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The Science is Clear

Smoother is Faster

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Suspend the Rider, Proven.

Diverge STR System

Heaven above, hell below.

It has long been clear to the team at Specialized thatmaking the rider more comfortable translates into
a better ride. Athletes perform at peak levels longer
when they can tame the terrain and focus on power. But
how do you create compliance without compromising
performance?

But we knew we had to go further and balance thecompliance in the rear of the bike, too. Those bunsonburner-baddies in the Specialized Science Club got towork scheming the fastest, most dialed, efficient, andcomfortable system they could imagine. And in 2022,
Rear FutureShock was born.

You suspend the rider, of course. Separating the rider
from impacts and vibration has long involved suspension
forks, multi-pivot frame designs, and lots of heavy
components.

Our riders know already that keeping them comfortable
improves their ride, keeps their bodies fresher longer,
and allows them to perform at their peak withoutdistraction. It’s hard to argue with seven Paris-Roubaix
wins, after all. But some riders were skeptical. They
said comfort’s nice, but that requires compromise topreserve performance.

The Specialized Science Club, a combination of allof Specialized’s different Ride Science teams, and aunique celebration of science geekery for over fifty
years, knew we could do better; in 2016, the Specialized
Science Club sealed themselves in the lab to devise anevidence-based, performance-first solution to powerrobbing bumps and chatter. FutureShock, which soaked
up vibration and impacts at the front of the bike with arevolutionary and lightweight compliance design, wasborn.

The data is in. Are we crazy? Is it all just hype? Not
according to the numbers. The study showed Diverge
STR is every bit as efficient as a rigid bike, and it’s asignificant improvement when it comes to rider comfort.
But the big news? Smoother is, truly, faster. Thenumbers prove it: the STR-equipped bike decreases
rolling resistance created by external forces.
In other words, STR is a big win —by a comfortable margin.

They called us crazy. We love it when they call us crazy.
To prove that suspending the rider over the chatter andchunder beneath them did indeed improve ride quality
without sacrificing any performance, we sent a Diverge
STR to the German Sport University Cologne’s Institutefor Biomechanics and Orthopedics. This third-party
testing would prove, or disprove, with hard data
whether STR improved ride quality while maintaining orimproving performance.

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INTRODUCTION

Innovation lies at the heartof every Specialized bicycle.
As the needs of the rider change, we innovate
to solve the rider’s problems, and also transcend
the performance baseline to create technicalperformance benefits for the discerning rider.
For nearly a decade, it has been clear to theminds at Specialized Science Club that smootheris faster. That ethos led engineers to STR, giving
them the opportunity to rise above the noise —both figuratively and literally.
That meant isolating the rider from the harsh
impacts that can slow them down without
sacrificing any performance aspects of the bikeitself. Enter FutureShock, the foundation uponwhich STR is built.

1990

FutureShock development and implementationon Specialized mountain bikes

2004

Zertz elastomer inserts integrated into roadbike frames and forks to dampen vibrations

2005

Tom Boonen wins Paris-Roubaix on a Zertzequipped Specialized

2016

Front FutureShock released to the world on theS-Works Roubaix

2018Peter Sagan wins Paris-Roubaix on board
a FutureShock-equipped S-Works Roubaix

2021

Ian Boswell and Laurens Ten Dam go 1-2 at Unboundon Future Shock Equipped Diverge

2022

Specialized introduces Rear FutureShock on the Diverge
STR, delivering the ultimate expression of our Suspend
The Rider philosophy

2023

Laurens Ten Dam takes the Elite Men’s 200-mile second
place at Unbound Gravel on the Diverge STR; Sarah
Sturm finishes in third place in the women’sElite 200-mile race.

FutureShock and Rear FutureShock suspend
the rider, vastly reducing the amount of impacts
that reach the body. By incorporating front
FutureShock above the head tube, your frameand fork remain rigid, maintaining efficiency andsharp handling. The suspension then absorbs
vertical movement between the frame and therider, keeping the rider more comfortable.
On top of that, FutureShock increases handlingaccuracy by ensuring the front wheel stays incontact with the ground longer.
Rear FutureShock operates on a similar
principle: maintaining the structural rigidity of
the frame for efficiency benefits, while separating
the rider from jarring impacts — above the frameitself.
The result is a system that eliminates fatigueinducing impacts on the rider while maintaining
structural stability and responsiveness thatdefines the Specialized ride.

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VA L I D AT I O N

German Sport University
Cologne’s Institute forBiomechanics andOrthopedics
The independent STR validation study was conducted byDr. Josef Viellehner and Professor Dr. Wolfgang Potthastof the Institute for Biomechanics and Orthopedics at theGerman Sport University Cologne.
The stated goal of the study was to “understand if andhow vibrations and a damping system influence therider’s performance.”
Two Specialized Diverge STR bicycles were used inthe testing: one Diverge STR set up with fully-active
FutureShock components, and one Diverge STR withfully locked-out, inactive FutureShock components.
20 riders were tested during the course of the study,
which ran for six months. 17 male and 3 female riders
were tested. Each rider was tested on three separate
occasions. The riders tested were representative of theDiverge STR rider: strong, competitive, non-pro racers.

