Technique
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Parent Category: Technique
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Category: FSA
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Published on Wednesday, 10 February 2010 07:22
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Written by Luca Salvatelli
The revolution of FSA has identified a positive choice for lighter weight and increased rigidity
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The new range FSA cranks 386, is being heralded as a revolution in the world of mtb, like what was done in the road sector with compact cranksets. Until now double cranks for mtb develop on the same basis as the triple crank belongs to FSA have created a special room for the mtb. Reducing the number of arms that make up the spider and making a pair of crowns with a single bolt lap, FSA was able to get a lighter, stiffer crank than a comparable traditional model. Thus the arms of the roadster were reduced to three, compared to the classic 4, while the round bolts is 86 mm, only for the two crowns, compared to the classic pair of 104 and 64 millimeters. Thus was born the new 386 crankset is available with BB30 bottom bracket and MegaExo, versions K-Force Light and Afterburner in the two combinations of crowns 27/40 or 27/42. The development of these combinations metric shows the exchange ratio to lose a top and bottom. More or less, in fact, the 27/32 has a development close to the 22/32 metric, while the 42/11 has a development close to 44/12 Metric. The crankset is the model we tested K-Force Light MegaExo. This consists of the cranks hollow carbon fiber 3K, available in two lengths 170 and 175 millimeters, the central pivot is in CrMo steel with a diameter of 24 millimeters, while the bottom bracket bearings are ceramic type. FSA declares a weight of 632 grams FSA without central movement, we, with our instrumentation, have found 735 grams with bottom bracket, screws, spacers, etc.. and arm by 175 millimeters.
Road test
As tradition, the creation of the new crankset is excellent, with a perfect surface finish and a carbon fiber fully extended. Although the crowns are well implemented. The assembly is simple and just a bit of experience to better accommodate the derailleur, having the foresight to also adjust the screws at the end of travel of the derailleur cage itself. The reduction in weight than a traditional crank, for example the same FSA K-Force Light Traditional, is minimal and no appreciable road, but the most attentive to the weight of the bike as a whole and each component will welcome the approximately 30 grams saved. In apparent motion, as always, the perfect smoothness of the FSA MegaExo bottom bracket with ceramic bearings: one of the best middle movements in absolute smoothness and low weight. The stiffness of the cranks is excellent, and once well-adjusted the front derailleur, the steps of relationship, between 27 and 42, are fast and accurate. Moving emerging strengths and weaknesses of this solution, which satisfies and enhances the skills of the athletes stronger and more powerful, while it may be disappointing for cyclists. The first benefit is that it uses less the change, especially the derailleur, with a minor loss of time and a more useful phase of pedalling. Indeed, with 27 you can overcome all the steeper slope and you have a good metric development for areas less difficult, while 42 is used in the plain, sloping and descent. In fact, you can easily overcome the use of 22 and 32, subject however to be sufficiently powerful to give a final report very short. Here is the limit of double solution, however, universally adopted by all the best athletes in the specialty. The least powerful, least-trained, can find the solution improper because the relationship would be short, however long, while the others benefit from a less intensive use exchange rate and the opportunity to focus more on driving performance and ride. The relationship longer, you will lose, however, affects less, the stronger will have to act more on pedalling frequency (but more on very steep slopes and little techniques), while the less powerful are already using it with little or nothing. Rigidity, then, this crankset is very high, to the benefit of the transmission of power. Like all products in carbon, however, is very good, strong and stiff if they apply forces in the right direction, that of the pedal and could be fregile in case of fall, with heavy swing. Is, this, a problem of cranks and carbon components, durable beyond belief, until receiving a blow not included in the project .... The same can be said of the surface resistance with greater ease to scratch, perhaps over a simple output chain. Those who prefer the reliability and security at a low weight, please contact the Afterburner model, aluminum, heavier but more reliable in many respects. In conclusion, the new 386 crankset seems that keeps its promises: it is lighter, more rigid and sliding of the corresponding traditional model. In the race could be faster because, in addition to the increased rigidity and smoothness, is used less use of the derailleur, but can be a handicap for the amateurs who may suffer less powerful than the loss ratio shorter. The price is around 500 euros (price already on offer at a shop on line) is hight but aligned to product quality and not just over the traditional model. For the amateur point out that the model aluminum Afterburner, with a weight greater by about 140 grams, has a cost (always discounted on line) about 200 Euros, and may be the best solution for an enthusiast looking for a good value/price/reliability.
Positive aspects
Build quality
Weight
Stiffness
Smoothness
Less use of the exchange
Negative aspects
The athletes will suffer less powerful than the lack of a final report shorter
To learn more:
FSA
Website: www.fullspeedahead.com
