The new rear wheel steering patents from BMW Motorrad might aid in tighter turns, motorsport, stunt riding and potentially, aerodynamics too
BMW Motorrad, the motorcycle division of BMW, has patented rear-wheel steering technology for motorcycles. BMW showcased rear wheel steering with chain driven, belt driven and shaft driven motorcycle layouts. The main intention seems to be achieving a lower turning circle and enhanced handling and motorsport.
You must have seen Hyundai’s e-Corner system demonstrated on an Ioniq 5. Will motorcycles get to do all that too? Let’s take a look.
BMW Motorrad working on rear wheel steering on motorcycles
We can see a couple of use cases. For example, BMW patented this tech with sketches of a cruiser bike. Maybe BMW got this idea after they launched the R 18 cruiser range. Makes perfect sense as a cruiser has a long wheelbase, large rake angle, and small trail angle. These make maneuverability an absolute nightmare.
This is where this rear-wheel steering setup comes into play the most. BMW patents mention potential gains in aerodynamics. They can cover the front wheel now. Given that it has a lower steering angle as some of the task is handed to the rear wheel as well. The patent also mentions rear wheel steering benefits in motorsports when the front wheel is in the air.
According to BMW, rear wheel steering will provide improved steerability when riding on the rear wheel with the steerable front wheel in the air. This wheelie aspect will definitely impress Character Ali from Dhoom 1. BMW has an electric motorcycle patent too. Both the electric bike and rear wheel steering are yet to hit production.
Limitations of such a mechanism
Apart from complexity, cost, weight and maintenance, I can think of some other potential issues with this system from an engineer’s perspective. Primary of them is swingarm strength as BMW’s patented rear wheel steering mechanisms will replace conventional swingarms.
A rider turns motorcycles with lean and shift of body mass to make a turn. This is what we are used to till now. Making the shift to a new steering method is like fighting with your instincts and muscle memory. We might need a lot of time to transition to riding this new motorcycle steering mechanism than what we’re currently used to.
People who use counter-steering methods (example, steering right to turn left) can adapt to this new steering system better. But counter-steering folks are very very few. Also, stuntmen who drag and drift a lot and off-road riders who lock rear wheels to steer motorcycles, can quickly adapt to this new mechanism.
BMW’s patents reveal multiple methods to achieve this rear wheel steering. There were double-sided and single-side mechanisms with physical linkages to the handlebar for steering inputs. Also, there was one patent with electrical assistance for rear wheel steering too, which negates physical linkages as it can take steering input from a steering position sensor like in a car.