EXCLUSIVE: Specialized Demo 8 Carbon - First Look

Specifications Release Date 2013 Price Travel 200mm Rear Shock Custom RockShox Vivid, Ti spring Fork Custom RockShox Boxxer World Cup, Black Gold stanchions Headset 1-1/2" integrated for 1-1/8" steerer Cassette Shimano HG-70 Capreo, 9-speed, Micro 9-26 Crankarms SRAM X0 DH, carbon arms, micro-single 32T ring Chainguide E.13 chainguide Bottom Bracket SRAM PF30 DH, 83mm shell Pedals Specialized Bennies Chain KMC X9 SL, nickel plate Rear Derailleur SRAM X0, 9-speed, short cage Shifter Pods SRAM X0, 9-speed Handlebar Renthal Fat Bar, 780mm wide, 7-degree backsweep, 31.8mm Stem Renthal Integra, direct mount, 45mm, integrated 6-bolt Grips Specialized Sip Grip Brakes Custom Avid Code X0 World Cup, hydraulic disc, Code caliper, organic pad, stainless hardware, 200mm rotors Hubs DT Swiss 240S, 20mm thru-axle, Custom DT Swiss, Capero compatible, Star Ratchet, 135mm, Spokes DT Swiss Competition, stainless, 2.0/1.8/2.0mm front, 2.0 rear Rim Custom DT Swiss FR 600, 32h Tires Specialized Butcher DH, 60 TPI, wire bead, soft dual-compound, 26x2.3" Seat Custom SDG I-Fly, World Champion stripes Seatpost SDG Storm I-Fly, 300mm Compare to other DH/Freeride Bikes

Specifications Release Date 2013 Price Travel 200mm Rear Shock Custom FOX DHX RC4 Fork RockShox Boxxer RC Headset 1-1/2" integrated for 1-1/8" steerer Cassette Shimano Tiagra, 10-speed, 11-25 Crankarms Custom SRAM Descendant PF30 Chainguide Gamut P-30 chain guide Bottom Bracket SRAM PF30 DH, 83mm shell Pedals Specialized Bennies Chain KMC X10 Rear Derailleur SRAM X9 Type 2, 10-speed, short cage Shifter Pods SRAM X7, 10-speed Handlebar Specialized Demo low-rise bar, 750mm Stem Specialized Direct Mount Grips Specialized Sip Grip Brakes Custom Avid Elixir 5 R Hubs Specialized Hi Lo, Spokes DT Swiss Rim Roval DH 26, alloy disc, 30mm wide Tires Specialized Butcher DH, 60 TPI, wire bead, soft dual-compound, 26x2.3" Seat Specialized DH, 8mm hollow Cr-Mo rails Seatpost Specialized 6061 alloy, two bolt micro adjust, Compare to other DH/Freeride Bikes

The Carbon Demo 8 I may not garner as much attention as the S-Works Demo 8 Team Replica, but its less expensive entry price will make the black and white bike a more realistic option for most riders. It uses the exact same geometry, including the three positon shock eyelet cam, but is built around a slightly heavier FACT 10m carbon frame. How much heavier is it? Specialized claims that the Carbon Demo 8 I frame weighs just 50 grams more. The bike's main link is aluminum - the Team Replica uses a magnesium link - and the rear end spacing is a more common 150mm in place of the S-Works' 135mm. You also won't find the trick six speed cassette and tiny chain ring. What the Carbon Demo 8 I does offer, though, is a very similar build kit to the standard alloy version, expect that it is all assembled around a carbon frame that is nearly a full pound lighter than the aluminum version. Pricing is still unavailable, but we're looking forward to seeing what the Carbon Demo 8 I comes in at - it could end up being quite the steal for a carbon downhill bike. Expect an August release date.

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Demo Evolution

The Demo platform has been in use since 2004, the year that Specialized first released the Demo 9. That early version, designed during a time when weight was of less concern, was suited more toward going large than going fast between the tape. What it did do, though, was prove that the bike's novelly arranged, four-bar FSR suspension system was very adapt at handling the terrain. The design lost weight over the years, trimming down as the times demanded, but it wasn't until Specialized signed Sam Hill that the entire focus of the Demo platform changed. The design now shifted from an all-around ethos (as 'all-around' as a downhill bike could be anyways ) to one that was purely focused on racing. Hill wanted the bike lower, closer to the ground than nearly anything else out there, as well as slacker to handle the speeds of racing at the top level. Specialized accommodated Hill's wishes and the next generation Demo was raced to wins by the entire team - National wins, World Cup overalls, and World Championships were all taken aboard the new bike. The next logical step, of course, is carbon fiber.

