With all due respect to history, tradition,

status quo, rules, guidelines, or best practice.

Without preconceived notions of what the

fastest bike in the world should be.

This is no one-off, vanity project, or simply

another bike. We didn’t just set out

to design something fast.

We set out to change a sport.

This is Andean

TRADITION YIELDS TRADITIONAL RESULTS

WE WANTED MORE

THE DIAMONDBACK SPIRIT IS ONE OF INNOVATION AND GROWTH. We are driven to

create, whether it’s new bikes, experiences, or methods of doing business. It’s not in our nature to

coast or to rest on our laurels. Our journey from scrappy BMX company to making high end road

race bikes would not have been possible without this drive being part of our DNA.

Not only did the Serios emerge a blazing fast bike, but it allowed us to strengthen our

partnership with Kevin Quan Studios and expand our research capabilities. Establishing

a foothold in triathlon opened our eyes to an opportunity we couldn’t ignore: triathlons

are being raced on modified road bikes. We found that a purpose-built bike, one that

was built specifically for the conditions of triathlon, was sorely absent. We feel it’s time

to keep pushing.

SERIOS AF

During the design and testing phase for the development of the Andean, our engineering team worked

extensively with Dr. Philippe Lavoie, of the University of Toronto Institute for Aerospace Studies (UTIAS).

This provided Diamondback with unparalleled access to a team of grad students eager to bring their state

of the art thinking to the bicycle industry, as well as the half-scale tunnel they operate.

RESEARCH

The Serios was a bike designed primarily as a UCI-approved TT bike for our professional road race team, Rally (formerly Optum). Faster than anything before it, the Serios is known for excelling on the twists and turns of real world race courses. Michael Weiss and Rachel McBride have taken advantage of the Serios’s performance in side winds to set course records and stand on podiums. The Serios project was a success on and off course.

Instead of adapting a bike from another purpose, we’re taking a gamble to cater to a relatively small group of racers who are looking for more out of their bikes. We are confident the results will be undeniable.

UNIFORMITY OF FLOW - One of the biggest challenges

with testing is repeatability. To ensure repeatability

in a wind tunnel requires constant wind speed. The

challenge is that wind can be very unpredictable, even

in a controlled environment.

By testing in a half-scale tunnel, there is smaller space

and fewer variables to deal with when controlling

the flow. This results in higher repeatability and more

accurate testing.

LOWER TURBULENCE - The smaller size of the half-

scale tunnel allows the UTIAS team to have significantly

more control. This allows for the level of turbulence in

the flow field to be adjusted so it is more representative

of real world riding conditions. Not only that, they can

adjust the turbulence to resemble different riding

conditions, such as riding: solo, at the front of the

pack, in the middle of the pack, and at the back of the

pack. Having access to this level of data allows our

engineering team to really design the frame to perform

well in all conditions, or be optimized for a specific

environment.

LASER DIAGNOSTICS TESTING - Aerodynamic

performance can be significantly affected by even

the smallest of disturbances in flow. In addition to the

standard testing tools and functionality of most wind

tunnels, the team at UTIAS also operate a laser that

allows for very specific diagnostic testing.

Our engineering team is able to work with UTIAS to

not only measure the performance of the entire frame,

but, through use of laser testing, show the flow field

around specific elements such as the bottom bracket,

the cockpit, or rear triangle. This precise level of detail

allows our engineers to further refine their design for

optimal performance.

The University of Toronto’s half-scale wind tunnel is a

one-of-a-kind facility that is uniquely positioned to refine

the discoveries found during the Serios project. It isn’t

made for race cars, airplanes, or space ships, it has

been optimized for our bikes. Its smaller format enables

a higher level of quality control with fewer variables to

account for, something that’s surprisingly difficult even

in a wind tunnel. We painstakingly created half-scale

models, giving us a very high level of repeatability

and control.

Dr. Lavoie and his graduate students came into the

project with open minds and fresh ideas, a huge

advantage for the project. Their experience in

aerospace design is a refreshing change from bike

people who’ve “seen it all,” and they were encouraged

to seek out solutions in unorthodox ways.

While a number of bike manufacturers perform varying

levels of aerodynamic testing in large format wind

tunnels, the engineering team at Diamondback have

found several benefits by starting first with the half-scale

tunnel:

So, how do we fit a complete bike and rider into a small format wind tunnel? Beginning

with the Serios, our engineering team introduced stereo lithography (SLA) to our

production process. During this step, they made elements of the frame using a rapid

prototyping process. While the element developed would not be weight bearing, it

allowed our engineers to test its aerodynamic properties of it. For the Andean, we took

the process to the next level.

