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The new K bike suspension - explained.


Firefight911

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For those that don't recall, I am of the camp for aftermarket suspension such as Ohlins, Wilber's, et al.

 

That being said, take a look at what the new K13 series of BMW is offering in the new ESAII suspension.

 

Sounds like the rate is adjusted through a rubber "bumper" setup. This would be the same thing they do in race cars (sort of) with spring rubbers to adjust corner weighting and therefore suspension control at each corner of the vehicle. Need to move the weight on the car, add or take away a spring rubber.

 

Interesting.

 

OK, here's the verbage. Consider the can opened!

 

Electronically adjustable ESA II suspension –

now adjustable at the touch of a button not only for spring

and damper action, but also in its spring rate.

 

Suspension is provided front and rear by extra-fi rm gas-pressure spring

struts on the K 1300 S. Spring travel is 115 millimetres or 4.52" up front and

135 millimetres or 5.31" at the rear.

 

In standard trim the rear spring strut allows infi nite adjustment of damping

forces in the rebound mode. And to adjust to various loads and forces,

the spring base may be varied by a hand wheel infi nitely over a range of

10 millimetres or 0.39".

 

As an option at extra cost the rider of the new K 1300 S may adjust not only

damping on the front and rear spring strut as well as the spring base (spring

pre-tension) of the rear spring strut, but now also the spring rate at the rear

and, accordingly, the “hardness” of the spring – and all this conveniently at the

touch of a button.

 

This is done by ESA II Electronic Suspension Adjustment setting the suspension

most conveniently and more precisely than ever before to the rider’s

particular preferences and the load the motorcycle is carrying. The result is a

new dimension of riding stability and excellent response under all riding and

load conditions.

 

ESA II is the world’s fi rst system for electronic suspension adjustment on a

motorcycle offering such a wide range of adjustment options: The rider is able

to adjust both the spring base and the spring rate as well as the damper

inbound and rebound motion on the rear wheel. On the front wheel, in turn,

adjustment is limited to rebound damping.

 

To make this control function as simple and straightforward as possible and to

avoid false settings, the rider only has to enter the current load condition

(“solo”, “solo with luggage” and “with passenger and luggage”.) Adjustment of

the appropriate spring base and spring rate is then automatic, with the system

adjusting the individual values to one another.

 

Depending on his style of riding, the rider may also choose the Comfort,

Normal or Sports mode, electronic management then applying this data to

determine the appropriate damping rates in accordance with the optimum

parameters saved in the Central Vehicle Electronics (CVE) and applying these

parameters accordingly.

 

In all, this allows no less than nine different adjustment variants on the new

K 1300 S.

 

Thanks to this additional adjustment of the spring rate, the ride height of the

motorcycle may be adjusted perfectly to various load conditions, ensuring an

even higher standard of riding stability, handling and comfort at all times. Even

under high load, therefore, this maintains the rider’s full freedom in leaning

over to a low angle in bends and thus allows a sporting style of riding. And last

but not least, adjustment of the spring rate dramatically reduces the risk of the

springs sagging and giving way.

 

The rider is even able to change the current damper setting (Normal, Sports,

Comfort) while on the road, again at the simple touch of a button. For

reasons of function and safety, on the other hand, the spring base may only

be changed when the motorcycle is at a standstill. While the damper

rate is modifi ed by small step motors on the damper itself, the spring base is

adjusted by an electric motor together with a special transmission.

 

The spring rate and its control map are modifi ed by a plastic element

(Elastogran) which, in combination with a conventional coil spring, takes up

forces in the inbound stroke. During the inbound stroke motion the defl ection

of this element to the side is limited, depending on the setting chosen,

by a sleeve pushed into position with the help of a step motor acting like

a stronger and fi rmer spring.

 

This almost completely eliminates any sagging motion of the rear end in the

inbound stroke and any change in suspension geometry otherwise caused

in this way. So with the rider adopting the same style and riding in the same

style, the K 1300 S is just as stable on the road when carrying its full load as it

is when the rider is riding solo.

 

Should the rider change the damper rate by pressing the button while riding,

ESA II will adjust the spring rate accordingly, again maintaining the normal

dynamic set-up of the suspension in virtually every situation. This is made

possible by a particularly powerful step motor in a position to vary spring rate

also under load. Accordingly, the appropriate spring rate is maintained under

all conditions with every damper setting chosen.

 

In the Sports setting the normal set-up of the machine is modifi ed for even

better handling and the rear end of the motorcycle is raised up. This shortens

wheel castor, which remains at the same consistently higher standard

regardless of the load the motorcycle is carrying.

 

Wheel load at the front, in turn, remains consistent, depending on the

spring rate chosen in advance. This ensures the same level of riding and

brake stability as well as superior steering precision at all times.

Additional adjustment of the spring rate provided by ESA II makes it possible

to increase the spread of settings in the Sports, Normal and Comfort

programs versus ESA I, the rider thus benefi ting from an ever wider range of

adjustment options on the road. In other words, the Sports mode offers even

greater dynamics and precision, the Comfort mode ensures an even higher

standard of comfort together with excellent stability.

