ride life. ride giant....By far the most diffi cult road quality to isolate and quantify is what is...
Transcript of ride life. ride giant....By far the most diffi cult road quality to isolate and quantify is what is...
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road Report Card
ride life. ride giant.
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road report card:introduction/variables
Spend fi ve minutes perusing new road bikes at a local dealer and you’ll likely reach one conclusion: “They all look pretty much the same.” But while they may appear similar as they sit static on the showroom fl oor, the dynamic performance characteristics of various, similar-looking road bikes can differ greatly. It’s important to understand and consider the differences that exist beneath the visible outer “skin” of the bicycle.
Giant’s mission is to produce the most balanced, best-riding road bicycles in the world. To accomplish this goal, and to ensure that we achieve the highest standards, we developed a proprietary methodology called
the Road Report Card. This breakthrough testing standard accomplishes three primary goals: it reveals the hidden characteristicsof other road bikes on the market; it clearly summarizes the key dynamic and static differences between Giant’s road bikes and those of its competitors; and it informsand drives our engineering and development efforts.
Giant didn’t set out to create a standard that focuses on laboratory-only forces. The Road Report Card goes beyond that and tests the forces that occur in real-world riding conditions.Forces that every rider, regardless of skill or fi tness, experiences on every ride.
There are threevariables that make up this test:
1. Weight 2. Comfort3. Stiffness
Makingthe Grade
While seemingly objective, frameset weight can actually be a highly subjective variable—it all depends on what is considered a frameset. Giant defi nes a frameset as:
— A size medium, painted/decaled production frame — Headset — Production fork (uncut) — All production hardware (water bottle bolts, etc.) — Front and rear derailleur hanger/clamps — Seat clamp — Seatpost (ISP or standard high-quality composite post) — No crankset or bearings
All these elements are assembled and weighed on a standardized scale at Giant’sTC (Techno Center) headquarters in Taiwan.
Looks can be deceiving. This nugget of wisdom holds true forthe road bicycle—which has featured the same “double diamond” design since its inception over 100 years ago.
weight
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By far the most diffi cult road quality to isolate and quantify is what is commonly referred to as “comfort,” or what Giant calls “compliance.” Compliance is the quantity of vibration that a frameset is able to “soak up.” When riders speak of a particular bike being more compliant than another, what they are really referring to is the frameset’s ability to absorb the multitude of vibrations delivered from the
rough pavement to their hands and backside. A frameset that is able to absorb and dissipate these vibrations is said to be more compliant than a frame that directly transfers these vibrations. The better the frameset’s vibration absorption ability, the more compliant, or comfortable, it is to ride. And a compliant bike that transmits less vibration can improve a rider’s endurance.
Giant’s Road Report Card is unique in that it is the fi rst test of its kind that effectively quantifi es and compares the compliance ofone frameset to another. Each frameset is tested for both front and rear compliance.
The front compliance test:We simulate— Frameset locked securely at the rear dropouts— Frameset loaded at the bottom bracket, top of seatpost and end of the
stem to a total of 160 pounds (average rider weight)— A single, regulated blow is delivered to a dummy hub locked at the
fork tips
We measure— Via a potentiometer placed at the end of the stem (simulating a rider’s
hand placement), the acceleration of the force is measured in g force, while the duration is measured in s (seconds).
We conclude— The lower the amount of vibration transmission transferred via the front
end of the frameset, the more compliance the frameset offers.
The rear compliance test:We simulate— Frameset locked securely at the fork dropouts— Frameset loaded at the bottom bracket, top of seatpost and end of the
stem to a total of 160 pounds (average rider weight)— A single, regulated blow is delivered to a dummy hub locked in the
rear dropout
We measure— Via a potentiometer placed at the top of the integrated seatmast (simu-
lating a rider’s backside placement), the acceleration of the force is measured in g force, while the duration is measured in s (seconds).
We conclude— The lower the amount of vibration transmission transferred via the rear
end of the frameset, the more compliance the frameset offers.
