X1-INT 2 Kit


Availability: 10 in stock

SKU CST010 Category Tag


Center-fine C-C
XS 68 43 51,5 75,3º 71,5º 10 40,5
S 71 46 52 74,9º 72º 12 41
M 73 48 53,5 74,3º 72,9º 12,5 41
L 75 50 55,2 77,2º 73,1º 13,5 41
XL 77 52 56,8 76,4º 73,3º 14,5 41,3


  • Direction
  • Seat post
  • Fork
  • Saddle clamp

Do you want another kit with your bike? Contact us and we will advise you


The X1-INT frame was born from the designer's rebellion against the evolution of bicycles designed in the age of aluminum, where road bike manufacturers, in search of rigidity and lightness at the same time, developed frames with excessively large diameter pipes, thus losing its classic aesthetic elegance of a road bike.

Costantino wants to show that in the era of Carbon and composite fibers, the bicycle sector can take advantage of new materials and technology while maintaining the classic aesthetics of the road bike, with the benefits demanded by today's cyclists. The frame that at first glance looks retro has the highest modern technology, being a Monocoque , which has an integrated seat tube and a notable widening at the tube joints to offer greater lateral rigidity.

The special characteristic of the X1-INT is that it is one of the few frames on the world market that is made with Monocoque technology, which means that it is truly built a single piece, in a single step, without previous phases in its manufacturing process.

This process has the particularity of offering a structural continuity that provides a multitude of advantages to highlight:

  • Greater comfort.
  • Greater rigidity.
  • Minimizing the chances of human error in the manufacturing phase.
  • Refined aesthetics.
  • Reduction of aggression with the environment.
  • Decrease in weight.
  • As it does not have union areas, it lacks possible squeaks.

An important phase in the process of making the painting is the stratification of the fabrics pre-impregnated in resin, which amount to up to a hundred tiny pieces of varied shapes with different mechanical characteristics, which vary according to the functionality of each piece and the site that occupy inside the frame structure.


Once the stratification step is finished, the frame is subjected to a heat treatment of 140 ° C in an autoclave (vacuum container) at a pressure of minus 6 bars of vacuum. This technology allows to create a composite structure with a perfect exterior finish, and a homogeneous compaction of the interior sheets throughout the entire frame, which gives it a fundamental characteristic of mechanical resistance.


The end result is the birth of a very special painting, based on the wisdom of the choice of materials, on the type of fabrics and on the correct placement at the key points of various pieces inside the painting.


Pictures that at first glance seem the same as ours, may have some differences that only an attentive and expert eye can identify, and sometimes neither, due to the fact that the differences are found in the internal structure of the painting. Materials can be noticeably different from ours, without realizing it. These differences can make a mockery of those manufacturers who say that their frames are monocoque when they really know they are not, and they also use cheaper materials that can seriously reduce the mechanical properties of the frame and have terrible consequences imaginable.

The X1-INT frame meets all the technological and aesthetic requirements worthy of our times.