JEC Group have brought together the international community of composites leaders and executives in our Composites Circle as an unique networking opportunity to meet with both peers and future partners.
Professor and Architect Mark Goulthorpe, of the MIT Department of Architecture, confirmed as guest keynote speaker for the Future of Composites in Construction.
Founded in 1987 by Roland Cattin, TIME engineers, manufactures, and distributes highly technical bicycle products. Its illustrious history began with the introduction of the very first automatic pedal system designed to accommodate the biomechanical constraints of the rider – a revolution in pedal design.
In 1988, TIME won its first two Tours de France with Pedro Delgado and Jeannie Longo. Since then, the company has enjoyed one competition victory after the next. With more than 10 victories to its name, TIME has been by far and away the most successful automatic pedal in the most prestigious of cycle races: the Tour de France. Since the beginning, TIME’s mission statement has been focused: innovate, in order to deliver high-end, technical products. A strong commitment to competition cycling associated with a strategy founded on innovation has allowed the company to build a prestigious brand that is recognised internationally.
From road-bike and mountain bike pedals to shoes, TIME has steadily developed a complete line of innovative products for the world of cycling. In 1993, the company began a promising campaign of diversification into the field of carbon composite frames, using its exclusive Resin Transfer Moulding (RTM) technology. In 2007, two major sectors of activity were added to its product offering: wheels and assembled bicycles.
TIME products are targeted at two distinct markets, with their own specific developments: the OEM market (selling components such as pedals or carbon forks to cycle manufacturers); and the aftermarket (selling components – shoes, pedals, carbon frames, wheels and assembled bikes – to bicycle shops).
TIME is in the process of consolidating its activity by bringing together the R&D department, the test centre, the finishing operations for carbon products, the braiding, lay-up and moulding activities, and the manufacturing of TIME wheels in its new Isle d’Abeau production plant. The company also operates an industrial plant in Slovakia that manufactures certain primary carbon parts.
JEC Composites Magazine: In the world of cycling, how do you generally distinguish between the different types of discipline (road cycling, racing, leisure, mountain biking, and so on)?
JEAN MARC GUEUGNEAUD : Cycle sport is, effectively, divided into various disciplines.
Road cycling is one of the most familiar, involving large numbers of amateur cyclists who cover long distances in training, either with a view to preparing for amateur races, mass-participation cycling events, or simply as a way of keeping in shape. The top competitors may turn professional, participating with their teams in international competitions (the national tours, the classics, etc.). Professional competition is the shop window for bike and accessory manufacturers, offering them a showcase for promoting and demonstrating the quality of their products.
A more recent activity, but one which is just as popular, off-road biking is subdivided into various disciplines such as cross-country, free-ride, downhill, endurance, etc. Off-road biking involves a larger population than road cycling because certain of its disciplines are more orientated towards leisure. Ski resorts, for example, are also trying to popularize downhill mountain biking as a way of attracting clientele outside of the winter season.
There are also more marginal disciplines such as track cycling, BMX, cyclocross and so on. Each discipline uses a specific type of machine, whose specs are dictated by technical, regulatory or economic criteria.
JCM: What are the different parts of a bike: frame, stem, wheels, drivetrain, brakes, etc.?
J.M.G.: Even if the bikes used for the various disciplines differ considerably, the same types of part are found on most of the products.
The frame, the central element, is the chassis of the bike. It is of key importance, since its design and construction will determine the performance, road-holding, comfort and position of the cyclist. Its choice is therefore of the utmost importance. The fork is now an integral part of the frame design, particularly since the advent of integrated stems.
The wheels are also one of the basic components that determine how the bike behaves. Unlike the frame, however, they are interchangeable and an experienced cyclist often possesses several sets (training, competition, hillclimbing, etc.).
Next, there is the drivetrain, manufactured by the top equipment manufacturers. The drivetrain kit is composed of the gear system, itself comprising the derailleurs, control levers (brakes + derailleur gears), chain and sprockets. Also included in the drivetrain are the pedals, brakes and, possibly, automatic pedals. These items may be switched for more exotic, "bought-in" components. Each equipment manufacturer proposes different types of drivetrain according to the range of bike to be equipped.
Finally, there are the peripheral components to round off the assembly. The handlebar assembly, consisting of handlebar and head tube, comes in various sizes or lengths in order to enable cyclists to adjust their position according to their frame or their morphology.
The seat post allows the saddle height to be adjusted. This is increasingly supplied with the frame since the advent of integrated seat posts (TIME innovation with the translink system). The saddle is an important factor when it comes to the comfort of the cyclist, and the user is often attached to a particular brand. Automatic pedals feature in most cycling disciplines, and each system has its own specific target audience.
JCM: Who makes what? Who are the world's "top manufacturers"?
J.M.G.: The cycle market is very piecemeal, with many manufacturers sharing the global market. The segment is divided into several sectors:
JCM: Why is there an increasing use of composites? What parts will never be made of composites?
