Carbon

We have been developing and producing bike frames for nearly 70 years. In 2003 we threw ourselves into carbon with the famous 0.9C, the first monocoque carbon road frame. Thanks to the revolutionary concept at this time, this frame weighing just 900g in size 52 shone on the roads of the Tour de France.

For over 10 years, our engineers have closely collaborated with professional riders and the very best carbon frame makers to develop and improve our carbon frame construction, to make them lighter, stronger and better performing.

We have two main criterias: a fabrication that respects the highest standards of quality and a choice of types of fibres that perfectly attain the qualities required of each bike.

 

Fabrication

The fabrication of carbon frames requires specialist knowledge to obtain frames with a perfect structure and exceptional finish.

One of the elements that enables us to achieve such exacting demands is the care we place into developing our tools. When our engineers finish the 3D model of a new frame, the fabrication of the mould is launched. This is the biggest investment in any carbon project. Several prototypes are built in order to finalise the mould.

The quality of the mould determines the final quality of the finished bike. Accordingly, special attention is paid to it. The layup of different fibres is then entirely done by hand. Each tube has its own structure that must be exactly adhered to so we have a very precise process for creating our frames: 

  • For the majority of our bikes, the front triangle, made up of the top tube, the down tube, the head tube and the seat tube is created as one, therefore it is « monocoque ».

  • To make the front triangle, the sheets of unidirectional carbon fibre are first cut into the form of the different zones of the frame.

  • These resin impregnanted sheets (called « pré-impregnated ») are applied onto mandrels giving the internal form of each tube. This stage is crucial because it determines the final structure, adjusting the number of layers of carbon and the orientation of the fibres: the numerous layers of pre-impregnated fibres will be applied on the zones where the greatest stiffness is needed (for example the bottom bracket). Fewer layers are needed in the areas that require more flex (for example the seat tube). These sheets are also applied with a very precise interlacing pattern to optimise the resistance qualities of each tube.

  • The front triangle is then placed in the mould, which is squeezed with the aid of a press.

  • Bladders, inflated at high pressure inside the frame, give the internal form to each tube.

  • The whole frame is then heated to solidify the resin.

  • After taking it out of the frame and cooling, the bladders and mandrels are extracted.

  • The same process is followed for the rear triangle.

  • Once the different parts of the frame have been produced, they are assembled. This assemblage is carried out on a jig in order to obtain a frame that conforms exactly to the predefined geometry.

  • The full frame is the heated again to harden the different joints.

  • The frame is then polished to reach a completely smooth finish. It is then ready to be painted and varnished.

     

Throughout this process, the frame and the different parts are submitted for tests to control the quality of production (the quality of surface, structure, fibre cohesion, the resin, joints, etc.), and the geometry.

Before launching the production of a series , the first prototypes are tested, dissected and analysed in every detail by our R&D department, in Dijon. Following this, other prototypes are subjected to very strict tests for fatigue, resistance and stiffness.

Finally, numerous tests are carried out by Lapierre’s professional riders : l’équipe cycliste FDJ.fr for road bikes, and Team Lapierre Gravity Republic and Nicolas Vouilloz, amongst others, for mountain bikes. Their exacting eye pushes our frames into their last small changes, and their unique feedback enables us to check the real performance of each new carbon product.  

After this series of tests, some modifications can still be done to the assembly of fibres, to the mould, or to the finish in order to achieve the ideal bike.

 

Types of fibres

The choice of fibres is the second key to success of any carbon project. Each type of fibre has very specific characteristics of stiffness and resistance, and therefore a precise type of usage.  To choose the best fibres we work with the best specialist producers of high end carbon.

Between stiffness and resistance

The types of fibres are characterised by two criteria: stiffness (Young module) and resistance.

The Young module is an indication of the stiffness of a material. 

► The higher the value, the stiffer the fibre.

Young module values are expressed in GPa (Giga-Pascal) or in tonne/mm², usually shortened to « tonne » by the industry.

► Resistances denote the level at which a material will break.

The higher the value of resistance, the more the fibre can cope with big shocks.   Our engineers work tirelessly to determine the correct mix of different types of fibres to obtain the correct balance between stiffness and resistance.

Lapierre's fibres

To construct our frames, we use 4 types of fibres :

  • 24 tonne module fibres

  • 30 tonne module fibres

  • 40 tonne module fibres

  • 46 tonne module fibres

We can also class fibres by the value of their resistance : High Resistance (HR), Intermediate Module (IM), High Module (HM) and Very High Module (VHM).

Below you’ll find the details of the different fibres we use, their strong points and their role :

 

Which fibres for which bike ?

Each Lapierre frame is constructed using several types of fibres that have been carefully studied.

  • AIRCODE : aerodynamic race frame

24t and 30t fibres for resistance and  40t fibres for stiffness.

  • XELIUS EFI : road race frame

24t and 30t fibres for resistance and  40t and 46t fibres for extreme stiffness

  • PULSIUM : endurance race frame

24t et 30t fibres for resistance against shocks and 40t fibres for exceptional stiffness

  • SENSIUM : endurance

24t et 30t fibres for resistance against shocks and vibration absorption

  • SHAPER 900 & 700 : fitness

24t & 30t for vibration absorption and comfort

  • AEROSTORM : time trial and triathlons

30t & 40t fibres for the best compromise between stiffness and fatigue resistance.

  • CX Carbon : cyclocross

24t fibres for optimal vibration and shock absorption

 

Power Box

Proven over several seasons of usage on the Xelius EFI, Power Box technology is now standard on our competition bikes. For 2015, Power Box has been integrated into the two new models, used by team FDJ.fr: Aircode and Pulsium.

Despite their different types of usage, aerodynamics for Aircode and endurance for Pulsium, Power Box technology is put into use on both bikes for the same reason: to gain optimal rigidity on the head tube, bottom bracket and rear wheel axle.  This enables us to ensure the transmission of power created by pedaling. An indispensable criteria for bikes used on the UCI World Tour.

The principle of Power Box technology rests on two elements : oversized tubes and maximum fibre lengths.

Firstly, the head tube, down tube, bottom bracket and the chain stays are created with noticeably wider tubes than those of the other zones.  This zone is exclusively reserved for power transmission and therefore needs to be made as rigid as possible.  

Next, we have maximised the lengths of the fibres used between the head tube and the bottom bracket. These fibres, in unidirectional carbon , should be parallel and the maximum length possible for the best power transfer. 

In bringing together these two elements, all your power is transmitted directly to the rear wheel.

 

You won't lose a single watt!