And responding to customer input, BMW Motorrad is poised to develop further rider assistance features in the future.
The first step in this direction is BMW Motorrad ASC Automatic Stability Control, available as early as next year. This is the first system in the world to control driven wheel spin on a production motorcycle, and will be introduced as an option on touring models in the BMW K and Boxer (R) Series motorcycles.
BMW Motorrad has drawn on the vast experience of Continental-Teves, which has been instrumental in developing braking and traction systems for motor cars for many years. Work on the motorcycle project began in earnest in 2003, with the company working closely with BMW Motorrad to devise an ideal solution for two-wheelers.
BMW Motorrad's new Integral ABS technology has been developed separately from the previous system and the entire layout of the system has been newly conceived from the ground up. Capitalising on progress in technology in both hydraulics and electronics, the development engineers have succeeded in simplifying the architecture of the system while at the same time enhancing its functions to an even higher standard. The result is supreme stopping power and very short stopping distances even without electrical power assistance for the brakes.
BMW's integral ABS is no longer based on the plunger principle or, respectively, the ram pressure process used on previous generations, but instead is conceived as a valve system. It ensures a very high standard of all-round comfort and convenience. In particular, brake pressure modulation feedback at the brake lever has been reduced by the development of the control valves and management, removing unpleasant effects. It is so efficient and smooth it has been introduced on the top models in the BMW Motorrad range.
The new Integral ABS system applies brake pressure on the front wheel brake solely by means of a hydraulic circuit, thus acting entirely in response to the force applied by the brake lever. Sports riders will enjoy this new level of control and feedback response. It also means riders who switch between machines with and without ABS should notice no difference in braking operation.
The new system naturally maintains the proven semi-integral function. This provides automatic activation of the rear-wheel brake when the front brake lever is operated. Depressing the footbrake alone activates only the rear brake.
As with the previous system, the advantages of this integral brake are ideal brake force distribution on both wheels under all conditions, naturally taking load conditions into account.
It also gives early warning of the rear wheel lifting when braking harshly, allowing the rider to take appropriate counter-action.
To provide the desired integral function, brake pressure for the rear-wheel circuit is generated and built up by an electronically controlled hydraulic pump.
This offers the advantage of pressure management and control completely independently of the front wheel circuit - which is the prerequisite for dynamic, adaptive, and ultimately, consistently ideal brake force distribution to the rear wheel as well as fully independent brake management and control.
In the event of any deficiencies in the hydraulic pump or electrical components, the rear wheel brake acts hydraulically as with a conventional system, overriding the integral function.
This has no effect on the proper operation of the front wheel brake, the only difference being that the ABS function is no longer operative in the event of such a deficiency.
BMW introduces ASC for motor-cycles.
Automatic Stability Control is a meaningful, additional assistance function, particularly useful for a high-torque motorcycle and when riding on slippery surfaces. ASC is the logical counterpart to ABS.
Automatic Stability Control prevents the rear wheel from spinning in an uncontrolled manner when accelerating hard, and thus avoids any loss of grip or stability which could lead to the wheel spinning out of control.
Lift-off detection and intervention serves furthermore to prevent the front wheel from coming up when accelerating under full power. Acting together, these two functions enhance riding stability and thus help to ensure a higher standard of safety on the road. Of course the rider is able to deactivate the ASCt any time, even on the move.
Like ABS, ASC is also subject to the immutable laws of physics, especially while cornering.
The ABS wheel sensors determine the speed at which the wheels are turning. Registering any sudden change in the difference in speed front-to-rear, the electronic control unit is able to detect any risk of the rear wheel spinning. The immediate response is to interrupt the ignition to reduce engine power.
If this is insufficient to restrict wheel slip, fuel injection is also interrupted.
This kind of control and management is fast and sensitive, with only minor impact on riding comfort or dynamics.