In love with carbon.
The emotional brain, its rational and scientific part. The result of the most careful and precise research studies on materials and the latest engineering findings.
Only those who deeply love carbon, know even its tiniest fibres. And above all, he/she knows that a real monocoque frame may only be considered such if made in a single piece. Without connections and glue between the tubes.
This will be the frame of your next bycicle.
Swi One is the first and only real monocoque frame on the market, built according to UFS™ technology (Unishell Frame System).
This is the only principle we know. That of excellence.
Think of an empty egg shell: completely sealed and smooth, without any type of interruption. Unishell Frame is a load-bearing frame model that is registered and patented by Swisstech Engineering and is based on the integrity (front triangle and rear axle fitting secured by the housings for the aluminium dropout attachments) of the frame as a monocoque, i.e. conceived as a single mould to increase the strength and the overall structural rigidity of both the transversal and longitudinal torsion.
The absence of interruptions in the carbon fibres means the frame can absorb and homogenously release, over its entire length, the passive energy caused by ground stress while racing, thus transforming the power delivered by the athlete into maximum propulsion.
Compared to the frame commonly known as “monocoque” which is used in different variants for many racing bike models, the integrated load-bearing frame guarantees a lower overall weight, greater safety in case of impact against obstacles and unevenness in the ground (deformation is more progressive), high resistance and controlled structural rigidity, giving enhanced reactivity during ciclying.
The key to increasing the structural performance of the frame is the rational use of the many features of the carbon fibre in the different parts of the frame; such features are mainly based on the weight and number of laminate layers, on their direction and thickness.
All SWI frames are made exclusively with UD (uni-directional) fibres. Unlike common carbon fibre products that are made of interwoven fibres (with the classic cross-ply appearance), UD carbon is literally a continuous piece of carbon with filaments placed in a single direction.
In some parts, our frames can have even 28 very thin layers of UD carbon laminate, each made of different pieces placed side by side, as in the manufacturing of a suit. A frame can be made of up to a total of almost 350 single carbon pieces that are positioned in the mould before the heating and moulding phases.
These pieces of material, which can be very small or large, are arranged in layers at different angles in order to achieve several types of performance: axial and torsional rigidity with controlled yielding or maximum resistance.
The overlapping of layers is extremely important for the final result. This is a key factor for the construction of a “racing” carbon fibre frame.
These carbon fibre layers can be seen on the surface of our unpainted frames through the transparent finish. What might seem to be a fault is actually a quality which we are very proud of, as it allows us to show special construction details and demonstrate not only the quality of the hand work on the frame, but also the high quality of the same frame as it’s taken out of the mould.
In order to make such a light and technologically advanced monocoque frame, we have had to use such complex fibre composites that it would be impossible to achieve the same perfection without the use of sophisticated weaving machines.
Each composite preform, which has different features based on its direction and weight, is laid inside the mould exactly as set out during the project phase and following software calculated values. Only in this way it is possible to reach the frame production standard required by the minimum safety requirements provided for by the ISO 4210-6:2014 (International Organization for Standardization).
The North Thin Ply Technology™ of Lausanne (Switzerland) is the official and sole supplier of all the carbon fibre laminate used for the production of our frames.
TPT™ Thin Ply TechnologyTPT stands for Thin Ply Technology™, i.e. the technology of thin plies.
In other words and more simply, the thinner the laminate plies (final thickness being equal) the better the mechanical properties. Therefore, with the same mechanical properties, we have less thickness and lighter weight.
Based on this principle, a new technology has been developed and has led to carbon filaments being increasingly thinner (from 11 to 5 microns); it is better to have numerous strands rather than a single one, of the same weight, producing increasingly thinner and lighter woven materials.
NTPT does not use the conventional laminate used for the construction of most frames on the market. Based on experience in the production of carbon fibre sails for the America’s Cup, it buys the filaments and personally weaves them using its own patented and secret technology.
As far as we have been able to find out, the process involves the use of special weaving machines to obtain some reels of unidirectional fabric impregnated with epoxy resin which can reach a few hundredths of a millimiter in thickness and a weight of 15 grams per square metre.
The pre-preg fabric reels are then transferred to a special machine that, working on three axles, places the various laminate layers over each other facing in different directions according to application requirements.
A single pre-preg multilayer fabric is thereby obtained. In our case we are talking about 3 or 4 layers with an orientation for example of 0°/+45°/-45°/90°.
Depending on the type of performance required and on the different strength loads supported by the different parts of the frame, we apply the plies of this multi-layered and multidirectional laminate inside the mould: the final result will be a frame made of 28 layers of unidirectional carbon laminate, arranged at 0°, +-30°,+-45°, +-60° and 90°.
