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Look 795 Blade RS carbon frame

News International-French

1 Oct 2019

There was a time when aero road bikes only focused on aerodynamics, but this time has passed and the 795 Blade RS is Look’s iteration of a bike that fulfills all road cyclists dreams.

The 795 Blade RS cuts through the air, provides unmatched stiffness to weight ratio in the aero bikes category and it maintains traction where other bikes fail thanks to an innovative rear triangle design and large tire clearance. In summary, the 795 Blade RS is packed with so many features that assure it is the fastest, smoothest and most versatile bike Look has ever made.

The design
A fast bike is a bike capable of transfering the highest percentage of the cyclist’s power to the road, creating forward motion.
Their new 3S Technology is all about rear wheel traction. By creating longer and curved seatstays, having no bridge between them (on both rim brakes and disc brakes version) and optimizing the carbon lay-up to allow some vertical movement while maintaining lateral stiffness of the rear triangle they give the cyclist not only traction but also comfort.
One of the benefit of bringing traction and comfort in the rear triangle is that the bike does not rely on a flexible seat post, thus improving pedaling efficiency once again!

3S DESIGN:

3S Design: Optimize traction transfer 100% of the power to the road (©Lookcycle.com)

 

Vincent Holterboch, Head of R&D and Product Marketing departements Look Cycle answer to JEC Composites Magazine:

Vincent Holterboch,  Head of R&D and Product Marketing departements Look Cycle

What are the specifications for the design of a bicycle that incorporates composite materials?
"A frame is above all a mechanical structural part. We convert the chosen experience-based data for the bicycle into physical values (degrees of stiffness, weights, geometries, aerodynamic profile), and then into building the product. You have to compromise: the speeds, state of the roads, cyclist weight, and type of use are all variable. The frame is an inert entity. At least, that is the current requirement of the Union Cycliste Internationale (UCI). We add additional style constraints, because the frame should be attractive (lines and paint), as well as immediately identifiable on a podium. The one-piece carbon shell has enabled a lot more flexibility in this approach than welded or formed metal frames."

Aerodynamism
Look was one of the first bike manufacturer to use Computational Fluid Dynamics software to optimize new bikes design. Now it seems a common thing, but you need a lot of experience to understand all CFD can do. Only an expert eyes can talk with the results of calculation. Look collaborates with one of the best Formula 1 Aerodynamicist in the World.


AERODYNAMISM:

Aerodynamism: CFD deveopment (©Lookcycle.com)

How its carbon fibre frame is made?
Let's take a look around the Look Cycle headquarters in France and their production facility in Tunisia, to get a thorough insight into the manufacture of carbon fiber road bikes.

How Are Carbon Fibre Bikes Made? | LOOK Cycle Factory Tour

How are carbon fibre bikes made? | Look Cycle factory tour (©Global Cycling Network)

Step1: Making Carbon Fiber
The new 795 Blade RS is made with a mix of different carbon fibres. They combine these fibres to optimize the different performance parameters.

  • HM : High Modulus: High-end fibers. Their stiffness rating is very high, about double that of HR. These fibers are used wisely because they are more brittle. HM fibers allow added stiffness with the lowest weight penalty.
  • IM : Intermediate Modulus: They have good resistance and fall somewhere between HM and HR of which they are a good complement.
  • HR : High Resistance: High resistance fibers are less stiff in elongation but can resist deformations and impacts better, they are very useful in high stress areas and also in areas where controlled deformation is beneficial to the ride quality of the bike.

Making Carbon Fiber

Carbon prereg used for the Look 795 Blade RS carbon frame (©Global Cycling Network)

Step 2: Cutting out the carbon fiber
To make the 795 Blade RS carbon frame 405 individual carbon pieces are necessary. They are cutted either manually, or by a CNC machine.

Cutting

Carbon pieces cutted manually by operators and/or by CNC machines (©Global Cycling Network)

Step 3: Assembling
All the carbon pieces are laid up in a specific order according to a complicated 3D puzzle. It take advantage of the unidirectional carbon fiber properties with pieces laid in one direction, while other pieces are laid in the opposite direction. This create some reinforcements depending of the fiber orientation.They are all laid up around bladders or preforms.