Bike specific Apparatus - As with any type of testing, the results are only as accurate as the scale being used for measurement. Before entering the UTIAS tunnel, our engineers worked with Professor Lavoie and a number of his grad students to develop a scale for the specific needs of a triathlon bike. While a number of other manufacturers use a standard scale, or make small adjustments to test a bicycle, very few have a scale designed for their specific needs.

After using computer modules, such as Computational Fluid Dynamics (CFD), to design the Andean to the desired performance levels, our engineering team used the SLA process to develop a 50% scaled prototype of the complete bike. To provide even more accurate testing, we used a member of team Rally Cycling as a model to develop an SLA version of a rider. This allows the engineers to now enter the tunnel with a true representation of a rider on the frame.

In addition, the frame itself was designed to be modular and scalable. This allows the

Diamondback Engineers to test different variations of the same elements accurately

and quickly. For example on the Andean, we tested 30 variations of the front fork.

Using the SLA model and the UTIAS tunnel, our engineers were able to test a fork,

measure the results, and then remove the fork and install the next variation for testing.

At the end, we were able to compare the performance of all the options and select the

most optimized version for the frame.

WITH EACH PEDAL STROKE, A RIDER

ENCOUNTERS SEVERAL FORCES OF

RESISTANCE. THE LARGEST RESISTANCE IS

AERODYNAMIC DRAG. While the rider accounts for

80% of aerodynamic drag, the bicycle itself accounts for

the remaining 20%. The more aerodynamically efficient

we can make the frame, and position of the rider, the

less drag the rider has to overcome. This means a higher

percentage of the effort translates into real speed.

AERODYNAMICS

When we began the design for the Andean, we

took an integrated design approach. This means we

wanted to look at the rider, and all elements of the

bike (frame, wheels, crank, bars, etc.) as one system.

Often, manufacturers look at the frame in a vacuum,

without consideration for how it interacts with the

rider or other components of the bicycle. By taking

the integrated design approach, we were trying

to see the rider and bike as the wind does - one

unit fighting against aerodynamic drag. We spent

hours of CFD modeling, built hundreds of prototype

iterations, worked days and days in the wind tunnel,

and developed an SLA rider model to sit on top of

the bike.

Early on in the design process, our engineers

determined several things. The first was that our

biggest challenge would be integrating the wheels

with the frame. The wheels are constantly moving,

and competing wheel manufacturers do not have

a standard width or depth.

The second challenge was the testing itself. While

most engineering teams use different design tools to

test aerodynamic benefits of a frame, those tools are

designed to look at one single shape at a time. In order

to develop an integrated designed frame, our engineers

needed to see how one shape positions the airflow for

the second shape and third shape.

The third challenge was testing related as well. Using

CFD will only take bicycle design so far. As discussed

during the launch of the Serios, our engineers utilize

both a half-scale tunnel and a large one. Given the

benefits of the small format tunnel, our engineering team

determined it would give us the best, most accurate,

results. However, in the past, the half-scale tunnel has

only been used to test a single tube or a combination

of tubes, because it is too small to accommodate

a complete bicycle and rider.

Once our engineering team validated the need to

transition airflow from one element or shape of the

bicycle to the next, they had to determine how to

properly test and measure it, to identify the true benefit

to the rider. As mentioned, to date the tools used in

design really focused on one shape at a time and

did not account for the tandem effect our engineers

were working to design around. Working with Dr.

Philippe Lavoie, of the University of Toronto Institute for

Aerospace Studies (UTIAS), our team broke down the

simulation tools we had at our disposal. From there, we

looked to see which ones could be modified to measure

the tandem effect, and evaluated each one to test for

accuracy and repeatability. The net result is a new way

of designing not only the Andean frame, but all future

Diamondback aero-focused frames.

TANDEM EFFECTS

To address wheel integration, our engineering team

developed modeling for the leading aero wheels on

the market, specifically the HED Jet. These models

were initially input into CFD for computer testing,

and eventually developed into rapid prototypes

for wind tunnel testing. The engineers learned

the middle section of the wheel performed the

weakest, regardless of rim depth or manufacturer.

Our engineers worked to design the Andean frame

with an Aero Core philosophy. The Aero Core is the

section of the frame that sits directly between the

wheels. The Andean connects the two wheels with

one large integrated airfoil that begins with the front

wheel, transitions over the bottom bracket and exits

off the rear wheel. By doing so, the laminar flow

across the entire system is improved, reducing the

overall aerodynamic drag of the bicycle system.

WHEEL INTEGRATION & THE AERO CORE

SCALING FOR TESTINGONCE OUR ENGINEERING TEAM WERE PLEASED WITH THE

PERFORMANCE OF THE ANDEAN IN CFD, IT WAS TIME TO

MOVE OUR INTEGRATED DESIGN INTO THE TUNNEL FOR

TESTING. Based on their knowledge and experience, the preference was

to use a half-scale tunnel for the majority of the testing, before moving into

a large format tunnel for final confirmations.

