The problem of front derailleur position for full suspension bikes is as old as full suspension itself. Instead of concentrating on geometry, ride characteristics, optimum pivot placement and system integration, engineers have been forced to design frames around the front derailleur and its chainrings.
Nicolai and Bionicon, the new generation of innovators in drive trains and variable suspension, have also faced these problems since their very beginnings. As a result, an intensive exchange of ideas began after Eurobike 2003 with the aim of finally eliminating the troublesome front derailleur.
Kalle Nicolai’s company, UNIVERSAL TRANSMISSIONS GmbH (g-boxx.com), holds numerous patents covering alternative transmission systems for bicycle frames. BIONICON’s founder Andi Felsl has been a fan of his drivetrain concepts since their introduction in 2000, so it was a natural step to begin collaboration in 2004.
BIONICON’s (bionicon.com) aim was to create a fully adjustable and comfortable enduro chassis with a bottom bracket based drivetrain which is accessible to the broad public by utilizing Nicolai’s G-BOXX-2 technology.
Initially BIONICON’s task was to find an industrial partner outside the frame building industry to produce the G-BOXX. The first prototype from this co-operation was a Nicolai Nucleon featuring the Bionicon system and the G-BOXX. This bike is still ripping trails in Japan!
However both partners were unhappy about the high weight of the system for “Enduro” and “All-mountain” use. Discussion centered more and more on whether the rear derailleur really had to be replaced, as is the case with the current G-BOXX system, or if similar performance could be achieved by retaining the rear derailleur and cassette. After several heated exchanges Kalle and Andi finally agreed on the key ingredients for our vision of biking:
- Eliminate the front derailleur
- Optimal position of pivot points for all rear suspension systems
- Prevent chain from jumping off
- Lowest gear must correspond to 22 / 34 tooth ratio of a derailleur transmission
- Optimal climbing and highest degree of mechanical efficiency
- Rear derailleur with shortest possible cage
- Ergonomic handlebar shifting
- Target weight 1.2 kg incl. crank arms
- Can be fitted to “normal” frames with ISCG-mount
- Q-Factor (pedal width) same as normal derailleur drivetrain
- Maintain normal chain line
The collaboration fits perfectly to the philosophy of both firms: never define yourself through the components made by other manufacturers, envision the future and solve problems through your own innovations, and don’t wait for or expect others to find solutions.
So what is the B-BOXX all about? The B-BOXX is a fully enclosed, shiftable planetary drivetrain. It is mounted to the right hand side of the bottom bracket using a standard ISCG-fitting. A handlebar mounted push button allows the rider to choose between two gear ratios. The lower gear corresponds to that of a 22-25 tooth chainring; power is directly transferred. The higher gear multiplies every crank rotation by a factor of 1.65 and thus corresponds to a 36-41 tooth chainring. Shifting under power has been given close consideration throughout the development process. As with the G-BOXX-2 a patented magnetic activation of the freewheel teeth keeps B-BOXX shifting as smooth as possible. Those wishing to know more about this principle should look at the following video:
Finally, after a long 4 ½ year period of development we can present the B-BOXX at Eurobike 2008. Salvation for bikers and bike developers as well as a daily ride with a completely new dimension will follow in 2010.
source: Mic De Min CEO, BIONICON USA