Assembling around bladders or preforms

STIFFNESS – WEIGHT – TRACTION

Assembling around bladders or preforms (©Lookcycle.com)


Vincent Holterboch, Head of R&D and Product Marketing departements Look Cycle answer to JEC Composites Magazine:

Vincent Holterboch,  Head of R&D and Product Marketing departements Look Cycle

Can composite materials still help push the envelope of sports performance in the cycling world?

"The anisotropic properties of carbon structures still have a bright future. They provide the ideal performance exactly where it is needed, and nothing else. Other high-tech sectors like aerospace or F1 racing have made no mistake. We are testing additive manufacturing technologies with great interest, because they will certainly be a complement to current carbon/polymerized fabric technologies."


Step 4: Moulding
The global frame is mould throught a modulus monoque construction process. That mean that you have large parts of the frame like the single front triangle made separately to other part like the carbon fork, and then glued together before curing. The mold of the entire carbon frame with all parts glued is then place in a heating press which supplied 2 to 10 bars of pression incrementaly during 45 minutes, under 170 degree. Heating pressure is so applied outside of the frame, while bladders inflate on the inside of the frame compressing the carbon fiber lay up.

Press

Heating press which supplied 2 to 10 bars of pression incrementally during 45 minutes under 170 degree
(©Global Cycling Network)

Step 5: Debulking
The frame is left to cool for 15 minutes before it is removed from the mold. Then any exess of resin on the edge of the frame is trimmed off.

Debulking

Part is released after moulding and cooling (©Global Cycling Network)

Step 6: Curing the resin
The frame with its preforms go back in an oven to cure the resin, and then remove any remaining moisture or air gaps still in the frame.

Oven to cure the resin and remove any remaining moisture or air gaps

Oven to cure the resin and remove any remaining moisture or air gaps
(©Global Cycling Network)

Step 7: Surface preparation
Prefoms are removed during this step, and sanding surface treatment is issued.

Prefoms are removed manually by an operator

Prefoms are removed manually by an operator (©Global Cycling Network)

Vincent Holterboch, Head of R&D and Product Marketing departements Look Cycle answer to JEC Composites Magazine:

Vincent Holterboch,  Head of R&D and Product Marketing departements Look Cycle


What role can graphene play in cycling?

"It is more of an additive than a structural element in itself. Graphene improves the composite, its weight and its appearance even more. We are currently testing specimens to get an idea about this advanced technology, which is very costly in terms of materials. The range of very high-modulus carbons is still our main line of research."


Step 8: Machining process
Drilling and milling process are issued throught an automated robot arm.

 

Drilling and milling process

Drilling and milling process

Drilling and milling process (©Global Cycling Network)

Step 9: Joining front and rear triangle
The aim is to join the different finish parts together to make the complete frame with carbon fiber glue curing at 90 degrees for 1 hour in an oven. A special jig is used to fix all parts at the exact position, and an extra woven carbon fiber piece is used to reinforce the connection when necessary.

Joining front and rear triangle

Front and rear triangle are joined using a carbon fiber glue, and an extra woven carbon fiber piece is added
(©Global Cycling Network)

Step 10: Surface finishing
Sanding and polish preparation before painting.

Surface hand finishing

Surface hand finishing (©Global Cycling Network)
 

Vincent Holterboch, Head of R&D and Product Marketing departements Look Cycle andwer to JEC Composites Magazine:

Vincent Holterboch,  Head of R&D and Product Marketing departements Look Cycle

In your opinion, what characteristics will the Bicycle of the Year have in 2025?

"In 2025, a “perfect” series bicycle will no longer be the goal. Composite processes, design methods and available data for each cyclist will make it possible to create a bicycle for each customer and use.
Imagine a perfect symbiosis of your muscles, bones, handlebars and bottom-bracket axle, frame, wheel, and the road surface and gradient... we are working hard to find that optimum. There is no doubt that each ride on such a bicycle will bring a smile to the rider’s face. So in 2025, you’ll have to think “Bicycle Brand” of the Year, and Look Cycles with Corima wheels will have its place."

Step 11: Painting
The carbon surface has to be treated first and prepared for painting. Then once it is painted the decals are applied and a special varnish is sprayed.

Step 12: The final part
The Look 795 Blade RS carbon frame is ready to be mounted with your favorite equipment. Price is up to 8899€ with Shimano Dura Ace DI2, Proteam white glossy color on Lookcycle.com.


Painting and finish parts

Look 795 Blade RS carbon frame

Painting and finish parts

Look 795 Blade RS carbon frame (©Lookcycle.com)