It’s obviously more difficult to handle thinner and lighter fabrics and it takes much longer to lay many laminate layers, but the advantages are clear, which is why we have decided to move in this direction despite the cost of the laminate which is 10 times higher than the conventional one used by most makers of frames for racing bicycles.
This revolutionary technology to make fabrics is a patent of the North Thin Ply Technology™ of Cossonay (Switzerland) and the result of years of experience in the production of carbon sails for the America’s Cup boats.
Engineering worksMost people think of bycicles as simple machines: actually, the designing of a frame and the study of loads to be supported are very difficult and complex to analyze and simulate due to the huge amount of possible variables.
The process starts with the modeling of the surfaces that is carried out using the Rhinoceros™ software. After having selected the external shape of the frame, it is also possible to simulate the assembly of the bottom bracket and the space taken up by the pedals and chainring, the positioning of conventional or disk brakes, the passage of chains through the chainstays and sprocket set, the attachments of derailleurs and wheels, the routing of cables inside the tubing, the seat post and the fork, as well as all accessories, such as the battery of the electronic gearbox and the water bottle cage.
It is crucial that all these simulations are carried out with perfect pinpoint accuracy and therefore, in order to validate the drawings and to check that everything has been perfectly designed, a 1:1 scale polycarbonate prototype has been made by rapid prototyping from a 3D printer.
Finite Element AnalysisAfter approval, the 3D design will be processed to carry out structural analyses using the Finite Element Analysis (FEA). This software divides the 3D frame design into many meshes or simple geometries, known as finite elements, to which a mathematical model is applied. In our case, the behaviour of the frame is simulated according to different loads and torsions in different cycling conditions.
After evaluating the results and making the appropriate modifications, we have been able to set the minimum safety requirements and optimize the use of material without affecting the strength, rigidity and light weight.
Thanks to the one-piece construction of the frame, the loads applied are homogenously supported by the whole structure, thus preventing the formation of stress areas or weak zones.
Finally, we determined the best shape for the frame structure, the sections and the sizes of the tubing.
Using the final frame design and the calculation results, we entered the data again in the Rhinoceros™ software to create a detailed mould model.
Swisstech has developed an innovative procedure for designing its own frame moulds which is called MMS™ (Modular Moulding System) - a complex and sophisticated modular mould that makes it possible to produce our frames in a single solution.
Being totally moulded in one piece and made of 28 layers of very thin carbon fibre laminate, the One frame boasts excellent mechanical features.
The carbon laminate, which is made of multiple layers of fibre and resin, is cut by the plotter in line with the preforms established during the design phase which are meticulously laid side by side or over each other inside the mould in the exact positions (layup) specified by the software, in multiple layers in different directions and of different thicknesses depending on the load lines; the advantage is that thanks to these multiple thin layers, equal in thickness, the laminate can guarantee more resistance and, with equal resistance, allow for reduced thickness, thus being lighter.
The inner and outer walls of the frame inside the mould are placed in a vacuum by a combination system consisting of a silicon bag and latex membranes to completely remove any air and therefore prevent the formation of bubbles inside the structure of the carbon fibre.
The mould is then placed in the autoclave oven at a pressure of 6 bars at a temperature of 120°C.
The combination of the internal vacuum with the external high pressure compacts the structure of the fibre that appears perfectly homogeneous and smooth even inside the tubes.
Technical detailsThe weight of the SWI One frame ranges from 700 to 800 grams, depending on the size. We could have gone even below this treshold, but we preferred to be cautious and keep within these limits, pending further UCI decisions on new standards for the weight of bicycles.
The top tube, the tapered head tube, the down tube, the seat tube, the 86.5 mm PressFit asymmetric bottom bracket and all the rear axle fitting which consists of the chainstays and seatstays closed on the top by the attachments of the wheel hub have been designed to be moulded and shaped in one piece.
The attachments of the rear wheel hub are made of full multi-layers in carbon fibre moulded with the frame, while the interchangeable dropouts of Ergal 7075 solid aluminium are made by 5-axle CNC machines and are fitted and fixed in place by two screws. The front fork weighs less than 350 grams and is built separately using the same UD carbon fibre laminate; it is attached to the head tube by means of a bearing group.
The internal cable routing system has been designed and computer-simulated so that there are no obstacles to the sliding of steel cables.
The electric cable of the gearbox and the tubes of the hydraulic disk braking system, also run inside the frame.
In the model with hydraulic disk brakes, the frame has been designed for the new brakes with standard “Flat Mount”, which are currently produced only by Shimano and Sram. Before the final paint finish, the frame is checked by special high-precision measuring instruments to verify that all dimensions are the same as those set out in the original design, to the nearest millimeter.
Our frames come out from the mould pretty much already polished and do not need any filling, just a light sanding to remove the inevitable partition lines of the mould.
