, the rear end is actually torsionally stiffer than the previous design. The floating seatstay keeps the pedaling and braking forces separate from suspension activity, while the standard size 12x135mm axle has been engineered to stiffen the rear end. Specialized uses a 135mm rear end because it's less weight while providing more heel and frame clearance in tight situations.

DH S3 Geometry

Four sizes designated Short, Medium, Long, and X-Long will be offered with similar seat tube heights. 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.

Prefer a shorter, snappier-handling top tube and wheelbase? Or perhaps a longer, more stable top tube and wheelbase? Now you can choose without concern about seat tube heights. For reference:

  • Troy Brosnan (5’7") - rides a medium
  • Aaron Gwin (5’10") - rides a long as he likes the longer, more stable wheelbase
  • Mitch Ropelato (5’8") - rides a medium as he likes a tighter, whippy bike
  • Brad Benedict (6’1") - rides a long in the park and an X-Long for racing

The low geometry is headlined with a slack 63.5-degree headtube angle, low 343mm BB height, and short 430mm chainstays. Compared to the 2014 Demo, this new version has slightly longer chainstays, a longer wheelbase, and longer reach across the size range.

Demo Carbon Models

The Demo carbon will be available in S-Works and Carbon 1 models:

The S-Works FACT 11m frame is a full front and rear carbon frame, complete with carbon link.

The Demo 1 Carbon FACT 10m frame has the same front triangle and carbon seatstay, with an aluminum alloy chainstay and link. Both models use a custom 7-speed drivetrain, coil-sprung RockShox BoXXer fork, Öhlins TTX22M rear shock, Roval 650b rims, and Specialized tires. Frame only options are also available.

Pricing has yet to be finalized, but expect the complete S-Works model to be in the $10,000 range and Demo 1 Carbon model a bit below that. Availability for both versions is expected in January 2015.

Visit www.specialized.com for more details, and stay tuned for our ride impressions right here on Vital MTB!

Bonus Gallery: 19 detail photos of the 2015 Specialized Demo Carbon 650b

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5 comments
  • t.martin

    8/13/2014 9:49 PM

    Can't wrap my head around why they chose a 12x135mm rear end.. Why not stick with the new-and-improved industry standard of 12x142 if they are going to tighten things up? Wouldn't there be a loss of lateral wheel stiffness? Seems like they went backwards there..

  • esstinkay

    8/14/2014 11:57 AM

    12x142 is stiffer than 10x135 because of the larger diameter axle, and bolt through design vs quick release. 12x135 would be stiffer than 12x142 since the axle length is shorter and has less leverage. And the smaller size will increase heel clearance

  • dom.wrapson

    8/14/2014 3:06 PM

    But the axle length and swing-arm width is exactly the same..?! The only difference is a wider flange on the hub (3.5mm each side accounting for the 7mm difference in 'standards') and grooves on the drop-out to make it easier to locate and seat your wheel when replacing it in the frame. "Floating" axle/hub combos are a complete pain-in-the-ass to properly locate; 142 is widely adopted and loved for a reason.

    http://forum.cyclingnews.com/showthread.php?t=16729

  • onenerdykid*

    8/13/2014 3:40 AM

    Saying that the updated version of the Ohlins shocks does not require unique mounting hardware, does that mean the spherical bearing at the front mount is gone? This would be a good thing in my experience...

  • SpamHill

    8/13/2014 7:44 AM

    I agree, on a muddy day that front bearing squeals like a stuck rat. I think they mean that there's no yoke at the back though.

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