As we believe that the value of a bicycle frame is mainly determined by: the quality of joints, properly selected tube cross sections, precise finishing of their surfaces and perfectly designed geometry, we go to every effort to combine all the factors mentioned above in EMKY frames. .
Aluminium is characterised by very high rigidity, which directly translates into steering precision, acceleration effectiveness and transferring the pedalling power onto the rear wheel. Riding an aluminium frame bike, particularly without a shock absorber, is not comfortable as the frame is too rigid to suppress micro-vibrations.
That is why many users of such frames need the vibration suppression which carbon fibre offers, however on the other hand they are concerned about lower resistance and relatively easy damage to which a bike frame made of carbon only is exposed during everyday use.
Using the properties of the most popular materials used to make bicycle frames, we decided to design and create a frame characterised by a compilation of the best features of these materials. The possibility to achieve particular mechanical parameters of the frame, such as shock-absorbing or resistance characteristics, directly depends on many factors, such as: the choice of an aluminium alloy, the type of fibres used, their orientation and the layout angle of layers, or resins, whose proper matching to the frame geometry guarantees that the whole structure has the most effective distribution of forces acting on it during use and that road unevenness is muffled while preserving proper rigidity at the same time.
In our designs, we combine:
- elements made of aluminium 7020, welded with TIG method and surface-treated manually, giving the structure the rigidity mentioned above and ensuring pedalling effectiveness and safety at the place of installation of accessories,
- carbon and wooden elements constituting a consistent and durable composite structure, designed and manually manufactured at EMKY Bikes, combining carbon fibres of proper weight and weave with seasoned and formed natural wood, which is heat treated to achieve its maximum mechanical parameters.
Due to this combination, EMKY frames ensure rigidity, resistance and reliability associated with aluminium frames, at the same time suppressing vibrations, which is so valued in carbon frames.
The use of selected and seasoned, diffuse-porous natural wood is a consequence of combining unique aesthetic values with exceptional mechanical properties. The uniqueness of an irreplaceable colour and device of every wood fragment used by us, grain irregularity and its natural texture make every frame, designed and manufactured by the EMKY team, one of a kind.
The wood used, thanks to its structure, possesses natural abilities to absorb the force of local impacts, which are extremely dangerous for frames made of uncovered carbon. That is why in our technological process we have used, as a protection barrier for fibre epoxy laminate, properly formed, laminated natural wood, covered with chemically hardened coatings, and thus perfectly protected against any external factors.
EMKY bicycles are built on EMKY composite frames whose construction nodes: a seat tube, bottom bracket, head tube, and chain and seat stays are welded manually with TIG method, subjected to proper thermal processing to eliminate generated stresses, and sanded manually to smooth the welds.
To produce our frames we only use aluminium alloy 7020-T6. Welding and other EMKY frame treatment operations are performed by highly-qualified specialists with modern equipment.
Aluminium 7020 is 700 series aluminium alloy whose main alloying element is zinc (4-7%), as well as magnesium (2-4%) and copper (0.5-1.7%). In European standards it is designated as EN AW-7020, its chemical determination is AlZn4,5Mg1. The alloy, subjected to proper welding treatment consistent with good welding practices, is used mainly in those welded structures which should be characterised by high resistance.
Compared to aluminium 6061-T6 (AlMg1SiCu), widely used to produce bicycle frames, grade 7020-T6 is characterised by higher fatigue limit and achieves significantly higher values of tensile strength.
Fatigue limit is the highest level of tension which can be applied for a specified number of cycles of material cyclic loading without causing its fatigue damage, and amounts to 130 MPa for aluminium 7020-T6 and 96 MPa for aluminium 6061-T6.
Tensile strength, defined as the maximum value of tensile stress which material can take during a short static tension, exceeding of which causes material damage, determines the value of 310 MPa for aluminium 7020-T6, while for alloy 6061-T6 it amounts to 270 MPa.
The tubes creating the main triangle are epoxy laminate of fibres of proper weight and weave and seasoned and formed natural wood, which is heat treated to achieve its maximum mechanical parameters. Carbon and wooden frame elements are manufactured at EMKY Bikes by layering specified amounts of fibres combined with epoxy resin. Carbon fibres are oriented so as to ensure resistance of the whole structure to any load as well as dissipation of vibrations generated when using the bicycle.