In order to do so efficiently, the Diamondback engineers took a scaling

approach. Long used in aviation and auto racing, scaling involves reducing

all elements to a certain percentage of actual size. This is done to provide

accurate results in wind tunnels that are not big enough to accept full size

prototypes. The scaling must be precise, even the smallest variation will have

a significant impact on the real world performance.

Because the focus of the Andean is integrated design, scaling the frame

was only the first step. Once that was done, we needed to scale a rider to sit

on the bike. Working with team Rally Cycling, we reviewed the TT (time trial)

position for a number of the riders. Using those positions as mapping points,

our engineering team developed a model in CFD. The position was refined

to properly interact with the Andean cockpit, and then moved into the rapid

prototyping phase. The end result was a rider and frame that was 50% of

actual size. This allowed the Diamondback engineers to work with the team at

UTIAS to further test, review, and refine shapes of the Andean. Once pleased

with the results in the small format tunnel, our engineers increased the scale to

100% and moved into the large format wind tunnel for final confirmation.

ONE GLARING OMISSION FROM THE

CURRENT CROP OF TRIATHLON BIKES IS

ADEQUATE STORAGE. Triathletes are forced

to make do with their converted road bikes, taping

supplies to their frames. This practice not only

hurts the aerodynamics of the bike but can make

for a tricky situation on the road. Our professional

triathletes Rachel McBride and Michi Weiss

repeatedly brought this up as a major issue when

preparing for their races. Competitors shouldn’t have

to worry if it’s worth it to take along that extra energy

gel or sunscreen.

STORAGE

Once deciding that we were going to solve the problem of storage on the bike, we

knew where to start. We implemented storage within the monocoque frame itself,

and behind the rider’s elbows. These areas are out of the wind and large enough to

accommodate unprecedented amounts of storage. The days of pitting supplies against

capacity are over.

Andean was designed to carry Rachel McBride’s preferred cargo: two energy bars, ten gels, and salt tabs. No slowing down, no bonking.

Andean allows you to be prepared right away, with room for gels, salt tabs, and the waste packaging these generate. Fewer feed stops, more focus on the bike. Again, Andean is made to win races.

We eliminated the seat stays. This removed a surprising amount of drag-inducing surface area, addition by subtraction. Even with tripling the chainstay height to maintain a viable rear end, the gains in straight-line speed are significant. This new rear end works with the Aero Core to make the Andean even faster than predicted.

After months of research, design, testing and development, our engineering team

developed the Andean. Our initial goal was to design a frame that provided a strong

aerodynamic advantage over other frames on the market, including our own Serios. In

the end, our engineers not only delivered on that goal, but developed new processes

and procedures that will be found in future Diamondback frames, and will likely be

trickled down to some of our existing frames as well.

1 X DRIVETRAINTHE INTRODUCTION OF ROAD BIKE DISC

BRAKES SIGNALED ANOTHER TANTALIZING

POSSIBILITY FOR ANDEAN. Disc brakes

outperform rim brakes and their calipers are more easily

hidden from the wind. And given the wheels-first design

process of Andean, rim brakes just aren’t in the cards:

the future of wheel technology will undoubtedly

feature discs.

BULKY FRONT DERAILLEURS AND

AERODYNAMIC ENGINEERS HAVE NEVER

BEEN ON THE FRIENDLIEST OF TERMS.

LUCKILY FOR THE ANDEAN PROJECT,

THE TIME IS RIGHT TO DITCH THESE

ANTIQUATED MECHANISMS. It’s never made

more sense to go with a single front chainring: not only

does it get rid of the front derailleur’s weight and drag,

but it does the same for an unused spinning sprocket.

With a more streamlined bottom bracket blending into

the Aero Core, air flows much more smoothly past these

once troublesome areas.

DISC BRAKESOUR GOAL WITH THE ANDEAN PROJECT

IS NOT ONLY TO WIN TRIATHLONS, BUT TO

REVIVE THE SPIRIT OF INNOVATION THAT’S

BEEN ABSENT FROM RECENT BIKE DESIGN. By fully committing to making a triathlon-specific bike

we were free to concentrate on what makes a bike fast,

instead of what makes a bike conform. In addition to

a remarkable bike, our design initiatives created new

research techniques, workflows, and expectations. We

hope to see triathletes riding bikes that help push their

sport further, not bikes that hold them back.

Through our collaboration with KQS and UTIAS, we have

made a bike that will change the triathlon landscape.

And as the UCI relaxes their regulations, we think it’s

only a matter of time until the next Andean is admitted

as a TT bike.

Inspired by design pioneers from decades past and

contemporaries, Diamondback is proud to present

Andean.

CONCLUSION