5/30/2012 12:00:00 AM - TECH NEWS!
Understanding the BB386EVO
Why the industry is getting on board
FSA believes it's on to something big with the creation of the BB386EVO, yet many in the industry question the need for another bottom bracket standard. FSA's Claudio Marra explains why…
Can you tell us how the BB386EVO came about?
The idea of BB386EVO is based on the ground breaking BB30 system, developed by Cannondale. The revolution of the 30mm spindle opened the door for the most significant improvement in crank design in many years. The BB386EVO design simply modifies the BB30 design to a wider width, and incorporates a press fit bearing cup, rather than the direct fit bearing of the BB30 system. This slight modification allows the adaptability of the design to other BB shells, and gives the frame builder more options when crafting frames. The idea was born from a request from two separate FSA customers. The proposal was for a wider version of the BB30, but each requested different BB lengths. Both ideas were interesting, and the 86mm length allowed FSA to make one crankset that could also be used on threaded BB shells was chosen, thanks to the threaded reducer cups for 30mm spindles. Both customers agreed to FSA's suggestions and developed new frames based on this concept, while at the same time FSA created the crank set.
What were the ultimate goals of the new bottom bracket?
From the perspective of a frame maker, BB386EVO allows the designer significantly more area to modify the performance characteristics of the frame. A standard 68mm BB shell width allows a down tube or seat tube diameter of around 63mm as a maximum. The BB386EVO system allows a much more generous amount of area, up to around 83mm. This solution can really increase frame stiffness, and using the press fit cups allows the frame maker to eliminate any alloy insert into the BB shell, resulting in a big weight reduction. From the component maker's perspective, the BB386EVO system allows more flexibility of fit to more different frames. The BB386EVO uses the proven 30mm alloy spindle, which already is known to reduce weight and improve stiffness. Mating this to the wider BB shell, and press fit cups, allows this crankset to fit not only the 386EVOBB shell, but also to be adaptable to threaded frames, and to BB30 frames. The crankset is able to keep a normal Q-factor, and be adaptable to three different bottom bracket systems. As a result this crankset has the widest range of adaptability of any crankset we produce. Thus, the BB386EVO crankset can eliminate the need to offer different crank set models for the different BB standards. FSA will be able to offer one crankset that will fit all three, and still be lighter and stiff than our current MegaExo option.
What do you say to those who believe another standard for BBs unnecessary?
There have always been many standards of BB in the market. Those of us old enough will remember French threading, Swiss threading, as well as English and Italian. The bike market follows trends that continue innovation. As opportunities arise to really improve performance, or adaptability, we believe the industry will adopt them, provided they make sense. Thanks to this new standard, bike brands can have many advantages for their frame designs.
The BB shell is wider, what advantages does this bring?
The wider BB386EVO shell allows a much greater surface area, up to around 80-81mm of diameter, so the shape of the tubes can be modified more to achieve the ride performance they want. Additionally, other frame components can also benefit. The wider BB shell allows chain stays to be optimized, with either a greater thickness, or a wider spacing to allow greater stiffness, plus better tire clearance. One important characteristic of the BB386EVO design is that it allows a wide range of adaptability both for the crankset to fit other frame standards, and for the frame to fit other crank standards. The BB386EVO frame design allows the use of crank sets with the 24mm thick integrated spindle by a number of simple bearing adapters, which reduce the 30mm bearings to fit the 24mm spindle. Conversely, the BB386EVO crankset is widely adaptable to both threaded shells, and BB30 frames. FSA will also offer simple bottom brackets and adapters to allow one crank set to fit all three types of frames, thus simplifying both the sales and assembly process. The BB386EVO crankset will not only fit all of these bottom bracket types, but will also offer greatly improved performance compared to 24mm integrated systems, and reduced weight.
Which manufacturers have become early adopters of the BB386?
BB386EVO is already in use by Wilier and BH. ABG (Litespeed) is also now progressing with the standard and we expect other brands to take advantage of this design going forwards.
Why press fit bearings?
The use of the press fit bearing cups allows the frame designer to eliminate any alloy or steel component inside the BB shell area, since the nylon composite cups have a greater range of fit tolerance. Therefore, the BB shell area can become lighter, and simpler to make.
Could there be further tweaks to the design in future?
It is possible that other bike brands will propose enhancements to the system, and it is not a surprise. We suppose that in the future we will see more new standards introduced to the market.
Could the BB386 branch into territories beyond road?
It is possible that we will see this BB386EVO also on Cyclocross and MTB frames, since the benefits: weight reduction, stiffness increase and better clearance between the chain stays, make sense here also. Wider width designs, like BB386EVO, will have to work around interference issues with triple ring MTB cranks.
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