ESA Testing the shocks?

I have ESA in my 1200, its done 15K

It could just be down to imagination but I get the feeling that whilst the suspension is working in respect of it bounces on the springs and the height adjusts as it should when you change 1 rider 2 rider luggage etc, I suspect there may be an issue with the shocks as particularly when riding solo it seems to thump (not a loud bang) but doesn't seem to absorb particularly the sudden bumps.

Is there any test that I can do or is it a case of getting a dealer to look at it. If you sit on it and put it in comfort mode for instance and then bounce up and down it does bounce but on the downward it seems to come to a firmer stop that I imagine it should; not something I have notice before but you know what it's like you tune into things.

Any suggestions?

Thanks

You can see if preload is adjusting for luggage / two up by measuring the sag at rear. I linked to a video on this in another suspension thread, but if you can't find that then google - pretty simple just to see if there is a difference mode to mode. But I suspect that isn't your issue

Sport / comfort mode etc changes the damping settings meaning that the shock compresses and extends more or less easily. For example, if you hit a bump on comfort you should feel less of it in your backside than if you hit the same bump in sport. This is because the compression setting is different and the shock is compressing more slowly on the higher setting.

Testing this is harder. You can test rebound typically by compressing the rear and timing how long it takes to re-extend - 1 sec is what is generally aimed for. But I don't know if ESA alters rebound very much, and this may not be easily testable if changes are small (typically rebound alters 1/3 or so of compression in most shocks with combined damping).

Testing the compression damping is what you want, and this you can only really do by feel. You can try seeing if there is an obvious difference when you push down on rear of the bike on different settings, or you can ride the same piece of road at same speed over same bumps and compare.

My guess, and it is just a guess, is that the shock needs a service and what you are experiencing is not any ESA malfunction, but the symptoms of nitrogen pressure reducing and oil aging (btw do feel your shock the next time you ride hard - it gets a lot hotter than you would expect). Even though under 20k, the nitrogen will escape over time and most aftermarket shock service intervals are around 20k anyway.

If it helps, think about whether bumps feel round or square edged - if on comfort mode you feel like the bumps in road are square edged (like the back kicks when you go over them) then the shock likely does need a service.

Have a look around the bottom shock and see if there is any oil residue from a leak.

Also don't be afraid to use what I call small bumps preload setting for a softer ride. My bike is 2008 GS, ESA. (preloads are 1 helmet, 1 helmet with luggage, 2 helmets, Small Bumps, Big Bumps) Recently had rear shock rebuilt and on recent 2 up touring I forgot to switch back to 2 helmets mode when getting back on tarmac and thought the bike was more comfy and handled fine with Small Bumps. Switched to 2 helmets for test but was happier with Small Bumps

With regard to the pre-load settings. Am I right to think that as you move from 2 helmets, to small bumps to big bumps, the pre-load just keeps increasing send the bike gets taller and taller?

Or is it more sophisticated than that?

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Pottsie said:

I have ESA in my 1200, its done 15K

It could just be down to imagination but I get the feeling that whilst the suspension is working in respect of it bounces on the springs and the height adjusts as it should when you change 1 rider 2 rider luggage etc, I suspect there may be an issue with the shocks as particularly when riding solo it seems to thump (not a loud bang) but doesn't seem to absorb particularly the sudden bumps.

Is there any test that I can do or is it a case of getting a dealer to look at it. If you sit on it and put it in comfort mode for instance and then bounce up and down it does bounce but on the downward it seems to come to a firmer stop that I imagine it should; not something I have notice before but you know what it's like you tune into things.

Any suggestions?

Thanks

Click to expand...

Maybe if you have somebody close by with a GS-911 that could do a ESA calibration for you, might be as simple as that.

Slipperyeel said:

With regard to the pre-load settings. Am I right to think that as you move from 2 helmets, to small bumps to big bumps, the pre-load just keeps increasing send the bike gets taller and taller?

Or is it more sophisticated than that?

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Click to expand...

