What's all this ESA anyhow?

[Engineer]

What's all the ESA stuff anyhow?

Cribbed this from BMW's press release - I applaud BMW for it's commitment to innovation but it would seem to me that there is an awful lot of interactions here and that I am not sure I am yet ready to trust the 'feel' of my bike to such a system. As an Electronics Engineer I'd love a more detailed explanation of what the actual dynamics of the system are.

"Semiactive suspension:
BMW Motorrad Dynamic ESA for optimum riding dynamics in every situation as an ex works
option and BMW Motorrad Integral ABS as standard.
With the optional Dynamic ESA, BMW Motorrad offers an electronic suspension which taps
into a whole new range of possibilities as well as providing maximum riding safety and
performance. This semiactive suspension monitors the vertical movement of front and rear
wheel control in travel and speed as well as other parameters by means of a spring travel
sensor in each position and adapts the damping automatically to the situation depending on
riding conditions and the manoeuvres being carried out by the rider. Dynamic ESA also
responds to an ABS control brake manoeuvre, for example. Damping adjustment of the
spring struts at front and rear is effected by means of electrically controlled regulation valves.
The drastically improved contact between road and tyres means that the new R 1200 GS is
able to provide a previously unequalled sense of security on very uneven roads and when
riding off-road.
Dynamic ESA does not work as a self-contained system, but is able to communicate with the
other control systems of the R 1200 GS – BMW Motorrad ABS as well as Automatic Stability
Control ASC – via CAN bus.
What is more, the basic settings of Dynamic ESA are linked to the riding modes “Rain”,
“Road”, “Dynamic”, “Enduro” and “Enduro Pro”, which can be conveniently selected by the
rider at the press of a button. Each of the riding modes gives the rider a damper setting as
recommended by BMW Motorrad experts. The mode switch can be used to adapt the overall
characteristics of Dynamic ESA, engine control (characteristics), ABS and ASC to the given
situation by selecting the various modes with their respective settings. What is more, the
damper setting can be tailored to personal preferences in all modes, ranging from “soft” to
“normal” and “hard” by means of the “ESA” switch on the end of the left handlebar. The load
settings for one person, one personal with luggage or two persons are also set using this
switch, just as the rider prefers.
In “Rain” mode, the dampers have a soft basic set-up. In order to ensure maximum safety
when accelerating, ASC is set for early control intervention in “Rain” mode. ABS is adjusted
for use on the road.
If the rider selects the “Road” mode, Dynamic ESA shifts to a tighter setup. ASC ensures
optimum traction on dry roads and the ABS is also configured for road use.
In “Dynamic” mode, Dynamic ESA provides an even tighter damper setting which is entirely
geared towards a sporty style of riding on the road. In this profile, ASC characteristics are
further tightened, even enabling experienced riders to perform light drifts. Here again the
ABS setting is geared towards road use, while also providing a more dynamic throttle
response.
The “Enduro” mode provides a high-traction damper setting for off-road riding. Here ASC
provides for more slip on the rear wheel, allowing light off-road drifts. The ABS setting is
designed for running over loose surfaces such as gravel with road tyres, which have a higher
approved level of slip. As on the road, the ABS operates with a part integral function: in other
words when the front wheel brake is activated, part of the brake force is directed to the rear
wheel. This is a feature which offers a high level of safety over rough terrain, too. Here the
control strategy is designed so that wheel lock is prevented while still allowing effective
deceleration. Increased ride stability and a greater sense of trust are the pleasing result
An additional coded plug enables the rider to access the “Enduro Pro” mode for more
ambitious off-road riding. This setting provides significantly increased bottom-out reserves.
In this mode - reserved solely for off-road use with studded tyres - experienced motorcyclists
can deliberately make the rear wheel of the R 1200 GS break out due to ASC intervention
adjusted to professional enduro use. The ABS characteristics are specially adapted to this
type of sporty use since control is specifically geared towards riding on loose surfaces with
studded tyres. What is more, ABS does not act on the rear wheel when the rear brake is
applied. Deactivation of the part integral function means that the front and wheel brake
operate entirely separately from one another, in keeping with the preferences of an
experienced enduro rider, also allowing so-called initial brake drift before hairpin bends.
And when the coded plug is used, the individual Dynamic ESA setting is preserved over a
change of riding mode. Without the coded plug all settings are set to default, e.g. when
turning off the ignition. ABS and ASC can be manually disengaged by the rider in all modes.
With the coded plug inserted, the systems remain deactivated when restarting the bike after
having turned off the ignition before."

