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THE ATHLETE’S MIND NEVER RESTS —Neither do ours.

The Andean unlocked several aerodynamic puzzles, which has given us the experience to push even farther.

With the IO we fused those innovations along with several new ground-breaking technologies into a wicked-fast, lightweight, and slippery road bike.

VISION & DESIGNWhen our engineering team began to design the IO, we saw the need for a bike that better combines the benefits of a road bike and a triathlon bike. We wanted to provide a performance edge to athletes competing in triathlons and self-supported ultra-endurance events where an aero road bike rather than a pure triathlon bike is the tool of choice.

When Diamondback engineers develop a frame, they first consider the needs of the rider. While each of our frames requires a minimum level of stiffness, strength, weight, and aerodynamic efficiency, the intended use of the bicycle determines which of those characteristics we place our focus on.

Triathlon and time trial bikes, such as the Andean and Serios, are designed around aerodynamic efficiency. The rider spends the bulk of their time in the wind, on their own, and needs to maximize the aerodynamic savings throughout the ride. While weight is a consideration, it falls lower on the priority list.

On the other hand, road riding tends to involve more climbing than triathlons and time trials. Therefore, weight savings takes a higher priority, with the effort to shave grams often coming at the expense of aerodynamic efficiency. Instead of tubes being designed as complete airfoils, they are often truncated to save weight.

To achieve our design goal, we needed to focus on both weight savings and aerodynamic characteristics. Having previously developed the Andean, the Serios, and the refresh of the Podium with our partners, Kevin Quan Studios, we already had a solid foundation on which to begin.

We chose to take the same integrated design approach we used with the Andean. Our integrated approach looks at the bicycle as a complete system because we believe this provides a better end result than if we were to simply look at the frame in a vacuum, as some manufacturers do. Our engineering team spent hours poring over the Computational Fluid Dynamics (CFD) modeling not only of the frame but of all other elements that affect aerodynamic drag — the rider, components, how nutrition and hydration are stored on the bike, and so on.

We also followed a similar testing protocol to what was used for the Serios, Andean, and Podium refresh. Once our engineering team was satisfied with the CFD modeling, it was time to move into the wind tunnel. Our first step was to use a scaled model of the IO in the low-speed wind tunnel, which allows for more meticulous testing. From there, we moved the IO into a large-format wind tunnel to prove the design in full scale.

As a result of the research and testing our engineering team did, we realized that we needed to focus on two areas of the frame: the area we call the SpeedCore, encompassing anything below the top tube, and the cockpit, which begins with the handlebars and spans the top tube to the seat.

What follows is an overview of what our engineers were able to accomplish in those key areas to maximize aerodynamic benefits while providing additional performance benefits to the rider.

THE ADVANTAGEThe SpeedCore features three design elements that, functioning as a system, give the IO its competitive advantage. At its core lies the Diamondback Wake Control System, which represents an industry first in bicycle frame design. Ultralow Seat Stays and Aero Bottom Bracket Storage provide additional aerodynamic efficiency as well as other benefits key to rider comfort and performance.

DIAMONDBACK WAKE CONTROL SYSTEM

A bicycle frame is made up of six main tube areas — head tube, top tube, down tube, seat tube, chainstays, and seat stays. When developing the IO, our engineering team reviewed every tube area to determine where improvements to aerodynamic efficiency, ride performance, and rider comfort could be made.

Of all the factors within our control, tube shapes have the biggest impact on aerodynamic performance. A perfectly shaped airfoil helps the air stay attached across the shape, minimizing any turbulent airflow. When engineering a road bike frame, manufacturers are often required to truncate the tube shape to reduce weight, improve structural strength, or allow for component clearance. The shortening of the airfoil, while providing other benefits, negatively impacts the aerodynamic performance, creating a higher amount of drag, or wake, coming off the bike.

In the past, many bicycle manufacturers have attempted to control the wake by developing custom shapes and dimpling leading edges. Our engineering team researched these existing options when designing the IO but found they fell short of providing the aerodynamic efficiency we were looking for on this frame.

