Optimum control by means of 16 sensor pulses per revolution
On the basis of the recently launched FAG inner bearing BB 29, Schaeffler Group Industrial has developed the compact speed sensor bottom bracket bearing BB RS with noncontact measurement of speed, direction of rotation and angle of rotation. The system generates 16 pulses per shaft revolution and thus has a significantly higher resolution than previous solutions, allowing more precise control through shorter response times in activating and deactivating the drive system. As a result, the drive system can respond with significantly greater sensitivity to the individual riding characteristics of the cyclist and thus offer optimum assistance. The system is also capable of distinguishing between forwards and reverse pedalling and can include this information in the output signal.
Compact and well protected
In contrast to previous solutions (normally a magnetic disc with a Hall sensor) which are openly accessible and therefore sensitive to external influences, the FAG sensor bottom bracket bearing is a completely encapsulated system that can be accommodated in the design envelope of a conventional bottom bracket bearing. The sensor is thus optimally protected, kept secure from disruptive influences and completely maintenancefree. Once the system is fitted, it is ready for operation without the need for further adjustment. The twin core cabling is located within the frame, giving optimum protection. The supply voltage is between 5 and 18 volts (rated voltage 12V) and is thus compatible with all conventional control systems.
Easy to fit
Mounting is particularly easy due to the connection preventing reversed polarity and the dual fix design. The housing profile is suitable for the use of FAG tools (externally) and Shimano tools (internally). Since the diameter at the centre of the bearing unit is significantly reduced, this allows space for light cables and other connections. The plastic housing with glass fibre reinforcement compensates small mounting tolerances and makes mounting easier.
Excellent smoothrunning characteristics
Like the standard smoothrunning inner bearing BB 29, the new sensor bottom bracket bearing BB RS is characterised by excellent smooth running. This is due to the optimised bearing arrangement. In contrast to conventional bottom bracket bearings, there is no need to clamp the bearings in the frame. This design has a positive effect on the smooth running of the bearing and ensures that the rider expends significantly less energy reaching his destination.
The new FAG sensor inner bearing BB RS is available with immediate effect from manufacturers and in the near future via distributors in the aftermarket. It will be presented to the public for the first time at the trade fair Eurobike in Friedrichshafen, 1-4 September 2010. In addition to this entry level model, other FAG sensor bearings will be launched there that, in addition to the functions of the BB RS, can also measure torque on one or both sides.
Please visit Schaeffler Group Industrial at Eurobike in Friedrichshafen, 1-4 September 2010, Hall A5, Stand 102.