How does motorbike stability control work?

While stability control has been mandated in all new cars in Europe since 2014, motorcyclists have had to wait, despite being far less stable than cars. Many motorbike models still don’t even have antilock brakes, let alone other technology that helps prevent a skid.

The basic premise of stability control is a system which allows you to brake and turn without causing a skid and it proved quite tricky to master on two wheels. Bosch introduced a system called MSC (Motorcycle Stability Control) on a KTM 1190 in 2013 which went one step further than traditional antilock brakes which struggle when the lean angles are extreme. Preventing the wheels from locking reduces the chance of a lowside accident when the bike slips from underneath the rider.

MSC also features traction control. Spinning up the back wheel when exiting the corner is an excellent recipe for a highside crash so traction control all but eliminates these types of crashes.

MSC measures five main parameters:

• Braking pressure
• Acceleration
• Pitch angle
• Lean angle
• Wheel speed

Programmed within the system are a set of equations that determines when you have exceeded the limit of the bike/tarmac interface. For example, if the rear wheel suddenly accelerates much faster than the front wheel, then wheelspin is possibly occurring. Conversely, if one wheel stops turning much more quickly than another, then overbraking is occurring which results in a skid. If the rear wheel accelerates but the front wheel does and the sensors indicate the bike is tipping backwards then MSC backs off the power because it knows the bike is pulling a wheelie. If the front brake is applied heavily and the rear wheel appears to lift off the ground then MSC will adjust the power to maintain full braking with both tyres contacting the road.

Read more about efficient motorcycle braking in this article.

Maximising braking and accelerating forces

MSC distributes brake force between the two wheels to the limit which means that it can deliver the maximum braking force available in respect of the road surface. The system understand braking on an slope at any angle and braking on loose surfaces such as gravel roads. Riders that want to get into hard core off-road riding can enable Enduro mode which allows for a locked rear wheel to help with turning.

MSC prevents the bike’s tendency to move upright under heavy braking, a phenomenon that widens the cornering radius. Hill hold control helps when starting the motorbike on a steep uphill.

MSC prevents accidents within the realms of normal to aggressive riding, but it can’t compensate for lack of foresight by the rider, or situations where another vehicle puts the motorbike rider in a situation where physics cannot be overcome. However, in these situations the rider can be assured with full confidence that dropping the anchor will result in the maximum brake power being applied while still retaining the ability to steer, and this will scrub off as much speed as possible and give the rider options to find an escape path.

This video gives a demonstration.