J.M.G.: The first composite frames appeared in the 1980s. These consisted of simple tubular elements bonded to light alloy couplings. Despite its intrinsic qualities, the material had difficulty imposing itself. Following an initial carbon wave between 1985 and 1991, on the back of the success of TVT (5 victories in the Tour de France), the market consolidated around aluminium on account of certain technical difficulties (adhesive bonding), but also due to the failure of mainstream manufacturers to propose the material since they did not have access to the technology.
As from 1995, certain mainstream manufacturers, taking their cue from composite specialists (in particular, TIME), began to propose carbon forks on their metal bikes (Merlin, Cannondale, etc.). A safety component subject to extreme stress, the composite fork offered significant weight savings and improved robustness. The generalisation of composite forks on all mid/high-end bikes turned the material into a credible option in the eyes of consumers. With the massive onset of subcontracting possibilities, particularly in Asia, the top manufacturers went off to "do business" with these subcontractors. Today, all mid/high-end bicycles are assembled on a carbon frame. The qualities of the material – lightness, rigidity, fatigue resistance and enhanced performance – have led to the majority of components today being made out of composites, in particular handlebars, stems, certain derailleur components, saddles and even entire wheels. Only the drivetrain elements – chain, sprockets, chainrings – seem to be exempt from this development on account of the specific constraints involved (high pressure, abrasion, small dimensions, etc.). By way of example, a carbon frame of the 1990s weighed 1500 g with tube walls 2.5 mm in thickness, whereas its modern equivalent weighs 1000 g for wall thicknesses close to 1 millimetre.
JCM: The trend for the "one-piece" offers many advantages both with respect to the product itself and in terms of production.
J.M.G.: Logically, the first "carbon" frames were produced on the basis of tubular elements assembled by means of bonding to light alloy couplings, offering performance enhancements that were already significant when compared to metal frames. The first frames with carbon couplings appeared several years later, alongside the first so-called "monocoque" frames. At that time, the advantage was with bonded assemblies which, thanks to greater mastery of the subassembly manufacturing process, offered lighter, better performing products, particularly inasmuch as bonded assemblies – the Achilles heel of the first carbon frames – had been perfectly mastered.
Today the situation is somewhat different. Improved manufacturing of complex structures now makes it possible to benefit from all the advantages of a "monocoque" construction, so dispensing with the bonding assembly times, certain reworking operations and complex component management. Monocoque construction also makes it possible to "free up" the bonding zones, subject to extreme technical constraints, for improved design and optimization of each frame size. This is therefore of dual interest: both industrial, through simplification of the industrial process, and technical, through improved quality of design and optimization.
JCM: TIME has chosen the braid + RTM technique rather than the prepreg technique (fabric + UD). Why this choice?
J.M.G.: TIME chose to use braid + RTM technology because it is perfectly suited to the manufacturing of small diameter tubular structures, which applies perfectly to the bicycle frame. In making our choice we also took into account the notions of safety, important in the case of the competition bike subject to the risk of falls in the group of riders, but also in relation to road traffic risks, particularly during training, or stresses linked to bicycle transportation (in car boots, by air, etc.). Braided structures offer the guarantee of fibre continuity right to the outer surface of the part, while the mechanical interlinking of the fibres ensures good resistance to impact and cracking, particularly in the vicinity of drill holes required for attaching accessories (bottle holder, cable stops, etc.). They also offer perfect control over the mechanical characteristics thanks to optimized fibre orientations (from 15° to 65°), with the directional laying of exotic fibres making it possible to generate nuanced behaviour that is hard to equal with other technologies. TIME also chose to mould its composite parts by RTM using fusible cores. This technology guarantees excellent thickness control, along with the perfect cohesion of the different layers. (image de préforme) This also makes it possible to generate complex internal forms such as the Stiff reinforcement (image) found in the steerer tubes, or to position reinforcement zones with ease. The matrix is a high-performance epoxy resin with a Tg of 125°C.
The combination of a braided structure and RTM moulding also ensures excellent manufacturing reproducibility by simplifying the layup process (dry fabric that is easy to handle and non-irritant for operators).
JCM: Is it possible to quantify the amount of carbon used worldwide in bicycle production, based on an average weight per bike and the number of bikes manufactured today?
J.M.G.: Worldwide production accounts for around 100 million bikes, all types included. If you consider that sports bikes represent around ± 5% of the total volume, i.e. 5 million bikes, the population of carbon bikes should represent 30% of this total, in other words approximately 1.5 million units.
With the average weight of a racing bike at approximately 7.5 kg, and the carbon content representing an average of 2 kg, the "bike" business taken as a whole represents an annual consumption of 3,000 metric tons of carbon fibre.
Here are few examples and update of these two techniques which can be seen in many application sectors now.