Cannondale Slice Review
While we don’t intend on solely rely on the reviews we find in magazine and online bike sites this review from Tour magazine was worth a mention.
Tour magazine’s test of the Slice
February 2009
Germany’s Tour magazine has recently become the benchmark independent tester – the one with tests that every bike manufacturer loves to win.
The editors and the magazine are widely respected because they are impartial, thorough and scientific in their testing approach.
Last month the editors tested seven* multisport frames (in alphabetical order):
•Cannondale Slice
•Carbonsports Total Eclipse
•Focus Izalco Chrono
•Giant Trinity Advanced
•Kuota Kueen-K
•Scott Plasma LTD
•Storck Aero
*(Cervelo declined to provide a bike for the test.)
Aerodynamic test methodology:
•For each frame, they replaced the stock wheels with a Cosmic Carbone
wheelset during aerodynamic testing to isolate drag and standardize the
laminar flow measurements caused by the wheels.
•Note that they also tested complete bikes, but swapped stock bars for Profile
C2+ Aero bars to put rider controls in an identical position during wind tunnel
testing.
Wind tunnel tests were then performed with three variations:
•Complete bike without rider, direct headwind speed of 45Km/h
•Complete bike with rider, spinning wheels, headwind speed of 45Km/h
•Complete bike with rider, spinning wheels, headwind/crosswind with 10-
degree offset at 45Km/h
Part I: Aerodynamics
Results
•Against this tough field and rigorous test process, the Slice earned
maximum possible points in the aerodynamic category.
•The Slice frame/fork generated 2.5 to 9 Watts less drag than most of
its competitors.
•This translates into 30 – 120 seconds of savings over the course of
an Ironman event. (This assumes an elite athlete who can maintain
45 km/hr average speed over the entire event which would require a
power output of 335 Watts !!)
Here’s what else the editors had to say:
“Considering the radical tube dimensions and the agreeably low set
weight, the stiffness values of the frame are also great.”
“When viewing the frame from above, you don’t require a whole lot of
imagination to be reminded of a razor blade, the more so as the aero-
shaped down tube is not particularly thick itself.”
As proven by the editors, the Slice frame/fork has many aerodynamic
features that lead to faster race times.
But to focus solely on frame/fork aerodynamics doesn’t tell the whole
story; in real-world riding, the bike and components cause less than
30% of the drag, while the larger frontal area of the rider/helmet causes
more than 70%.
Myriad other “real world” factors should also be considered:
Friction, inertia, rolling mass, kinematic frame response, wind speed,
rider weight, rider position, rider power output, gravity, and many more.
On level courses, minimizing aerodynamic drag is important at speeds
above 15mph. But for triathletes riding up inclines, overcoming the force
of gravity outweighs aerodynamic gains.
This means that lowering the total bike mass is also vitally important.
Tour magazine agrees. Long-time Tour tester – and avid triathlete —
Dirk Zedler has quipped about his “seven sports rules.”
In Zedler’s list, Rule #6 proves our point:
“If the mountain is too steep, you are too weak or too heavy.”
(None of his rules mention aerodynamics!)
Tour magazine also weighed framesets. The result?
The Cannondale was the lightest of the group, beating the Kuota by
15 grams and the Scott Plasma by nearly 100.
Part II: Weight
•When it came to the weights for the
complete bike, the Slice was the
lightest by 200 grams.
•The average weight of the other
bikes was 7.9 kg (17.4 lbs) compared
to 7.1 kg (15.65 lbs) for the Slice.
Bike weight (Kg)
Cannondale Slice 7.1
Carbon sports total eclipse 7.9
Focus Izalco 8.5
Giant Trinity advanced 8.7
Kuota kueen-k 7.3
Scott Plasma 7.4
Storck Aero 7.5
This is no minor point of differentiation.
Every gram that can be stripped from frame weight has the potential to
shave significant times during Ironman-distance races.
Case in point: Aboard the Slice, triathletes could shave up to 41.5
seconds over the 112-mile bike leg of the Kona Ironman!
– Kona Ironman
– The course is always rolling and low weight is a
big advantage
• Athlete – 250 Watt average power output
• Reduction of 500 grams would mean 20.7
seconds savings!