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Not a mention of rebuildability in the whole blurb. So "the can" is effectively already worms out right from the word go!

 

Let's attach even more wiz bangs to a crappy shock. Yup, business as usual. Bring More Wallets

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Interesting that they are calling is adjustable spring rate. Is that because they are gas filled shocks... or air shocks? Is there an on-board air compressor like some luxury SUV's & cars have for leveling the car and cahnging ride height and ride quality?

 

If BMW was smart, they would consider creating a aftermarket division, that offers upgrdes on thetechnology for existing bikes. I know the market is designed to get customers to trade-in their rides, but why not consider allowing them to make upgrades when components wear out. I'm sure there's quite a few customers that might consider updateing to ESAII shocks for their GT's and RT's if a firmware update was available as well.... assuming there's ECU and compatability and enough I/O on the can-bus harness to the existing shock. Or offer a new supplemental wiring harness as well as part of the upgrade package.

 

Similarly, perhaps let customer customize other items such as final drive ratios, different wheel designs, and gasp... even seats.

 

Just a wild thought.

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russell_bynum

Very interesting.

 

Like Tony...I want to know:

1. Is it just more ways to adjust a POS shock, or are they finally giving us something worth having?

2. Is it rebuildable?

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Interesting that they are calling is adjustable spring rate. Is that because they are gas filled shocks... or air shocks? Is there an on-board air compressor like some luxury SUV's & cars have for leveling the car and cahnging ride height and ride quality?

 

If BMW was smart, they would consider creating a aftermarket division, that offers upgrdes on thetechnology for existing bikes. I know the market is designed to get customers to trade-in their rides, but why not consider allowing them to make upgrades when components wear out. I'm sure there's quite a few customers that might consider updateing to ESAII shocks for their GT's and RT's if a firmware update was available as well.... assuming there's ECU and compatability and enough I/O on the can-bus harness to the existing shock. Or offer a new supplemental wiring harness as well as part of the upgrade package.

 

Similarly, perhaps let customer customize other items such as final drive ratios, different wheel designs, and gasp... even seats.

 

Just a wild thought.

 

 

motoguy128, it sounds like the spring RATE is changed with some sort of urethane or rubber spring insert or wedge that can squeeze out of the spring at compression time.. The rate seems to be adjustable by a stepper motor powering a tapered cone up over that rubber insert therefore restricting it’s squeeze out displacement.. The less rubber that can squeeze out the higher the spring rate becomes (at least that is the way I understand it’s operation)

 

Adding air to air shocks increases the spring load but not so much the spring rate..

 

Twisty

 

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Here's all the info for the entire K13 model line -

 

LINKY

 

Well that explains the device on the shift linkage...

The K 1300 S features a new shift lever with an ergonomically optimized pivot point. Together with the likewise new anti-friction bearing for the shift lever this ensures an even more precise and faster gearshift than before. At the same time gearshift travel is even shorter and more dynamic.

 

For the first time in the history of large-scale motorcycle production by BMW and, indeed, for the first time in series production worldwide, the rider of the K 1300 S is able to shift up with the help of the optional HP Gearshift Assistant without operating the clutch and, accordingly, without the slightest interruption of traction and pulling force.

 

To perform this operation the ignition and fuel supply are interrupted for fractions of a second in the shift process. The HP Gearshift Assistant introduced for the first time on the HP2 Sport comes together with the sports footrests available as special equipment. Shaft drive to the rear wheel – optimized and quite unique in the sports segment.

 

Hope this tames the 1-2 & 2-3 up shift clunk.

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Very interesting.

 

Like Tony...I want to know:

1. Is it just more ways to adjust a POS shock, or are they finally giving us something worth having?

2. Is it rebuildable?

 

Smae question here...

 

Hope this tames the 1-2 & 2-3 up shift clunk.

Now it'll be easier than ever to find a false neutral :grin:

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russell_bynum
Here's all the info for the entire K13 model line -

 

LINKY

 

Well that explains the device on the shift linkage...

The K 1300 S features a new shift lever with an ergonomically optimized pivot point. Together with the likewise new anti-friction bearing for the shift lever this ensures an even more precise and faster gearshift than before. At the same time gearshift travel is even shorter and more dynamic.

 

For the first time in the history of large-scale motorcycle production by BMW and, indeed, for the first time in series production worldwide, the rider of the K 1300 S is able to shift up with the help of the optional HP Gearshift Assistant without operating the clutch and, accordingly, without the slightest interruption of traction and pulling force.

 

To perform this operation the ignition and fuel supply are interrupted for fractions of a second in the shift process. The HP Gearshift Assistant introduced for the first time on the HP2 Sport comes together with the sports footrests available as special equipment. Shaft drive to the rear wheel – optimized and quite unique in the sports segment.

 

Hope this tames the 1-2 & 2-3 up shift clunk.

 

Sounds like a standard quickshifter like most race bikes use.

 

I'm not sure why you'd want/need one on a street bike, though.

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russell_bynum

LOL! OK, I got it. Complexity for compexity's sake. A gizmo to impress your gizmo-centric friends. Like launch control on a street car.

 

OK, carry on.

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