 

[jonnyp]

It's obviously way beyond an old timer like you...






Offers open to take mine out !!

 

[krytengs]

I am not sure I am yet ready to trust the 'feel' of my bike to such a system.

It probably "feels" more Setup, than most humans can achieve with a spanner

 

[Captain Beaky]

It does actually work in practice, you can feel the suspension stiffen up when you chuck it around, and then soften once you are back on the straight and narrow. It very much the usual GS "helping hand" than an intrusive feature.

All this technology isn't new - all the major car manufacturers have been doing it since 2000 ish - evan on the simpler cars we have variable throttle progression, to make parking and low Speed driving smoother, we have had variable rate power steering for a while too. All these systems rely on interactions from other systems and sensors. Par for the course now.

BMW put a non- active system on the last model. All it did was switch a servo in the shock into a firmer setting. I seem to remember playing with the ESA on a TC when I had a test ride, setting it to Hard for a string of roundabouts, and then Soft for the motorway.

With the LC, it's a bit more intelligent - stiffens it up when you need it, and softens it up when you don't ( or when you are hard on the brakes.)

Also, the ESA allows you to alter the preload too - I'm not so interested in this.

I'm an electronics engineer too- I try not to think about each and every interaction on my cars and bikes - i do that as my job - i dont want to do it all the tome though! i want to get on with the job of enjoying the bike - enjoying the fact that it does interact to make it a nicer ride.

Give it a go, but if youve got a TC, you might well feel that the LC is not worth the upgrade.

But you never know till you try it.

 

[batman1]

Is there a way to alter the load height ie the helmet' symbols while on the move, or do you really have to park the bike to do it!

Oh! Did I mention it's just x3 sleeps after tonight 'til she arrives!

 

[patzx12]

Is there a way to alter the load height ie the helmet' symbols while on the move, or do you really have to park the bike to do it!

Oh! Did I mention it's just x3 sleeps after tonight 'til she arrives!

No, its like the TC set helmets at a standstill

 

[Engineer]

It does actually work in practice, you can feel the suspension stiffen up when you chuck it around, and then soften once you are back on the straight and narrow. It very much the usual GS "helping hand" than an intrusive feature.

All this technology isn't new - all the major car manufacturers have been doing it since 2000 ish - evan on the simpler cars we have variable throttle progression, to make parking and low Speed driving smoother, we have had variable rate power steering for a while too. All these systems rely on interactions from other systems and sensors. Par for the course now.

BMW put a non- active system on the last model. All it did was switch a servo in the shock into a firmer setting. I seem to remember playing with the ESA on a TC when I had a test ride, setting it to Hard for a string of roundabouts, and then Soft for the motorway.

With the LC, it's a bit more intelligent - stiffens it up when you need it, and softens it up when you don't ( or when you are hard on the brakes.)

Also, the ESA allows you to alter the preload too - I'm not so interested in this.

I'm an electronics engineer too- I try not to think about each and every interaction on my cars and bikes - i do that as my job - i dont want to do it all the tome though! i want to get on with the job of enjoying the bike - enjoying the fact that it does interact to make it a nicer ride.

Give it a go, but if youve got a TC, you might well feel that the LC is not worth the upgrade.

But you never know till you try it.

I am not anti ESA I just want a detailed technical explanation before I become a 'believer'.

I have an LC but it's the standard basic model and it's performance and handling is bloody good - much better than my previous TC. It seems to me from the BMW press release that the number of inputs to the dynamic ESA are large and varied, this means that there must be a huge number of possible 'dynamic' states, so how can one be sure that they they are all optimum for any particular situation?

Does anyone have a complete explanation of how this system actually works?

 

[Appman]

I am not anti ESA I just want a detailed technical explanation before I become a 'believer'.

I have an LC but it's the standard basic model and it's performance and handling is bloody good - much better than my previous TC. It seems to me from the BMW press release that the number of inputs to the dynamic ESA are large and varied, this means that there must be a huge number of possible 'dynamic' states, so how can one be sure that they they are all optimum for any particular situation?

Does anyone have a complete explanation of how this system actually works?

Have you ridden th TE to see what it's all about? If so which of the available modes is your bike fixed in? Or which one is closest?

Sure we're all interested to hear your results

 

[knucklemoto]

I always loved Kevin Ash for his technical and engineering insight (much missed), here's an article he wrote a while ago:

http://www.ashonbikes.com/content/bmw-semi-active-suspension-ddc

And here's a simple video explaining the basic relationship between the variables involved.

http://www.youtube.com/watch?feature=player_embedded&v=9wdQZAgs0dk

Hope these get you started.