• Reduction of 1000 grams would mean 41.5
seconds savings!
• The frameset of the Slice alone achieves 800
grams of savings!
Then we did the same calculation for time trial athletes.
Using Liquigas rider Ivan Basso’s power output, we determined
that by riding the Slice, he could shave up to 25 seconds over the
38-mile stage 12TT in this year’s Giro!
– 2009 Giro Stage 12 TT
• 30.6k of climbing out of 61.7k
• Basso – 400W
• Reduction of 500 grams would mean 13
seconds savings!
• Reduction of 1000 grams would mean 25.5
seconds savings!
Part III Frame Comfort:
The TOUR-method uses a defined
force applied to the frame with the fork
mounted; deflection is measured
where normally the rider’s sit bones
would be. The test is dynamic and
therefore non-destructive. Credit: www.zedler.de
Cannondale has performed in-house testing similar to Zedler’s
methods to gauge the kinematic response of the Slice’s SAVE
features.
Our test results are also verified by our athletes. They value the ability
to remain in a lower tuck position longer than on other bikes, and they
come off the bike ready for the run.
Here’s what one athlete had to say about the Slice following long-term
ride testing:
“I feel super relaxed and powerful down in the time trial position, and
have even gone a little lower than I was before. The [Slice] is incredibly
smooth, very responsive and takes the strain for me - eliminating any
vibrations and leaving my legs stronger and fresher for the run.”
- Ironman World Champion, Chrissie Wellington
The results by our sponsored athletes prove the combination of low bike
weight, superior aerodynamics, and vibration-damping technology can
help athletes win:
•Chrissie Wellington - GB, 2x Ironman World Champion.
•Mirinda Carfrae - AUST, 4x 70.3 champion.
•Sandra Wallenhorst - GER, 3rd 2008 IM World Championship.
•Ronnie Shildknecht - SUI, 2x IM Switzerland champion, 4th 2008 IM
World Championship.
•Stefan Riesen - SUI, Winner IM France and Switzerland.
•Jose Jeuland – FRA, 4TH at 2008 IM France.
•Olivier Marceau – FRA, 2008 European X TERRA champion –5TH at
XTERRA World championship.
•Miki Weiss – AUS, 2nd at 2008 Word championship XTERRA in Maui.
•Tim Berkel – AUST, won IM W Austrailia.
Key messages:
1. Lower bike weights = faster race times!
The Slice was the lightest in Tour’s tests by a
significant margin.
2.Aerodynamics do matter, and the Slice’s
aerodynamic values are class-leading
according to third-party tests.
3.Comfort is critical to triathletes. The Slice’s
Aero Vibration Damping allows them to stay
lower for longer periods, and keeps their
bodies fresher for the run.
Frame
•High modulus unidirectional full carbon fiber frame.
•Optimum performance with comfort.
Head Tube
•Monocoque construction and size-specific.
•Getting the rider into a lower, narrower, frontal position is key to
reducing drag.
Horizontal Spear Top Tube
•Bladder molded with internal cable routing. Carbon overwrapped and
bonded to head tube.
•Narrow cross section is light and allows proper knee position to get
rider in aero position.
Speed Shadow Seat Tube
•One-piece bladder-molded construction. Co-cured to bottom
bracket/chain stay assembly.
•No brake bridge to create drag over rear of the frame and rear wheel.
Down Tube/Fork
•Bladder-molded down tube. Carbon overwrapped and bonded to head
tube.
•Extremely narrow 30mm width and optimized 79mm height (UCI legal
limit is 80mm) with internal shifter cable routing.
•Designed as a system with fork to improve aerodynamics.
BB/Chain Stays
•Oversized one-piece bottom bracket and chain stay, co-cured to
down and seat tube. Eliminates overlap joints and reduces
weight.
Seat/Chain Stays
•Slice Aero Vibration Elimination Technology - S.A.V.E - built into
the chain/seat stay system to eliminate vibration from road shock
that occurs when using deep section wheels.
•Razor thin aero profile seat stays reduce aerodynamic drag and
offer compliancy without a sacrifice in efficiency.
Multi-Position Seat Post
•78 degree (tri specific) or 73 degree (UCI legal)
5 Frame Sizes
51, 54, 56, 58 & 60cm
