PERFORMANCE ON THE ROAD

 AMD technology helps to provide the Discovery Cycling Team with the winning edge in three key areas: design and development; testing and training; and communications.   

Explore the technology that has turned bicycles into sophisticated racing machines, custom designed for rider and race. Explore how data for finely-tuned strategies are gathered and relayed as coaches plot the best way to maximize team strength and exhaust the competition.  Learn how Trek engineers have used AMD64 technology to build the fastest and most sophisticated racing machines in pro cycling history. 

 DESIGN & DEVELOPMENT

The Quest Begins

The Trek story began in 1997 with Paul Andrews taking a 20-minute spin on a Trek Y-Foil road bike. The bike is black, revealing its unpainted carbon fiber tubing. Attached at three strategic spots were sensors. These sensors, affixed to the bottom bracket, the head tube and the chain stay, were wired to a small "data acquisition unit,'' a black box attached to the frame.  In effect, Andrews that day was taking an electrocardiogram of the bounces and stresses his route took up and down the hills of this Waterloo, Wisconsin farming country.  Andrews, who stands 6 feet 2 and weighs 195 pounds, had no idea at the time that his uneventful ride would ultimately benefit Lance Armstrong, a 5-foot-11, 165-pounder who just happens to be the only American ever to win the world's most difficult race, the Tour de France, five times and go onto unprecedented sixth and seventh tour victories. 

The Ride Database

The sensors were strain gauges, and the output of that day's ride was fed into a database of approximately 5,000 other rides taken by Trek testers over a dozen years.  The goal: to provide enough information on where real rides put torque and pressure on real bikes, in order to design lighter yet better bikes. The ride database helped Trek Engineer Sagan and the Project Orion team compute "fluid dynamics," to understand what happens to the "dirty air" that flows past and through Lance Armstrong's always chopping legs as well as surrounding tubes, cranks and pedals. The data also allows the team to perform "finite element analysis,'' showing them the exact locations of stress on the carbon fibers that make up the frame—and where layers of carbon fiber can be reduced.

3-D Modeling

The Orion team, which included composite engineers and carbon fiber frame pioneer Jim Colgrove, produced a breakthrough in the company's drive to develop ever-thinner sheets of carbon fibers. In 2005, layers of Optimum Compaction Low Void (OCLV) carbon weighed just 55 grams, or a little less than 2 ounces, per square meter.  Carbon weight refers to the weight of carbon fiber, per square meter, in the material used to make the frame's tubes & lugs. A lower number means the frame can be built lighter with the same weight.  That's only slightly more than three times the weight of the plastic that wraps a deck of playing cards (15 grams per square meter).  This is the lightest carbon that you can currently build a frame.  The Madone SSLX is about a third of the weight of the production model Trek bike that Armstrong used in his initial Tour victory in 1999. In that bike, the carbon weighed 150 grams per square meter.

THE CARBON FIBRE PROCESS                                                                 

Carbonfibre is a non isotrope material. That means that all fibres have to point the same direction as the forcelines through the material. If this is not the case, there will be an opposite effect. To be understandable, wood is also not isotrope, aluminium and copper are for sure.
You can also notice on the table that carbon fibres are 3 times stronger and more than 4 times lighter than steel!  Carbon fibre has its advantages and disadvantages for bicycle construction. Standardized sizes are required, since it's expensive to make the molds. As a consequence, it's more of a challenge to build a custom-made frame. Sure that can be done with carbon fibre, but then the frame has to be glued and that's much different than a monocoque frame.

Production

Most commonly, carbon fibres are produced from the polymere PAN. After an improved Sohio process which involves an amonoxidation reaction between propene and ammonia, the result is acrylonitrile, which transforms into polyacrylonitrile after polymerisation.

Once this polymer has been produced, the manufacture of carbon fibre can proceed. The first step of the process is to stretch the polymer so that it is parallel to what will eventually become the axis of the fibre. Once this has been done, the polymer is oxidised at 200-300°C in air, which removes hydrogen and adds oxygen to the molecule and forms the basis of the hexagonal structure seen above.  The white chain polymer had now become a black ring polymer, that has to be purified by carbonisation. This involves heating the polymer to up to 2500°C in a nitrogen rich environment, which expels impurities until the polymer contains 92 - 100% carbon, depending on the quality required for the fibre. The final stages in the production of carbon fibre involve weaving the fibres into sheets and embedding them in an epoxy resin, also called sizing. The result are sheets of black carbon fibre.  A pre-impregnated epoxy resin and an aluminium honeycomb layer, is sandwiched between two layers of carbon fibre. 
 

The first stage of the manufacturing process is to build a solid (computercut) pattern, from which a mold is produced. The molds are constructed by laying a total of 10 layers of pre-impregnated (with resin) carbon fibre on top of each pattern to produce the mold. The production of the mold takes place in several stages, involving vacuum treatments, debulking and heating processes. The mold then has to be thoughroughly cleaned and prepared for use.

The next phase is the actual fabrication, made from sheets of pre-cut, pre-impregnated carbon fibre, which are carefully laid inside the molds. Tooling refers to making the molds and parts used to produce the OCLV Carbon frames. The tooling is based on digital prototypes and all of the TTX tooling was created in-house at Trek’s Advanced Concept Group prototype shop in downtown Waterloo. Both engineers and programmers use robotic CNC machines that carve the molds out of billet aluminum. Mold making is the expensive part of the process.  It is thereby vital orientate the carbon fibre sheets in pre determined directions in order to achieve the desired strength. A total of 5 layers of carbon fibre are laid, forming the outer skin of the chassis (to achieve a final, cured thickness of 1mm, a total of 3-4 layers of carbon fibre must be laid down)

The next stage of the process is to cure the carbon fibre in an autoclave. This exposes the carbon fibre to a number of temperature / pressure cycles according to the specific requirements of the materials and components being processed. During this treatment, the resin impregnated in the carbon fibre flows into the surrounding fibres and is activated, thereby curing the carbon fibre. Once the outer skin has been cured and cooled down, a honeyomb layer of aluminium is fixed onto the outer skin by a sheet of resin to ensure the materials stick stongly together. The chassis panel then returns to the autoclave for curing. After having cooled down again, one more layer, consisting of a number of pre-impregnated carbon fibre sheet is placed on top the existing skin, and again treated in the autoclave for a final time.

Trek invested millions of dollars and 15 years in perfecting their patented OCLV carbon fibre technology process. If there are any air bubbles in the laminate, these create voids (air pockets within the structure) or weak spots. According to Trek, the approved aircraft industry spec for carbon laminate is under 2% voids. Trek OCLV frames average fewer than 1% voids.

Bike Design

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