These two compliance figures (front andrear compliance) are averaged to result inthe frameset’s overall ride compliance.
vibration Input
fixed
weight load
weight load
weight load
vibrationoutput
comfort
fixedweight load
weight load
weight load
vibrationoutput
vibrationinput
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road report card:variables
The Road Report Card breaks the generic term “stiffness” down into two variables: steering stiffness and pedaling stiffness. These two scores are averaged to determine an overall stiffness score for the Road Report Card. Let’s take a closer look at each of these two variables:
1. STEEring stiffnessSteering stiffness can be felt under hard cornering or heavy braking and is a result of the fork, headset and headtube all fl exing under load. With steering stiffness, more is certainly better. Higher levels of stiffness allow the rider to arc more tightly, with more stability, through corners and have better control under heavy braking.
Two types of tests are performed to determine steering stiffness: a frontal stiffness test (which expresses how the front end of a frameset defl ects under heavy braking conditions) and a lateral stiffness test to determine how the front end of the bike defl ects under heavy side-to-side sprinting or cornering. Here is how each of these tests was performed.
the frontal-steering-stiffness test:We simulate— Frameset locked at rear dropouts— Perpendicular frontal force applied to fork dropouts, which simulates braking
We measure— Defl ection at dropouts in N/mm (Newtons per millimeter)
We conclude— The higher the value, the stiffer the frameset
the lateral-steering-stiffness test:We simulate — Frameset locked at rear dropouts— Torsional side force is applied to fork dropouts, which simulates cornering
We measure— Torsional defl ection at dropouts in N/degree
We conclude— The higher the value, the stiffer the frameset
stiffness
FORCE >fixed
< FORCEfixed
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Loosely fixed
fixed
< FOR
CE
45º C
rank R
otated
Side Inclination 10º
Vert
ical
Axl
e
2. pedaling stiffnessPedaling stiffness can be felt under heavy pedaling (such as sprinting)and is a result of the side-to-side motion of the bottom bracket area.With pedaling stiffness, more is better. The less bottom bracket fl ex,the more power will be transferred through the drivetrain to the rearwheel—propelling you forward faster.
We simulate— Frameset locked securely at the fork dropouts and loosely at rear dropouts— Frameset inclined to 10 degrees — A measured force is applied to a dummy crank positioned at 45 degrees
We measure— Defl ection at the dummy crank in N/mm (Newtons per millimeter)
We conclude— The higher the value, the stiffer the frameset and better
the pedaling effi ciency
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road report card:results
WEIGHT
stiffnesscomfort
trekmadone 6.9 pro
weight: b-stiffness: dcomfort: b
WEIGHT
stiffnesscomfort
specializedtarmac sl2
weight: c+stiffness: acomfort: c+
WEIGHT
stiffnesscomfort
scottaddict sl
weight: a+stiffness: bcomfort: f
WEIGHT
stiffnesscomfort
cervelor3 sl
weight: astiffness: b-comfort: d
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READING THE GRAPHSThe three points of each triangle graph represent the highest possible scores in weight, stiffness and comfort. The ideal score is a large, perfect triangle. The grades are derived from the relative placing of each frameset’s three performance qualities against the other models (i.e., the Giant TCR Advanced SL weight compared to the other seven framesets). These grades are direct translations of the statistical information obtained through laboratory testing of 2008 competitor models and the 2009 Giant TCR Advanced SL.
CONCLUSIONWhile some framesets scored higher in a single category, none matched the all-around performance of the Giant TCR Advanced SL. It’s Giant’s mission to build the best-riding bicycles without compromising one value, such as weight, for another, such as stiffness. The results reflect the mission.
WEIGHT
stiffnesscomfort
cannondalesupersix team
weight: fstiffness: bcomfort: d+
WEIGHT
stiffnesscomfort
canyonf10 ultimate
weight: b-stiffness: c+comfort: d
WEIGHT
stiffnesscomfort
look595 ultra
weight: dstiffness: d+comfort: a-
WEIGHT
stiffnesscomfort
gianttcr advanced sl
weight: b+stiffness: a-comfort: a+
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