Technique

Test: FSA Crankset Afterburner Vs FSA Afterburner BB30

Details

Parent Category: Technique

Category: FSA

Published on Monday, 31 August 2009 08:16

Written by Luca Salvatelli

We have compared the two Mtb cranks from FSA Afterburner, the classic and BB30, here are the differences

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The crank Afertburner FSA

The crank is characterized by Afterburner cranks aluminium made by forging blank inside, and this solution allows to obtain permits to have the cranks with a good stiffness-weight ratio, significantly higher than the traditional cold forging, but filled with cranks. The aluminium used is 6061/T6 spider hay and then finished with a CNC machine. Round bolt is 104/64 millimeters and crowns are made of aluminium in sizes 22/32/44 and 26/36/48 (this combination only for the traditional model). For both there are two lengths of cranks 170 and 175 mm. The factor Q (the distance between the two cranks) is 169 millimeters and chain line is 50 mm. The differences reside in the central spindle and bearings.

The conventional pin has integrated CrMo steel 24 mm in diameter with bearings from the same external diameter. The BB30 version, however, has pivot alloy (Aluminium 7075) by 30 millimeters in diameter with bearings of greater diameter (30 millimeters always) and to a lesser thickness. Both have made them in the grey glossy finish on this photo. With our equipment we found the following weights, with 175 mm cranks and bottom bracket complete with dies and everything needed to complete the installation:

Afterburner traditional : 913 gr

Afterburner BB30: 876 gr

  

The differences between the two models

The substantial difference between the two models is the different standard, traditional and BB30, which leads to a different central pivot of steel for the traditional version with a diameter of 24 millimeters, while the BB30 version is using a pivot aluminium with a diameter of 30 mm. This leads to BB30 as a lower weight of the central pivot, but also to its greater rigidity. The bearings of BB30 are located internally and not externally as in the traditional movement and this leads to a number of advantages. The BB30 bearings are larger in diameter and smaller thickness, the overall weight of less of the classic external caps and offer the advantage of less absorption of energy. The fact that they have an increased diameter leads them to have even a longer period than the traditional caps of the traditional model. Obviously the standard BB30 should only be used on a chassis with the BB30 bottom bracket, which can accommodate inside the bearings from the inside diameter of 30 millimeters. So if there are adapters on the market to mount a traditional crank on a BB30 bottom bracket is not possible to do the reverse, as a physical buffer of the standard BB30 not physically enter into a traditional bottom bracket, designed to accommodate the diameter bearings Internal 24 mm and 30 mm. The difference in weight, finally, considering that we tested two models are identical, it is not negligible, considering the increase in stiffness.

Road test

Like any product FSA achieving the two cranks is perfect, with aluminium worked perfectly, well polished and cared for each component in detail. The installation instructions are detailed and the same ease he shows who has a minimum of practical mechanics. As always it is better to run an assembly with careful painstaking preparation of sites, cleaning them and checking (and possibly correcting) the premises housing the bearings. It 'always good, then, follow the tightening torques, suggested by the home, avoiding unnecessary approximations, using the brakes where the fillet is not already taken from the house (many parts are already equipped with brakes fillets blue). After adjusting the height of the derailleur and synchronization of that you can leave. In reality this operation should not essre necessary, but it is good to do a complete revision of passages of the report to verify that everything is in place. The conventional impressive because of its rigidity and crank the excellent smoothness of the bottom bracket. The passages of the report are still accurate and facilitated by the particular shape of the tooth crowns. A good crank and can lead to rigidity and fluidity, with similar projects of equal price, compared to showing overall higher for both overall and for visual quality. The same positive note to be found on the BB30 model that still offers more strength and smoothness. Nothing so obvious, but noticeable. In this it is noted that the standard BB30 leads to a different chassis, with a box of the bottom bracket much larger and designed, all of which helps to improve the rigidity of the group frame-bottom bracket-cranks, consequently leading to improved performance . These are achieved through smaller bending or twisting of the above together (it is detectable only minimal movements instrumentally) that have as a minor aspect of energy dissipation which is best transferred from crank to rear wheel and a lower energy absorption for 'friction bearings that work better, thanks to its larger size is due to the fact that remain better aligned with each other and less prone to twisting, which will inevitably compromise the smoothness. All this leads to a superiority of fluidity and rigidity of the standard BB30, compared to the traditional standard which also has the disadvantage of greater weight. Remain unaffected ease of passage of relationship and trust, which should even be increased in accordance with FSA studies which provide high duration BB30 bearings. This increased duration is determined by the lowest speed at which they run the same cadence pedalling compared to the standard normal minor speed determined more by their own diameter.

Conclusions

Both FSA Afterburner cranks have proved both valid; hard, sliding and well made. The traditional model is very competitive and no doubt winning the competition of equal price. In addition to the increased rigidity and has a sliding surface and, thanks to special processing of crowns, quick passes and quick ratio. BB30 The model is generally higher than the already excellent traditional model. Presents a lower overall weight, improved smoothness and stiffness. On the latter point is important to note that the implementation of the housing of different bottom bracket acts to stiffen the whole structure and to extend the rigidity of the crank-bottom bracket. Although, inevitably, the two cranks have been tried on different frames but basically the same price range, you can then assert the superiority of the standard BB30 than traditional. With minor differences, it is true, but certain. Considering the need to buy a new bike for the medium high range seems logical to prefer models with the standard BB30. And is well being in mind that minor differences it makes little sense to construct a bike with a standard BB30 and components of the medium low. But this offers undeniable advantages in terms of weight, stiffness and smoothness. Who does not want to switch to the standard BB30 or wants to make an attractive up-grade of your bike with the box of traditional central moviment find, however, in the model Afterburner, a valid and successful, even in comparison with many competitors.

Price

Positive aspects (reference to both models)

Weight

Construction quality

Stiffness

Fluency

Negative aspects (referred to only model BB30)

Unfortunately the standard BB30 is still not widespread

Are suitable for

Athlete: for light weight and stiffness are two excellent products for the agonist with a slight advantage for the model BB30.

GF cyclist tourist: two excellent products with excellent price and excellent reliability, without chasing the highest performance standard is more than excellent for the amateur.

For further informations:

Website: www.fullspeedahead.com