• Frequently Asked Questions
    • Occasional delamination on hand-made tires may occur. When are these considered Warranty issues? Are there particular things to avoid doing to hand-made products in order not to mis-handle the product?

      CHALLENGE tires are HANDMADE. We are one of only a couple of factories in the world mastering this ‘artisan-like’ manufacturing process.  Because we consider of prime importance maintaining the rubber’s natural properties intact, we avoid whenever possible, heat treatment vulcanizations and produce by a handmade process.

      Normally other tires are mostly industrially produced using this heat treatment called ‘vulcanization process’ which helps ‘glue’ everything together.   But, while this vulcanization process finishes and glues the tire parts together more thoroughly, it also dries and hardens the rubber some, reducing the rubber’s grip (of particular importance for a performing tire), its shock-absorption properties and ultimate comfort feel.

      Making handmade tires is a difficult process and we pay constant attention to each step and detail.

      Nevertheless a few small problems may occur that are imperceptible and that QC (quality control) inspection during the various production phases do not notice.

      The tread is applied manually by hand and therefore human error may occur involuntarily and however is rare.  These cases are below 1% but, we are constantly working to reach the target of close to 0%.

      The problems refer to minimal parts of the tread coming unglued on new tires.

      - This may happen because, when applying the tread to the casing, the worker may have touched the side of the tread improperly and removed a bit of glue with his finger. The adhesion at QC check looks ok, but then on first use the problem becomes more perceptible.

      - Another reason can be that the tire may come in contact with a chemical agent, such as the solvent, when cleaning the ribbon and applying the glue to the cotton tape. The solvent is also used afterwards to clean the tread area after gluing it to the tape.

      All these processes, when not done extremely carefully, may weaken the glue in that certain area and involuntarily contribute to a slight problem later.

      This is not a manufacturing problem but a minimal % of human error when handling the product.

      Other things may occur when an end user mishandles a perfect product. These are high-end, handmade products which require to be handled with proper care!

      - Often users (or even mechanics) clean the bikes and tires with high pressure water guns. The pressure is at times too strong, and when pointed directly to the tread of the tubular or tire for long time to clean it, the very high pressure pointed on one spot (and especially to the sides) may eventually end up creating a problem sooner or later.

      - There are also cases of bikes being washed with detergents that contain degreasers and these are chemicals that must not go in contact with the tires!

      These are the most common problems of mishandling or improper cleaning of handmade tires. 

      In most cases factory defect tires are warranted by us and replaced immediately, but we do ask for a few photos and description of each problem as it is quite easy for us to determine whether it was a factory defect problem or a mishandling problem, in which case we are a little less happy to warrant.

      These situations are related to handmade tires made by us or our competitors and they are known. They are part of the handmade process and no matter how accurately you work on it, very slight human errors or mishandlings may occur.

      And on the other hand, no matter how much you communicate to the market, it is difficult to ‘train’ 100% of end users and/or occasional mechanics about products they are not always so familiar with, so they may also be occasionally mishandling.

       

    • What does TPI stand for?

      The TPI (Thread Per Inch) is the number of Threads in each Inch of lenght of the casing. The TPI is traditionally used as a parameter to determine the quality of a tubular and of a tire in general. To a higher number of Threads correspond a better quality tire.
      The Corespun is a technical fiber, very soft and resistant. It's made with a poliester inner soul and a second cotton fiber that surrounds sit. A corespun casing is much more puncture resistant due to the increased resistance of the fiber and to the thikness of its structure. Softness and flexibility are also improved.
      The tubular with a softer corespun casing can be inflated with slightly higher pressure without loosing grip and confort.
      "Softness" is a key issue on high performance tires. As a matter of fact, the deformation of the tire and the constant contact patch allows increased grip and confort. Rigid tires tend to loose contact with the ground, loosing grip as a consequence.
      Despite the increased number of threads, Criterium 320 tubular is about 10 grams lighter than the previous 300 TPI version.
      The TPI is important but it's not the only one feature when we look at the quality of a tire. The Compound used for the tread is important as well. A new Carbon High Tech compound has been developed to perfectly fit the new corespun casing and give the best of the performance. With this new super soft compound the tubular has a perfect grip doesn't matter if you are riding on wet or dry ground, and a very low rolling resistance is granted at the same time.
      The traditional tread design, that has made our Criterium Challenge famous over the years, remains unchanged.

    • What is “handmade”?
      The main feature of "handmade" tubulars is that no vulcanisation treatment is done, except for the one done separately to the tread before it is applied to the finished casing.

      First the single ply is made on the loom, using only the warp held together by a latex coating which replaces the conventional weft.

      Subsequently two single plies are attached together in a round shape and the threads of each ply are placed to form a herringbone pattern.

      This new coupled ply is then pressed with hot cylinders, cut to the desired size and the edges folded for subsequent sewing.
      The finished casing is obtained by sewing the two edges of the ply together, inserting the inner tube at the same time.

      The ribbon is manually applied to cover the stitching, and to serve in the future to glue the tubular to the rim.

      The finished casing is mounted on a rim and then inflated. The tread, separately prepared, is manually applied and the tubular is now ready!