 

[karlp]

I am not anti ESA I just want a detailed technical explanation before I become a 'believer'.

I have an LC but it's the standard basic model and it's performance and handling is bloody good - much better than my previous TC. It seems to me from the BMW press release that the number of inputs to the dynamic ESA are large and varied, this means that there must be a huge number of possible 'dynamic' states, so how can one be sure that they they are all optimum for any particular situation?

Does anyone have a complete explanation of how this system actually works?

You will probably not get an explanation for quite a few years as I suspect it is commercially sensitive information..

Why not try Ducati and see if they will tell you how it works.

Or better still just test ride a GS as convince yourself

 

[Flipfly]

I am not anti ESA I just want a detailed technical explanation before I become a 'believer'.

I have an LC but it's the standard basic model and it's performance and handling is bloody good - much better than my previous TC. It seems to me from the BMW press release that the number of inputs to the dynamic ESA are large and varied, this means that there must be a huge number of possible 'dynamic' states, so how can one be sure that they they are all optimum for any particular situation?

Does anyone have a complete explanation of how this system actually works?

I wouldn't take that as completely detailed, it doesn't mention anything about them being able to charge you a small fortune when it goes wrong
Read the blurb on the enduro mode, it says nothing about the different throttle feel, what haven't they mentioned about the suspension

Imo technical stuff written by advertisers is advertising with a little bit of technobabble for the masses.

 

[roundincircles]

I am not anti ESA I just want a detailed technical explanation before I become a 'believer'.

I have an LC but it's the standard basic model and it's performance and handling is bloody good - much better than my previous TC. It seems to me from the BMW press release that the number of inputs to the dynamic ESA are large and varied, this means that there must be a huge number of possible 'dynamic' states, so how can one be sure that they they are all optimum for any particular situation?

Does anyone have a complete explanation of how this system actually works?

That's interesting......the words optimum for a given situation.

The guy or girl writing the software decides what is optimum and others may disagree.

My guess is that most riders want an 'improvement' with dynamic ESA and it does deliver in my opinion but I doubt if it is optimum in a given situation and also optimum would be different for different riders.

Hand grenades this way.

 

[Engineer]

I always loved Kevin Ash for his technical and engineering insight (much missed), here's an article he wrote a while ago:

http://www.ashonbikes.com/content/bmw-semi-active-suspension-ddc

And here's a simple video explaining the basic relationship between the variables involved.

http://www.youtube.com/watch?feature=player_embedded&v=9wdQZAgs0dk

Hope these get you started.

That's useful info thanks - seems like it is only the damping that is dynamic, which makes sense to me.

I just wonder what the settings are adjusted to, if say, one is travelling upright at 100mph and the front wheel is forced upward by a 1" short bump in the road, does the dynamic suspension respond at all? and if so what is adjusted and by how much and in what direction?

It would just make it easier for me to understand the system a little better.

 

[Captain Beaky]

Yes, only the damping is dynamic.

I think you will find that it's all a tad simpler than that. I think the shock only has a few settings, probably soft, normal and hard. The dynamic bit is probably pretty simple in terms of the adjustment that it can carry out.

Again, this is how many car manufacturers do it. There is a small solenoid valve in each shock, and the ecu simply turns it on and off as required to harden up the handling when chucking it around or when you press the sport button ( which usually just spoils the nice ride and makes it all hard)

The simple hard/soft type of system actually provides a marked improvement without adding too much complexity. Also, being a simple solenoid, it can act very quickly, and tends to be quite robust.

It's not really amazingly clever and infinitely adjustable - what's clever is working out when you want to shift modes.

Only a few really expensive cars have fully adjustable dynamic damping.

I've found this kind of system can be very effective on the cars I've driven with it fitted - best of all was the Citroen xantia vsx my mate had. It had this fancy hydraulic anti roll bar - no matter how hard you cornered, the car would always remain flat to the road - no body roll at all - in reality, all the system did was to close a valve which stopped the cross-car flow of hydraulic fluid, thus giving a really nice anti roll feel.

I have to admit, I was skeptical at first - if I had decided to buy a TC, I wouldn't have ordered the ESA, but the dynamic system on the LC does make quite a difference for the better.

Cost to replace the parts - I'm not worrying about that just yet...

What is clever is the adaption of the abs too.
Especially the off road mode that allows the back to lock up but maintains the anti lock on the front - I wish my xr250 had that...