Facing the challenge of making a truncated airfoil perform more like a complete airfoil shape, the Diamondback engineering team enlisted the help of Dr. Phillipe Lavoie and his team at the University of Toronto Institute for Aerospace Studies. Dr. Lavoie and his colleagues have long studied the effects of airflow across surfaces for many different applications and at

many different speeds. His team had previously provided valuable input during the research, design, and testing phase of the Andean.

Dr. Lavoie’s team shared research they had done on helicopter blades and wind turbines. Their work revealed that by strategically altering the way the airflow leaves a truncated airfoil, we could reduce the amount of wake, improving the aerodynamic performance. Armed with this knowledge, our team worked to see if it could be applied to a bicycle.

After additional research, our engineering team moved on to designing and testing several variations in both CFD modeling and the wind tunnel. Our initial attempts revealed the same principle could be applied, but specific placement would be vitally important. After hundreds of hours in research and design, and with input from Dr. Lavoie and his team, our engineering team developed the Diamondback Wake Control System.

Our Wake Control System is formed by engineering strategically shaped depressions called vortex generators into the trailing edge of the truncated airfoils. These depressions set up mini areas of counter-rotating turbulent flow. When precisely placed in a specific pattern, the counter-flow areas interfere with natural airflow across the frame and significantly reduce the wake that leaves the bike. The IO’s vortex generators better control the wake and significantly improve the aerodynamic performance compared to other aero road bike designs.

ULTRALOW SEAT STAYS

In addition to researching tube shape, our engineers also looked at ways to improve the aerodynamics of the frame shape itself. Therefore, they decided to investigate the positioning and shape of the seat stays. They wanted to determine if the seat stays’ aerodynamic efficiency could be increased while maintaining the desirable compliance and stiffness characteristics of a traditional road bike.

The seat stays’ main role on a frame is to help with lateral stiffness. The lateral stiffness they provide helps to transfer the energy a rider generates with every pedal stroke into making the bike move forward. While stiff seat stays are excellent for energy transfer, they can negatively impact rider comfort by offering little vertical compliance, which leads to a very harsh ride.

Throughout the research-and-design phase, our engineers worked with a number of different seat stay options. As a result of the hours spent in CFD modeling and the wind tunnels, they discovered three things:

• Completely removing the seat stays offered the most vertical compliance and least aerodynamic drag but reduced lateral stiffness to an extent that was undesirable in a road bike.

• The seat stays could be designed to be both laterally stiff and aerodynamically efficient, but keeping them in the standard location did not provide the desired vertical compliance.

• Lowering the seat stays, so they did not come up as high on the seat tube, significantly improved vertical compliance.

Designed around the right positioning and shape, our new Ultralow Seat Stays have been optimized for aerodynamic efficiency, lateral stiffness, and vertical compliance. On the Diamondback IO, a rider does not have to sacrifice comfort for performance.

AERO BOTTOM BRACKET STORAGE

When it comes to in-bike storage, the Andean is the gold standard. When designing it, our engineering team utilized a number of areas within the frame to create easy-access storage, alleviating the need to tape or otherwise attach items such as nutrition and repair materials onto the bike. Removing those items not only cleaned up the turbulent air flow they caused, the in-bike storage areas behind the head tube and seat tube and around the bottom bracket area also provide an aerodynamic benefit by improving the laminar flow across the frame.

Despite the aero benefits of in-bike storage, the extra material that is needed in some areas for that storage has a weight penalty. Keeping in mind the need to balance the characteristics of a time trial or triathlon bike with those of a road bike, our engineering team had to be more cognizant of weight than on the Andean.

After hours of CFD and wind-tunnel testing, the engineering team agreed that storage in the bottom bracket area would be ideal on the IO. It offers the rider the greatest advantage in terms of the ratio of aerodynamic efficiency versus weight.

THE COCKPIT: INTEGRATION + FUNCTIONALITYA great aerodynamic frame design can be spoiled by a lack of attention to detail. Our engineers stayed focused on the small details that make a big difference to both aerodynamics and rider experience.

AERO HANDLEBARThe handlebar is one of the first areas of the bicycle system to address the wind. This means it can have a significant impact on how the air flows across the entire system. Over recent years, a number of manufacturers have designed proprietary handlebar systems to optimize for aerodynamics. While this is great from a performance perspective, proprietary systems typically offer little flexibility in terms of comfort, fit, or rider preference.

