What's the difference between 1k, 3k, 12k and UD
Carbon fiber is measured by the width of the weave. For instance, a 1K weave will be approximately 1mm in width
while a 12K weave will be much larger at approximately 12mm and so forth.
The outer layer of any carbon frame serves several purposes.
The first purpose is to provide a cosmetic layer of carbon giving the frame it's final look.
Secondly, it provides a final touch to the ride of the bicycle.
Some weaves are more rigid than others and some weaves flex more providing more supple ride characteristics.
Some people will say that the weave you choose does not make a difference in overall ride quality.
If that is the case then our Fascenario 0.7 and 0.8 should produce the exact same stiffness numbers,
as they are made the same with the only difference being the outer layer of carbon.
The fact is that the 12K carbon used in the Fascenario 0.8 makes the bike stiffer and can be seen in stiffness-to-weight measurements.
The K-factor – what is 1K, 3K and 12K?
Over the last couple of years marketing people have used terms such as 1K or 3K when writing about carbon.
This specifies the number of miniscule fibers (filaments) used in one roving. 1K stands for 1000 filaments, 3K for 3000 and so on.
These rovings are then biaxially interwoven to make a carbon fabric. The differences between the fabrics are mainly in the looks.
UD – what’s the story?
UD is short for unidirectional. This means, that all the filaments lay parallel in one direction, no cross fibers or weaving.
Things such as 1K, 3K or 12K are therefore of no importance at all.
The only thing of relevance is the total of fibers used, that’s the weight of the plies relative to the area.
This is something marketing writer usually do not mention though.
UD is different to fabric not only because of its look, its mechanical properties are also different:
In a fabric the fibers are slightly bent because of the weaving.
This leads to a slightly reduced tensile strength, the fibers are not as straight as would be ideal.
Fabrics with their mesh of filaments stop cracks better in the case of failure though.
UD fibers may therefore be not a bad idea for frames, where more than one tub supports the weight of the rider.
The failure of one tube does not necessarily lead to a crash. For our parts we are not happy with the UD trend.
If so desired we will make handlebars and seat posts with a UD surface layer,
we will always use fabric underneath for safety reasons, it helps to prevent „brittle” breaks and a rapid expansion of cracks.
1K -1K is a very rare fiber used in the cycling industry.
It is lighter than other fibers and provides a more supple ride than a larger weave.
These smaller carbon fibers also display the incredible amount of craftsmanship needed to complete one of our bikes.
The Fascenario 0.7 is the only model in the Storck line that features this coveted carbon.
2K - 2K is the rarest carbon fiber available on the market. It is produced by no more than 2 carbon manufacturers in the world.
The Fascenario 0.7IS is the only bicycle in the world featuring this carbon.
2K carbon provides the optimum ride characteristics to pair with our VVC frames.
This gives the bike perfect stiffness, low weight, and great vertical compliance (comfort).
3K - 3K is the most common carbon fiber that you will find externally on a bicycle.
It provides a comfortable ride while still allowing the bike to be stiff and strong enough
to handle a powerful rider in the midst of his/her best sprint.
12K - 12K is the largest weave and the stiffest.
This outer layer featured on the Fascenario 0.8 makes for the stiffest "feeling" ride of all three.
It is slightly heavier and much less expensive to use in production,
hence the price difference in the Fascenario 0.7 and the Fascenario 0.8.
Uni-Directional - Uni-Directional (UD) carbon is another type of carbon fiber that can be used to create a carbon bicycle.
UD carbon has fibers that run the same way rather than being woven together.
This carbon is used on the Fenomalist and Aero UD in the Storck line-up.