Many makers prefer to paint their frames to cover the manufacturing imperfections that need to be filled, smoothed and then painted (as it happens in car body shops).
We use two different types of paint. The first is used on the “racing” models and is a simple transparent protective varnish which is very light and weighs about 50 grams.
The seconf type of paint is aesthetically more “elegant” and is applied in several coats and weighs about 150 grams.
TestsIn order to validate the engineering design, our frame prototypes undergo a vast testing regime, initially in the laboratory, certified by authorized external laboratories.
The load tests carried out were at least 10% over the minimum requirements of the ISO 4210-6:2014 standard (International Organization for Standardization) both in the force applied to in the crash test and in the number of test cycles for fatigue. Considering that laboratory tests may not reflect reality, we equipped some SWI One prototypes with sensors to carry out the dynamic analysis of structural stress during different cycling conditions with a professional cyclist.
The torque/strain sensors showed that giving under loads is distributed in certain points of the frame in a slightly different way from the simulations carried out. Cycling style greatly affects the load, for example in carving type turns, on a fast downhill or a vigorous stand up pedal that puts severe stress on the whole system. Strain data have forced us to structural changes to add more strength and rigidity in some parts, whilst keeping the total use of material low so as not to compromise the weight. For example, the bottom bracket, that puts a heavy load on the rear frame, has been changed to increase the resitance and rigidity of the whole system.
Finally, we wanted to compare our frame with some of those on the market that have been manufactured with different technologies. In particular, we compared three different technologies for manufacturing carbon fibre frames: the wrapped frames made of independent tubes glued toghether; frames made with independent tubes joined together by means of connector shells and glued; conventional monocoque frames with only the front triangle monocoque and the rear axle fitting glued.
Laboratory and road tests have highlighted the superior structural and mechanical properties of our integrated monocoque frame as it showed better rigidity and longitudinal and torsional elasticity that give greater comfort and improved pedaling efficiency both seated and out of the saddle.
GeometryFirst of all, we defined the standards of proportions to apply to the geometries of the frame by computer processing the data entered into the databases created thanks to hundreds of biomechanical measurements carried out on cyclists in the laboratory, thus obtaining values representing the most people possible per each size.
Thanks to the data obtained, we were able to establish 12 basic sizes that have only 1 cm. difference between each other. In this way, we have grouped together nearly all possible human body conformations; it is also possible to make custom tailored frames on request for people with special measurements.
The Swi One frame is manufactured in 12 sizes from 50 up to 61 cm. This gap of only a centimetre between each size and such a large range of sizes allow us to offer our customers a better chance of finding their right size. The manufacturing time of the standard frame is about 60 days.
On request, a “Custom Made” bike can be manufactured, based on the measurements ordered by the client. An exclusive monocoque mould will be made, and delivery time is about 90 days.
|Wheel Size||700 c||700 c||700 c||700 c||700 c||700 c||700 c||700 c||700 c||700 c||700 c||700 c|
|Head Tube Angle||70°||70,5°||71,1°||71,8°||72,5°||73,2°||73,5°||73,5°||73,5°||73,5°||73,5°||73,5°|
|Head Tube Lenght||106||116||128||139||150||160||173||186||198||211||224||237|
|Seat Tube Angle||73°||73°||73°||73°||73°||73°||73°||73°||73°||73°||73°||73°|
- Everything we designed for Swi One has been realized. We are confident that nothing was left to chance and are aware of having worked according to the highest state-of-the-art quality standards.
- In order to achieve all this, we have been forced to make “anti-commercial” choices, meaning that we never asked ourselves “how much is it?”, so as not to set limits to the project.
- We have applied the very best in research for the development of composite materials, of engineering and electronics, of technology during the production and design processes, and we have integrated them with all the other components of the mobility system to manufacture an innovative and unique type of product.
- Swi One is an extremely advanced racing machine produced in a limited number as it is not industrially manufactured.
- The frame has been developed and entirely made in Switzerland using very expensive materials and therefore its price cannot be compared to that of the frames built in Asian countries.
- Swi One is produced in 12 sizes from 50 to 61 cm.
- In the “Custom Fit” model, the frame is built by means of a mould that can be used exclusively by a single customer and therefore its price is higher than the standard one.
- A product targeted to professional cycling teams and to demanding cyclists looking for a “Made in Switzerland” exclusive and prestigious product of the highest quality.
- Prices of finished bicycles vary depending on the components. It will soon be possible to calculate the price on this website using our configurator. Meanwhile, please do not hesitate to contact us for any price details and information.
- The frame comes with a lifetime warranty against all manufacturing defects and is compliant with the safety requirements of ISO 4210-6:2014 standard and all geometry restrictions provided by the Union Cycliste Internationale (UCI).