With the return to the spotlight of weight marks and the arrival of bikes, again, lighter, the limit of 6.8 kg that the UCI sets for competition bicycles is back on the table and recovering the We have been going through a debate for years about whether this is an appropriate limit or whether technology allows us to make lighter bikes without them ceasing to be reliable.
Will we see weighted bikes again in the World Tour?
Let’s go back about a decade. Before aerodynamics, disc brakes or internal wiring took over practically all bike designs on the market. A time in which knowledge of the capabilities of carbon fiber began to definitively take off and manufacturers began to use this material in its full capacity and not, as had been done until then, simply transfer manufacturing systems and structures that were applied to aluminum and steel frames with carbon tubes.
From then on, the bikes underwent a leap in evolution and allowed them to be refined to the limit, a limit that the UCI was in charge of setting, for competition bikes at 6.8 kg, determining, according to their studies, that with the technology of that time That was the minimum figure that a bike had to weigh to be completely reliable and manageable.
At a time when cyclists began to carry lighter bikes, we even saw much lighter weight crazy setups. Even brands launched production bikes that lowered that figure and that, to be used in competition, had to be ballasted and thus reach the minimum weight. Who doesn’t remember that “Legalize my Cannondale” campaign with Saeco cyclists dressed in a prisoner’s jersey in allusion to the illegal weight of the Six13 model, made with a carbon main triangle and an aluminum rear?
The emergence of aerodynamic bikes began to make it more difficult for competition machines to approach the UCI limit of 6.8 kg as there was more material to achieve the profiles that reduced resistance. Something that also contributed to the widespread use of high-profile wheels. However, what ended up taking competition bikes away from those weights was the arrival of disc brakes and completely internal wiring that have made practically all the bikes on the market gain weight.
However, now brands are once again focusing on reducing the weight of bikes, without giving up all the aerodynamic gains and technological innovations incorporated over all these years. This is possible thanks to the emergence of better qualities of carbon fibers, the appearance of new resins that manage to give greater cohesion and resistance to the frames and the evolution of manufacturing processes, with more precise studies thanks to simulation programs. finite elements with which it is possible to use each gram of material by eliminating them from where they are not necessary.
The result is frames with a level of lightness that was inconceivable just a few years ago, but not only that, they also meet rigidity or absorption parameters in line with the requirements of a competitive cyclist.
Is the limit obsolete?
With all these evolutions in bicycle manufacturing technology, the question, already raised at the time, is once again whether that figure of 6.8 kg that the UCI sets as the minimum weight for bikes makes any sense. The answer would be yes and no. On the one hand, the existence of a limit restrains brands from the temptation to exceed the limits.
In the past, when this debate was in full swing, it was not unusual to test some bikes weighing around 6 kg. If you were a light and small cyclist this was not a problem, but if you were a big cyclist it was common for carrying these bikes to be an exercise in technique, sometimes proving tremendously unstable and difficult to drive when the speed increased.
However, at that time there were no advanced studies using FEA software nor were differentiated laminates developed for each size. Nowadays, brands give the importance that corresponds to behavior and all bikes have to meet certain requirements for rigidity and absorption, so each size of the bike is a different development with different laminates. That is to say, no one is going to lighten a bike just for the sake of lightening it if that is going to mean a decrease in its qualities.
On the other hand, the UCI, as a control body, now requires that all bikes that are going to be used in competition must be certified by them. To do this, manufacturers must send designs and frames on which tests are carried out and it is verified that they comply with the technical regulations before giving them approval and being able to show off the characteristic sticker that almost all frames on the market seek to show off on their tube. saddle.
Brands also have test laboratories, some even with scanner and x-ray machines, not only to verify that the frames they build meet the parameters set as requirements but also to analyze when a breakage occurs to determine the cause and take action. corrective if necessary.
It is clear that everything can fail and there are still bikes that break, however, a catastrophic failure, for example a fork or a frame breaking suddenly while we are riding, is something extremely unlikely.
With all these evolutions and controls, it could be planned that the elimination of the 6.8 kg limit should not mean that manufacturers would go crazy with weight, especially due to the culture that performance does not depend only on weight and neither cyclists nor Manufacturers are going to penalize force transfer or wind penetration just to gain a few grams. We have the proof in the bikes of recent years where professionals have been competing with bikes clearly above 7 kg.
Source: www.brujulabike.com