Electronic suspension is a reality on some production bikes, whether it’s push-button adjustment like various ESA-equipped BMWs and Ducati’s Panigale offer, or more sophisticated, semi-active systems like BMW Dynamic Damping Control (DDC) or Ducati Skyhook Suspension (DSS) that automatically adjust suspension action in response to real-time riding conditions. It’s clearly the wave of the future.
But as revolutionary as the above systems are, each is limited to a specific motorcycle. Swedish suspension giant Öhlins hopes to make electronic control (EC) accessible to a wider range of riders with its new Mechatronic rear shock, the first aftermarket electronically controlled suspension. The Mechatronic is currently available only for 2011-2013 Kawasaki Ninja ZX-10Rs, but Öhlins expects to add more applications in the near future.
The Mechatronic shock uses the same ECU as Kawasaki’s electronic steering damper, which wa
The Mechatronic ECU piggybacks on the Kawasaki ECU and leverages the same data used by the bike’s traction-control and ABS—including throttle position, engine rpm, wheel speed, and more—to interpret the rider’s actions and adjust the suspension accordingly. The ZX-10R was selected because Öhlins had designed the electronic steering damper for the 2013 version of that bike and already had an intimate knowledge of that bike’s CAN bus electrical system. Öhlins embedded the suspension software logic into the steering-damper ECU, so the Mechatronic shock installation is plug and play on the ’13 bike. (Mechatronic shocks for the 2011-2012 ZX-10Rs include an ECU and wiring harness at no extra charge.)
Mechanically, the Mechatronic shock is identical to the standard TTX36 (twin-tube) damper, except for the addition of stepper motor-driven compression and rebound adjusters, which makes it simple and surprisingly economical—at just $1625, the Mechatronic shock costs less than $200 more than the standard TTX36 shock. The remote preload adjuster is the same as the non-electronic shock, as is the ability to change shock length to alter ride height.
Because there is no spring-travel sensor, gyro, or other means to monitor suspension movement, the Mechatronic system does not react to bumps directly. Instead, it reacts to dynamic changes in how the bike is ridden and increases or decreases damping to suit. This isn’t as sophisticated as BMW’s DDC, and the reaction isn’t nearly as fast. The Mechatronic actuators take .2 seconds to enact a damping change, compared to a lightning-fast .001 seconds for BMW’s more sophisticated electromagnetic damping valves.
The Mechatronic shock operates in two modes: Comfort and Sport, with damping action dictated by different algorithms in each. The Comfort algorithm provides a plush ride. Sport settings optimize acceleration, grip, and stability during braking and cornering. Comfort is the base mode; when aggressive throttle action or rapid acceleration indicates an “active riding threshold” has been crossed, the Mechatronic ECU switches to Sport mode and increases damping. When the rider returns to more casual riding, the shock ECU switches back to Comfort Mode.
Damping rates are constantly changing in both Sport and Comfort modes. That is, the shock does not use just one group of settings for each mode. Depending on engine speed and rate of acceleration, for example, the Mechatronic ECU consults a set of algorithms to change compression and rebound damping dynamically. The two modes really determine how the dynamic adjustments are bracketed.
And while you can’t make individual damping adjustments as you would with a normal TTX36, you can slightly game the system. On the ZX-10R, with the power mode in Full, the system is quick to switch from Comfort to Sport, and will hold Sport longer after the algorithms determine sporty riding is over. In Low power mode, the system is slower to switch from Comfort to Sport; in Medium, it largely splits the difference. The assumption is that you’re not going racing in Low mode.
This technology moves Mechatronic riders one step closer to the Holy Grail of perfect suspension response for any road, at any time. It’s like having an on-board suspension tech fiddling the clickers while you ride, which is a huge advantage for the vast majority of riders who don’t have the skill, ability, or desire to become their own suspension expert.
Any static suspension set-up represents some compromise between comfort and performance. Electronically enabled semi-active suspension systems reduce these compromises by altering suspension damping on the fly in response actual riding conditions, dialing in a plush ride for bad roads or a relaxed pace and a firmer set-up under aggressive riding conditions. The dynamic responsiveness eliminates any need to manually adjust set-up for different riding situations, like commuting and track days.
Mechatronics In Motion
Is Öhlins’ New Shock Really Magic?
Words: Aaron Frank
Photo: Peter Jones
Öhlins’ Mechatronic technology is rooted in racing, and was used by Yamaha’s World Superbike team in 2008 (before being banned), but the aftermarket shock isn’t for racers. It’s intended for street riders and trackday enthusiasts who don’t know how to—or don’t want to—adjust their suspension, but still want their bikes to work well across a wide range of riding conditions. The Mechatronic press intro reflected what might be normal usage for a sportbike owner: A street ride combining Interstate and canyon routes followed by a track session at Streets of Willow Springs.
There’s no outward indication of what mode—Comfort or Sport—the Mechatronic shock is in, and changes are so transparent it’s impossible to tell what the shock is doing at any given moment. The only time you feel Mechatronics working is when starting the bike. There’s no damping until you turn the key when, if you bounce the bike, you can actually see the shock stiffen mid-stroke.
Heading north from Valencia on Interstate 5, at a constant speed and small throttle opening, the shock is almost certainly in Comfort mode, and absorbs expansion joints and the occasional Botts’ dots with the plush compliance of a Gold Wing. Exiting at Castaic on Lake Hughes Road, we’re able to exercise the throttle more enthusiastically, presumably crossing the “active riding threshold” that shifts the shock into Sport mode with its more aggressive damping strategy.
Braking hard for an unexpectedly tight corner, the lightly loaded rear wheel keeps good contact with the road and stays right in line, the shock presumably dialing damping back enough to let the wheel follow the irregular surface. We arrive at Streets of Willow Springs and venture on track without adjusting anything beyond tire pressure. Mechatronic’s logic defines a rear shock setting that seems exactly right for racetrack pace. Streets’ fast-and-bumpy bowl sometimes ties big bikes in knots. A too-soft shock packs down and causes a bike to run wide on the exit, but the self-stiffening Mechatronic is stone stable, rocketing the 158-bhp ZX-10R out of that corner perfectly on line.
Better grip and stability at high speeds paired with unprecedented plushness at a casual pace highlight the Mechatronic’s versatility—not even Öhlins’ excellent TTX36 offers this without stopping to make adjustments. The biggest shortcoming of the Mechatronic shock is that it only works on the rear of the bike. Here’s hoping the engineers in Sweden are hard at work on a bolt-on Mechatronic solution for the front end.