Aluminum Head Tube Sleeve

There are many carbon frames out there that see their headsets pressed in to mate directly against the carbon, a layout that has proven to be trouble free over time. Regardless, Specialized wanted to absolutely eliminate any chance of an issue arising on the Demo. The choice was made to utilize an aluminum sleeve (above, right ) throughout the full length of the head tube, providing a metal contact surface for the headset cup to interface with. This route wasn't necessarily taken because the project's engineers were concerned about the carbon tube's ability to withstand riding abuse, but more to facilitate the consumers who might be removing and installing angle adjusting headsets more often than they would on a bike designed for a different purpose. The sleeve may add a few grams, but it is in line with Specialized's goal of creating a frame that exceeded their strength and durability goals. A threaded aluminum insert (above, left ) is also home to the main link's forward attachment point on the front triangle



Aluminum Rear End

Specialized chose to continue using an aluminum rear end for the new Demo, which may come as a surprise to some given that they do offer other full suspension models with carbon stays. ''In the end we determined that the biggest benefits could be had in the front triangle,'' Chamberlain told us, "Carbon chain stays and carbon seat stays didn't provide as big a benefit as we wanted, so for the time being we decided to focus on just the front triangle.'' Having said that, there was certainly a knowing smile on Chamberlain's face as finished that sentence. We're willing to bet that they most certainly tested a carbon rear end, even if they wouldn't admit to it, and that it will make an appearance at some point in the future. The weight loss in a carbon rear end is likely to be relatively small, but the fact that it would come in lighter at all basically ensures that they will be pursuing the concept in the long run.

Unidirectional Carbon and Mandrel Technology

Sometimes it is actually what's missing from a design can be a most telling, and what's absent from the Demo 8 Carbon is the weave finish that many carbon neophytes associate with the ordained material. That typical carbon fiber weave appearance is a product of the alignment of the cloth fibers, and although that particular layup has benefits when it comes to certain applications, it often isn't the best choice in the bicycle world. Unidirectional carbon is just as its name would have you believe: all of the material's filaments are aligned in the same direction. This is especially important to note when you consider that carbon is at its strongest when loaded along its axis, meaning that laying up the UD carbon in a particular way will allow its strength to be fully taken advantage of. The end result should not only be a stronger finished product, but one that will also require less material to meet the design and strength goals. This is especially true when dealing with the tight curves and challenging shapes found on the Demo 8 Carbon frame, a job that is much better suited to the more pliable nature of unidirectional carbon. While this is accurate when talking about most mountain bike frames and components, it isn't uncommon for a manufacturer to apply a carbon weave to the outside of the product simply to make it abundantly clear to anyone and everyone that their goods are made with carbon fiber. This, of course, adds useless weight to the final product, weight that serves no purpose other than to yell ''look at me, I'm carbon.'' Inspect the bare sections of carbon on both the S-Works Demo 8 Team Replica and Carbon Demo 8 I bikes and you'll see none of this, with Specialized merely giving the frame a spay of protective clear coat.

It's generally agreed upon that a well made carbon frame can surpass an alloy frame of similar design and intention when talking strength, rigidity, and weight. However, alloy frame manufacturing, especially when done robotically as is often the case, can be performed on a more consistent level. A carbon frame, on the other hand, requires its separate carbon cloth sheets to be laid down in exactly the correct orientation in order for the frame to be as strong as the designer intended. This is a point that all manufacturers focus on, and Specialized has put a large priority on this with the Demo. Changes to the layup and mold components ensure that the carbon sheets don't shift during frame construction, but a new mandrel technique also come into play. Many carbon frames are made using a latex bladder that the carbon sheets are laid over, followed by pressure and heat being applied from all sides by a two-piece steel mold. The issue arrises when using the latex bladder method to construct complicated carbon shapes, a task that is possible but also one that often requires more carbon and results in the bladder being trapped within the frame. Instead, complicated sections of the Demo front triangle, which is built by joining separate front and rear sections, are formed using a very special type of foam in place of a bladder. The foam used has a specific melting point that allows it to be removed from the frame when heated to a certain temperature. The result is not only a lighter frame due to there not being a latex bladder jammed inside of it, but also more even compaction of the unidirectional carbon cloth that equals a void-free, and therefore stronger, frame.

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In-house Testing

Specialized isn't shy about their carbon frames being manufactured in Asia, especially in this day and age when many top quality carbon frames and components hail from overseas. One point that they are quick to point out, though, is that although their frames are fabricated in Asia, Specialized actually puts each design through their own demanding tests in their in-house test lab in Morgan Hill, California. This is a step that some other companies use a third party for, or even leave it up to the Asian manufacturer themselves (producing not so objective results, no doubt ). This test lab played a large role throughout the carbon Demo's development, allowing the engineers on the project to test the stiffness and strength of each version of the frame. In all, seven different carbon layup revisions were assessed, with the final version being ''...by far the strongest bike we've ever made'', according to Chamberlain. ''So we wanted to make sure that it exceeded the strength of the alloy bike,'' he continues, "as well as exceeded all of our internal test standards''. This is on top of the fifteen to twenty different virtual renditions that were run through computer simulations long before a single piece of carbon was laid down. All told, the Demo 8 Carbon frame has two years of development and testing behind it, much of which took place in the test lab pictured above.

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