Performance Analysis

Bump-External
Driving Resistance

Movement Analysis

During each module, each rider’s cadence, heart rate, power, and Rateof Perceived Exertion (RPE) were recorded and analyzed.

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P E R F O R M A N C E A N A LY S I S

STR does not adversely
affect power output.
P E R F O R M A N C E A N A LY S I S TA K E A W AY

Study results concluded that FutureShock does
not rob the rider of any power output. This wasdetermined by comparing each rider’s averagepower over the five intervals conducted in testing.
Vibration reduces power output by around 3% over the entire testing on botha rigid bike and an STR bike.
Results indicated that there was no difference between power output on thefully active (damped) Diverge STR versus the locked-out (non-damped) Diverge.
Notably, no significant differences in heart rate were uncovered throughout theintervals. This indicates that activating STR has no negative effect on power.
Interval 4 is a notable exception; RPE dropped on the fully-active STR bikeduring interval 4, possibly due to riders ‘settling in’ to the testing protocol.

METHOD1.

Goal was to achieve highest possible
average power output per interval

2.

Testing took place within eightdays, with at least one day of rest inbetween

3.

Performed on vibration machinewith no vibration; then, withvibration active on both the fullyactive bike and the fully-locked-out
bikeDuring each module, each rider’scadence, heart rate, power, and Rate ofPerceived Exertion (RPE) were recorded
and analyzed.

On average, RPE was significantly lower on the fully-active STR systemthroughout intervals.

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P E R F O R M A N C E A N A LY S I S

STR significantly increases
rider comfort bothobjectively and subjectively.
OBJECTIVE MEASUREMENTRIDER PERCEPTION

The results from accelerometer data show thatthe Diverge STR with FutureShock fully active
significantly reduced impact and other movement
at the hands, neck, shoulders, and low back, ascompared to the Diverge STR with FutureShockcompletely locked out.

Riders reported that they felt the Diverge
STR with fully active FutureShock was notably
more comfortable than the Diverge STR withFutureShock completely locked out. Riders also
noted lower RPE throughout testing on the fullyactive FutureShock bike.

STR vibration exposure reduction at each
3D accelerometer:

That’s because impact absorption reduces
stresses on the body, as well as muscular
activation that leads to fatigue. Less fatigue leads
to a perception of increased comfort.

•Hands = 46.3%•Shoulders = 28.7%•Head and neck = 23.2%•Low back = 11.4%

METHOD

This facet of the study is notable because
it is rare for rider perception and objective data
to line up almost exactly, as it does in this case.

1.

Three bike and vibration
combinations were tested at threedifferent pedaling intensities.

2.

Riders maintained cadence
between 85-90 RPM and power wasnormalized to body weight.

3.

After warm-up, measurements
were started as power and cadence
stabilized.

4.

Three measurements were taken:
exposure to vibration, perception ofvibration, and muscle activation.

5.

Tests were randomized on the novibration setting, the fully-active
damping setting, and the locked-out
damping setting.

Rider perception of STR vibration reduction:

Damping also reduced impact on the low backmost notably at low and medium cranking
intensities. Legs were largely unaffected by STR,
since most vibrations the legs will experience
are transmitted through the pedals and cranks,
which are not decoupled from the bike.

•Seating area (saddle) = 28.5%•Hands = 43.9%•Head = 46.0%•Feet = 14.0%

Estimated Performance Gain of the STR System

Reduction in Rolling Resistance [W]1210864Suspension

20RigidBump Distance [m]10787674727

Comparing the reduction of rolling resistance of the Diverge STR (blue line) and a non-suspended bike. The Diverge STR significantly reduces rolling resistance(measured as watts saved) as bumps become more frequent; the non-suspended bike does not reduce rolling resistance, regardless of bump spacing.

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STR decreases rollingresistance created byexternal driving forces.
OBJECTIVE MEASUREMENTMETHOD

The results of the test show that the rider moves faster with less effort
when braking impulses are mitigated.
•Testing concluded that STR reduces speed loss per bump by 4%•

The wattage savings of the STR system depends on the numberof bumps encountered during a specific timeframe.

•The study concludes that when a bump is encountered every
10 meters (or 2 seconds), the rider saves 3.4 watts.

•The study concludes that when a bump is encountered every
3 meters (or 0.8 seconds), the rider saves 11.3 watts.

A bump study was conducted to measure deceleration on both thefront and rear wheels. A 4cm x 4cm bump was mounted to a force
plate to simulate a large impact a bicycle is likely to encounter inregular riding scenarios.
The force plate then measures ground reaction forces. When
combined with the amount of time the wheel hits the bump, theresulting measurement defines external driving resistance — known
as an impulse. Forces were measured horizontally — known as braking
forces — as well as vertically.
Impacts were measured when the front wheel hit the bump, and when
the rear wheel hit the bump. The cumulative effect on braking impact
equals total impulse. The forces from the front and rear wheels are
not averaged; rather, the forces are added as a total sum.

