The Fuji D-6 Time Trial / Triathlon bike – the first project of the Delta-Six design lab – isn’t just a piece of carbon eye candy, it performs (and out-performs) like no other windcheater on the road today. We focused on what matters: aerodynamics, stiffness, weight and fit, and then we took it to the next level. We added unique innovations that give the D-6 advantages never before seen in a time trial bike. The D-6 is available in two models – the D-6 Professional and D-6. It is also available as a frameset – the Matt Reed Signature D-6 – that features custom-designed graphics approved by the big guy himself (page 30). All three models use the same frameset: a semi-monocoque mold design using high modulus carbon fiber (Fuji’s C7+) with custom weave strands, aero-shaped tubes, internal cable routing and an extended seat tube. The fork is Fuji’s FC-440 carbon monocoque with integrated 1 1/8” carbon steerer and custom designed internal cable routing. Sizes: XS, S, M, M/L, L and XL.
Aerodynamics.
We began by exploring aerodynamic profiles put out by the
National Advisory Committee for Aeronautics (NACA) and applied that knowledge using CFD fluid modeling and wind tunnel experimentation. The D-6 excelled, putting it squarely on the map as a top aerodynamic performer. One of the most intriguing and, surprisingly, unique findings was that the drag coefficient actually decreased when the wheels were spinning as compared to stationary.
Stiffness.
A frequent comment from our professional athletes was the need to maximize power transfer from rider to bike, without wasting precious energy fighting and recovering from every bump in the road. The D-6’s semi-monocoque carbon design, meticulous carbon layup procedure, and choice of high-modulus fibers give the frame stiffness without sacrificing torsional and vertical compliance. The result? Comfortable performance.
Fit.
Optimal bike fit is, well, personal. Different athletes have different requirements. Triathletes, for example, need geometry that allows for a smooth transition into the run, and TT specialists may ride a position that feels like their regular road bikes. We tackled this issue by designing a bike that accommodates multiple fit needs. Six frame sizes cover riders from 4’9” (1.4 meters) to 6’5” (1.9 meters ) and the independent adjust (iA) saddle clamp provides a range of seat tube angles from 74 to 80 degrees. Add to this the most up-to-date stack and reach requirements, and you’ve got the perfect platform to find your optimal mix of efficiency and aerodynamics.
Weight.
Bike weight is important. And while sometimes confusing or misleading, it should be straight forward, so here’s the nitty gritty as it applies to the D-6. A 56cm (size M/L) D-6 Professional frame weighs in at 1390 grams and the fork, 398 grams – this includes all bonded parts, paint and decals. Compare that to the raw frame weighing in at 1065 grams and the raw fork at 392 grams. The complete bike, as spec’d, weighs 17.7 lbs (7.9 kg). So, when you’re comparing weight and stiffness – and we encourage you to – be sure you are comparing apples to apples.
UNIQUE REAR BRAKE HOUSING
While some companies are placing the rear brake in the bottom bracket area to remove it from the wind, we opted for an innovative approach to the traditional seat stay position: a unique brake cavity integrated into the carbon mold. Not only does this accomplish the same aerodynamic purpose, it allows the brake to remain easily accessible. It also increases overall stiffness. By beefing up, and therefore stabilizing, the top tube/seat mast/stay junction, the relationship between that area and the BB area is reinforced, resulting in unparallel direct drive ride quality.
INTERNAL FRONT BRAKE CABLE ROUTING
While we are not the first engineering team to determine that placing the brake behind the fork crown would minimize frontal area turbulence, we were the first to remedy the excess turbulence caused by the brake cable housing in the front of the head tube. We created a unique internally routed cable that runs through the fork and out to the brake. To do this, we had to develop a new compression assembly that would allow the cable to run through the fork. This custom designed construction allows adjustments to be made to the headset using a standard tool.
INDEPENDENT ADJUST (Ia) SADDLE CLAMP
Because we incorporated a seat mast into the D-6 design, we opted to go with an external seat post rather than a traditional internal one. This design increases strength and stiffness at the seat post/top tube/down tube junction. We also added a unique saddle clamp that allows independent adjustment (iA) of fore/aft, tilt and rail ompression. Other systems only allow you to make adjustments by loosening the clamps, so consequently you end up losing your fore/aft or tilt position. Fuji’s new iA system allows you to easily replace your saddle or make independent fore/aft or tilt adjustments while maintaining your preferred riding position.