The one thing I'm not 100 percent sure of is the changing of the throttle progression to make it feel like the bike has more power. Rain mode? I'm not paying this much money to ride around with less power!
I've not enjoyed that feature of any car I've driven - in fact I've modified my Saab to remove it. It's just plain annoying on cars.
However, i retain an open mind we will see how I fair on the gs when I eventually get it...U

 

[Wrinkly]

I'm no Techno wizard and usually stay well clear of anything I don't understand.
However,after having ESA on my TC and likeing it I opted to go for the "Dynamic ESA" on my WC.

There is a particular road that I ride regularly, it's a single track and at times very undulateing lots of gnarley bits etc

Honestly the way the WC covers this road compared to my TC is a revelation.

Sorry I can't explain it technically but I do know what the seat of my pants tells me.
It's brilliant.

Steve

 

[Captain Beaky]

It's a sign that BMW did a good job - when you don't know what it's doing - other than feel that it's doing something good.

That's what I thought on the test ride - I first realised that it was handling really nicely - then the analytical bit of me started to work out why - what was the bike doing...

 

[Engineer]

I wonder if the front damping adjusts to short sharp changes at high speed - surely the event is over before the system can react in time to do anything useful at the front - so does the rear damping get a tweak in response to high speed events at the front in anticipation of the rapidly approaching disturbance?

I suspect that at a steady high speed the systems just stays neutral and only responds to relatively low speed changes like lean angle.

 

[Captain Beaky]

You are probably right.
It won't be THAT fast.

And besides, it's not the compression you really want to worry about in that circumstance - it's the recovery, and the bumps that follow.

 

[GrinningGSer]

Dynamic ESA: I assume it is different from DDR on the HP4 otherwise they's both be called DDR
Does dynamic ESA have a lean angle sensor? DDR certainly does.

 

[The Grey One]

Yes, only the damping is dynamic.

I think you will find that it's all a tad simpler than that. I think the shock only has a few settings, probably soft, normal and hard. The dynamic bit is probably pretty simple in terms of the adjustment that it can carry out.

Again, this is how many car manufacturers do it. There is a small solenoid valve in each shock, and the ecu simply turns it on and off as required to harden up the handling when chucking it around or when you press the sport button ( which usually just spoils the nice ride and makes it all hard)

The simple hard/soft type of system actually provides a marked improvement without adding too much complexity. Also, being a simple solenoid, it can act very quickly, and tends to be quite robust.

It's not really amazingly clever and infinitely adjustable - what's clever is working out when you want to shift modes.

Only a few really expensive cars have fully adjustable dynamic damping.

I've found this kind of system can be very effective on the cars I've driven with it fitted - best of all was the Citroen xantia vsx my mate had. It had this fancy hydraulic anti roll bar - no matter how hard you cornered, the car would always remain flat to the road - no body roll at all - in reality, all the system did was to close a valve which stopped the cross-car flow of hydraulic fluid, thus giving a really nice anti roll feel.

I have to admit, I was skeptical at first - if I had decided to buy a TC, I wouldn't have ordered the ESA, but the dynamic system on the LC does make quite a difference for the better.

Cost to replace the parts - I'm not worrying about that just yet...

What is clever is the adaption of the abs too.
Especially the off road mode that allows the back to lock up but maintains the anti lock on the front - I wish my xr250 had that...

The one thing I'm not 100 percent sure of is the changing of the throttle progression to make it feel like the bike has more power. Rain mode? I'm not paying this much money to ride around with less power!
I've not enjoyed that feature of any car I've driven - in fact I've modified my Saab to remove it. It's just plain annoying on cars.
However, i retain an open mind we will see how I fair on the gs when I eventually get it...U

I have only just spotted this but as a Citroen Anorak I had to reply! The Xantia you are referring too must have been an Activa model. These had Citroen's Hydractive suspension system which used electronics to alter the spring and damper rates by switching between using the two suspension spheres and a third centrally mounted sphere both front and rear. The system received inputs from a speed sensor, brake sensor, body movement sensors and from the steering-both angle of rotation of the steering wheel and speed of rotation.

The active suspension (anti roll) as used in the Xantia Activa models had a hydraulic cylinder forming a link in the rear anti roll bar. Despite what some might believe all self levelling Citroens had anti roll bars front and rear. It is the twisting of the bars that is used, by a mechanical link, to work the height correctors which control the ride height.

On the Activa models the hydraulic cylinder forms the link between one end of the bar and the suspension. The electronics adjusted the amount of fluid within the cylinder to keep the vehicle level. There was no cross flow of fluid involved.

Sorry this is a bit late but I hope it makes things a bit clearer.

John