In order to meet our aerodynamic performance requirements without sacrificing rider experience, we tasked our engineering team with developing the IO to work with the leading aero bars on the market. We wanted the IO to provide the aero benefits we were looking for without making riders dependent on a proprietary system.

Our engineering team reviewed the leading bars on the market for aerodynamic performance, functionality, comfort, and fit. Based on those criteria, Zipp’s SL-70 Aero handlebar was chosen and used throughout the research and design phases for the IO. As a result, the IO’s stock handlebar is the SL-70, and the bicycle system performs best aerodynamically with it. That said, the bar can be removed, allowing the rider to use a bar that may better meet their comfort or position needs without paying a significant aerodynamic penalty.

COVERT ROUTING PROCESSFirst introduced on TT/triathlon bikes, internal cable routing made its way onto road frames over a decade ago. Since then it has practically become standard on all aero road frames, including the Podium. When designing the IO, our engineering team reviewed our existing internal cable routing method and sought to improve it, which led to the development of the Covert Routing Process (CRP) designed around a proprietary stem.

The internal cable routing we developed for the Podium is in line with current industry standards. The cables are routed from the shifters along the handlebar and then down to the front brake, top tube, or downtube, depending on their destination. While this helps with aero efficiency along the frame, it creates aerodynamic drag at the front of the bike. We were determined to find a better routing method that could work with a majority of the aero handlebars on the market.

After hours of research, design, and testing, our engineering team created the CRP, a system that keeps cables nearly hidden, from the shifters all the way through to the brakes and derailleurs. The CRP brings the cables from the shifters through the handlebars and out the bottom, next to the stem. The cables are then routed through the bearing cover and fed through the frame to their final destination. The area of cable that is exposed between exiting the handlebars and entering the bearing cover is hidden from the wind using a cable cover that affixes to the bottom of the stem.

AERO TOP TUBE STORAGEThe storage compartment in the bottom bracket area is an essential component of the SpeedCore aerodynamic advantage, but it is hard to access while riding. While it’s an excellent solution for storing repair kits, tools, etc., it is not ideal for nutrition items that need to be accessed during each ride. Instead of assuming riders are content to tape nutrition packets to the top tube or stuff them in a jersey pocket, our engineers were convinced a better solution was available.

Again relying on knowledge gained during the development of the Andean, our engineers began looking for ways to incorporate top tube storage into the IO. This storage needed to be easily accessible without negatively impacting the aerodynamic flow or structural integrity of the frame.

The end result is a top tube storage compartment just behind the handlebar. This compartment is easy to access throughout the ride and large enough to accommodate a variety of nutrition options. When we showed our new top tube storage to industry vet Dan Empfield, he exclaimed, “Why doesn’t every manufacturer have top tube storage? Almost every rider carries snacks, and nobody has a real desire to put them in their sweaty jerseys.”

VERSATILITYThe IO offers true versatility to endurance athletes. For base miles and hill training, the layback seatpost provides the geometry of a traditional road bike. For racing and race-specific training, clip-on aero bars can be attached and the seatpost can be oriented toward the front for triathlon geometry. By altering the setup, the same bike can be used for draft-legal and non-draft events.

CONCLUSIONCountless hours of research, design, review, and refinement went into the IO. By focusing on the SpeedCore and cockpit areas, our engineering team was able to design the IO to be 20%* more aerodynamically efficient than the Podium, and only 10%* slower than the Serios. The IO achieves our goal of offering significant, proven aerodynamic advantages along with the responsive handling qualities of a road bike.

Push yourself forward on the Diamondback IO.

*While currently the IO has only been tested at speeds around 30 miles per hour, our experience with the Andean, Serios, and redesigned Podium lead the engineering team to expect a similar performance benefit across a broad spectrum of riding speeds.

