Front suspension: One smart shock and one dumb?

On my 2020 RS, I see wires entering the top of the front left suspension shock, but just a cap for the right shock.

Is only the left side actively controlled as part of the electronic suspension?

I'm sure they're all like that (well BMW's, anyway). Mine are.

Yes. Not sure how much damping is done in the right fork, but only the left one has the servo motor to adjust it.

It is not just a question of sensing the axle movement, as the system then has to respond to that with real time adjustments to the damping. Having only one leg wired up clearly implies that only that leg has the electronically controllable damping components.

Probably the other leg either only has a spring, or maybe has a baseline amount of passive compression and rebound damping which is less than the minimum required, with the adjustable leg providing the rest.

A lot of conventionally suspended bikes with manually adjustable damping have compression damping in one leg and rebound in the other, so it is not unusual to rely on the mechanical links between the two legs to share the forces involved.

Same is often true with mountain bike suspension forks. Air spring on one side, damping control on the other.
It saves cost and weight not duplicating the expensive precision bits.
Provided the fork is sufficiently rigid (the Fox forks on my Orange 5 struggle under my excessive weight).

It is clear that most of us at least do not really know how the front suspension is configured or how it works.

I'll display my ignorance with this supposition. The side that has the wired is the one that adjusts the preload (one helmet, two helmet etc) The other side is the more or less conventional dampener , with factory preset compression and rebound settings.

I don't believe there is any "dynamic" adjustment done on the front suspension.

I hope some one who really knows can explain this to us.

My take on this is
Ride height and damping sensor is at the rear of the bike via a thin rod attached to the swing arm.
Only the rear shock adjusts for ride height (preload) not the front forks
The front fork with the wire in it has the spring, oil and adjustable damping in it (but no sensor as it’s all done at the rear
The other fork just has a spring and oil and either fixed or no damping.
Finally it’s all connected to the handlebars with string and pulleys and levers and a sprinkling of magic fairy dust.
I think that’s about it.

I'm sure you could get the answers to all of your questions from Ted Porter. His shop specializes in BMW suspension. https://www.beemershop.com/

It is true that only the rear shock has electronic adjustment for preload and that it has what is described as a level sensor attached between the shock/swingarm and the frame. The GS also has one of these at the front to get more accurate information of the front suspension movement, even though there is no preload adjustment at the front. It would be interesting to know if the level sensor also provides information on the extent and speed of suspension movement to assist in calculating the optimum damping settings, maybe together with IMU data.

Interestingly the Showa EERA suspension used on the Africa Twin supposedly has the ability to sense movement without the need for an external sensor, though I have not been able to find out whether the damping on that is simply electronically switched between predetermined preset levels or if like other manufacturers such as BMW, Ducati and KTM it is dynamically tweaked many times per second. If the former, just electronically selected presets, then I think they should not be describing it as semi-active.

Zitat von fred_jb im Beitrag #10

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It is true that only the rear shock has electronic adjustment for preload and that it has what is described as a level sensor attached between the shock/swingarm and the frame. The GS also has one of these at the front to get more accurate information of the front suspension movement, even though there is no preload adjustment at the front. It would be interesting to know if the level sensor also provides information on the extent and speed of suspension movement to assist in calculating the optimum damping settings, maybe together with IMU data.

Interestingly the Showa EERA suspension used on the Africa Twin supposedly has the ability to sense movement without the need for an external sensor, though I have not been able to find out whether the damping on that is simply electronically switched between predetermined preset levels or if like other manufacturers such as BMW, Ducati and KTM it is dynamically tweaked many times per second. If the former, just electronically selected presets, then I think they should not be describing it as semi-active.

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