Riders noted a significant reduction (3.2%) in the effort required to complete
maximal power tests. This, combined with comparable power production,suggests that STR lowers the effort required to pedal over bumps.

When the bicycle encounters a bump, the result is a reduction in
driving forces. In order to regain that driving force, the rider has toinput more power.

Rolling Resistance for Bumps @ 5 m/s

120

Bump Rolling Resistance 6.-100806040200

Bump Distance

Suspension

Rigid8+Suspension

Rigid6+

Suspension

Rigid4+

The Diverge STR’s wattage savings over a non-suspended bicycle. While traveling at five meters per second, the Diverge STR reduced rolling resistance atbump distances of 8 meters, 6 meters, and 4 meters. The most significant savings occurred at shorter bump distances; this illustrates that the advantages ofthe Diverge STR increase as the terrain gets bumpier.

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The lab data concluded that there are concrete benefits to STR.
But what about in real world conditions? The Specialized Science Clubgot to work once the lab results were in to see if they would translate
to real rides outside.

B U M P A N A LY S I S TA K E A W AY

The results of the outdoor testing mirrored thatof the lab testing. Of note, STR reduces bumpinduced rolling resistance by 8% (6.1 watts), giving
the rider a total performance benefit of around 3%.
The data is broken down according to rider type:
Super Strong Rider, Strong Rider, and Normal Rider.
Each rider was tested on Rough Road and Moderate
Roughness Road, with time savings calculated over
10km of Rough or Moderate Roughness road.

METHOD•

A test run was constructed with a series of bumps thatmeasured 37mm (2 x 2 inches). This is smaller than the lab
bump so the Specialized Science Club could create a testing
ground with a series of bumps the rider would encounter
quickly.

•Riders pedaled over the bumps•

The test course was slightly inclined so the rider had
to pedal in order to maintain speed•

Riders needed to maintain a constant speed over test runs,
within a quarter-second variability•

Wind data was recorded; the wind speeds were the samefor all bikes and riders tested.

•While a force plate was used in the lab, outdoor testing
required the use of the rider’s power meter to identify how
much power was required to ride through the seriesof bumps.

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FIELD TESTING

Rough Road

Super Strong Rider
360 W at 70 kg (+10kg bike)

Strong Rider
240 W at 70 kg (+10kg bike)

Normal Rider
240 W at 70 kg (+10kg bike)

Diverge27.6 kph / 00:21:45

24.3 kph / 00:24:39

20.7 kph / 00:29:02

STR

28.3 kph25.0 kph21.4 kph

Time Saved over 10km

34.3 Seconds

43.7 Seconds

58.8 Seconds

Moderate Roughness Road

Super Strong Rider
360 W at 70 kg (+10kg bike)

Strong Rider
240 W at 70 kg (+10kg bike)

Normal Rider
240 W at 70 kg (+10kg bike)

Diverge34.7 kph / 00:17:18

31.6 kph / 00:19:00

28 kph / 00:21:27

STR

34.9 kph31.9 kph28.3 kph

Time Saved over 10km

7.8 Seconds

9.8 Seconds

13.1 Seconds

On a moderately rough road with small but frequent obstacles a super-strong
rider will save nearly 8 seconds on the Diverge STR, and a normal rider willsave just over 13 seconds. The Diverge STR benefits increase most for riders
who need it most.

On a rough road with frequent and significant obstacles the Diverge STR willsave a super strong rider nearly 35 seconds, and a normal rider will savealmost a full minute, according to real-world testing conducted bythe Specialized Science Club.

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CONCLUSION

Ultimately, the Diverge STR reduces external driving resistances,which proves the notion that STR increases rider performance throughenhanced comfort and lower rolling resistance.

Improved Rider
ComfortSubjective Vibration
Reduction

Objective Vibration
Reduction

Movement analysis revealed STR improves
rider comfort. Vibrations activate some muscle
groups, thereby contributing to fatigue anddiscomfort. Vibrations can also reduce the rider’spower output slightly and systematically during
repeated short-term high-intensity efforts.

The study concluded that damping systematicallyreduced the vibration exposure of certain muscle
groups in the upper body, as well as in the hands
and arms.

Rider perception also noted reduced vibration
exposure in line with the objective data. Thismeans that the STR system improves rider
comfort both objectively and subjectively.

Reduction in Rolling
Resistance

Reduction in External Driving
ForcesNo Adverse Impact to Power
OutputReal-world testing conducted by the Specialized
Science Club corroborate lab testing results. STR
reduces bump-induced rolling resistance by 8%.
That’s around 6.1 watts.

Bump analysis revealed The STR system
positively affected bike-surface interaction.
External driving forces were reduced when
passing over small bumps. Braking and vertical
impulses generated by the front and rear wheels
during the rollover testing were significantly
reduced. The STR system therefore reduces
rolling resistance over bumpy terrain.

Performance analysis revealed STR does notadversely affect power output. The performanceof the riders on the fully-active Diverge STR andthe locked-out Diverge STR was comparable.
Damping had no detrimental effect onperformance. While damping vibration does notenable more rider power output, it does not rob
the rider of power, either.

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