Airfoil Comparison: This is a test conducted at the University of Toronto Institute for Aerospace Studies (UTIAS) 0.3m wind tunnel comparing full-scale bicycle downtube cross sections. The “flat” test specimen is a conventional smooth-walled airfoil similar to one used in the Diamondback Podium. The “Diamondback Wake Control” test specimen is an airfoil with inverted ‘vortex generators’ at the trailing edge. The pattern is custom-designed to suppress the trailing turbulent wake commonly found in truncated (kamm-tail) airfoils. The tested velocity is 30mph. The yaw sweep is +/- 20 degrees following a custom Diamondback testing protocol. Results are shown in CdA at Standard Temperature and Pressure.

This is a tested conducted at the San Diego Low Speed Wind Tunnel (LSWT) comparing full-scale rapid prototype of the Diamondback IO and the Diamondback Podium Disc. The tested velocity is 30mph. The yaw sweep is +/- 20 degrees following a custom Diamondback testing protocol. Results are shown in both grams of drag and CdA at Standard Temperature and Pressure.

GEOMETRYAs a Ready Ride model, the IO ships FREE and arrives 95 percent built so you can assemble it yourself in four easy steps.

Learn more about the IO at ride.diamondback.com/io.

GEOMETRY (MM) 50 52 54 56 58 60STACK 526 535 548 560 574 594REACH 377 380 383 400 411 417HT LENGTH 120 130 140 155 170 190REAR CENTER 410FRONT CENTER 576 582 582 601 617 628WHEELBASE 975 981 981 1001 1017 1028BB DROP 73 72 72 70 70 70ST ANGLE (DEGREES) 75.8 75.8 75.5 75.5 75.5 75.5HT ANGLE (DEGREES) 72 72 72.8 73 73 73TT (EFFECTIVE)* 510 515 525 545 560 570TT EFF. (FORWARD POSITION) 484 489 499 519 534 543TT EFF. (REAR POSITION) 537 541 551 572 587 598FORK LENGTH 370FORK OFFSET 45

* Frame is designed around a 32mm offset seatpost that can be run forward or rearward.

CUSTOM STUDIODiamondback’s Custom Studio is an online tool that allows to you customize the IO to your exact specifications. Our expert bike mechanics build everything by hand in our dedicated in-house studio near Seattle, Washington. Custom Studio orders can be shipped to over 100 countries and ship free within the continental U.S. Final assembly is quick and easy.

Visit the Custom Studio at custom.diamondback.com.

Sample Build Options:

SRAM Force 1X w/hydro / Vision Trimax wheelset

Ultegra Di2 w/ hydro disc / Zipp 302 car-bon wheelset

SRAM Red eTap / Zipp 454 NSW wheelset

Dura-Ace Di2 w/ SRAM Power Crank / Enve SES 5.6 wheelset

PRICE $3,999.99 $5,599.99 $9,119.99 $9,749.99

FRAME IO Carbon Frame Disc IO Carbon Frame Disc IO Carbon Frame Disc IO Carbon Frame Disc

DRIVETRAIN/ BRAKES

Force 1x Road with SRAM Force 1x HRD Road Disc brakes

Ultegra Di2 R-8050 w/ Ultegra Road STI/Hydraulic Disc brakes

SRAM Red eTap Road w/ SRAM eTap HRD Road Disc brakes

Dura-Ace Road w/ SRAM Power Crank and Dura-Ace Road STI/Hydraulic Disc brakes

WHEELSVision Trimax 30 w/ Continental Attack/Force tires

Zipp 302 Carbon w/ Continental Attack/Force tires

Zipp 454 NSW w/ Continental Attack/Force tires

Enve SES 5.6 w/ Continental Attack/Force tires

COCKPIT

FSA HBA Energy Wing Compact handlebar with Diamondback IO integrated stem

Zipp SL-90 Aero han-dlebar with Diamond-back IO integrated stem

Zipp SL-90 Aero han-dlebar with Diamond-back IO integrated stem

Enve Aero Road han-dlebar with Diamond-back IO integrated stem

SEATPOST/ SADDLE

FSA SL-K ITC adj. offset post w/ Prologo Zero saddle

FSA SL-K ITC adj. offset post w/ Prologo Scratch 2 saddle

FSA SL-K ITC adj. offset post w/ Prologo Scratch 2 saddle

FSA SL-K ITC adj. offset post w/ Prologo Scratch 2 saddle

EXTRAS Century poly cages Century poly cages Podium Carbon cages Podium Carbon cages