Not quite.

1 helmet = 10% preload front and rear.

2 helmet = 50% preload rear. 10% front

2H+Luggage = 90% preload rear. 10% front.

Small bumps = 50% preload front and rear.

Large bumps = 90% preload front and rear.

That's helpful to know - Is it only the preload that alters or does anything else change too?

There are two different motors on each shock one does the preload, the other the damping. This is true for later WP shocks, may be different for older Showa shocks. Therefore when you change the preload settings only those change obviously. I don’t know how or by how much the damping varies between each of the three road settings, or between the two off road settings, or if there is any overlap but suspect there are only 3 levels of damping in total.

Thanks, slowly getting my head around this (I think) : I can feel the difference if I change the normal, sport and comfort setting; does this alter preload or damping?

AustinW said:

Not quite.

1 helmet = 10% preload front and rear.

2 helmet = 50% preload rear. 10% front

2H+Luggage = 90% preload rear. 10% front.

Small bumps = 50% preload front and rear.

Large bumps = 90% preload front and rear.

Click to expand...

Interesting. Thanks. I really need to cycle through the settings on mine because I'm sure that the last time I did it, on high bumps/ mountains the front lowered? . I'm hoping it was in fact in one helmet and I somehow I missed it!

Meanwhile, it all seems to be behaving...

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Headtester said:

Thanks, slowly getting my head around this (I think) : I can feel the difference if I change the normal, sport and comfort setting; does this alter preload or damping?

Click to expand...

No. Those settings only adjust the damping. In my case, I really notice the difference. I could tell you the difference without seeing which setting it was on...

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Slipperyeel said:

No. Those settings only adjust the damping. In my case, I really notice the difference. I could tell you the difference without seeing which setting it was on...

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Click to expand...

Thanks again, So if I've understood this the normal, sport and comfort settings alter the damping. The helmet, luggage and bumps alter the amount of preload?

Headtester said:

Thanks again, So if I've understood this the normal, sport and comfort settings alter the damping. The helmet, luggage and bumps alter the amount of preload?

Click to expand...

Yup..

Headtester said:

Thanks again, So if I've understood this the normal, sport and comfort settings alter the damping. The helmet, luggage and bumps alter the amount of preload?

Click to expand...

As AustinW mentioned, it's not linear. With the small and high mountains settings, there may be damping adjustments too, meaning comfort/ normal/ sport mean something slightly different in those pre-load settings

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Thanks for all the input chaps, I did think I said thanks earlier but clearly didn't hit the button. NicD's info very interesting and fills in a few gaps in my knowledge as have subsequent posts, much appreciated.

I thought I'd bite the bullet and take it to a dealer for their view, it may be that I'm just imagining the thud on the smaller bumps but I'd see what they said. Dealer 1 north of me who usually service it said that the don't know of any fault that may cause these symptoms but said they could book it in for mid September (about 2 weeks after the holiday I told them about) and they let me know if anything needs replacing. Dealer west a little from me explained that they may need calibrating and that it would be £100 per hour but that if this electronic process didn't resolve it then they'd let me know to leave it so they could do further investigations. Dealer 3 south of me started by saying the best thing I could do was bring it in and they'd take it for a test ride; they'd then be able to confirm if there was anything need doing but either way I'd have to wait a week (not an issue). I then went on to query re-calibrating etc. and he said there is no such thing, they're either working or they're not in which case they would have to investigate. Final shot was at local reputable bike dealer who are no longer BMW franchised but who still do a lot; they'd just had to replace someones RT suspension and started by telling me this could a 4 figure sum repair. None of this has endeared me to BMW franchises or given me any confidence that any of them really know what they're doing. Oh and dealer 1 told me to beware other Motorad Dealers because many had not got the full updates on their systems anymore and this can negatively input the work they do! There's simply no standard!

I replaced the shocks on my 2011 GSA when I had somewhat similar symptoms to you. Generally the bike didn’t feel right anymore. Sudden Bumps in the road caused thumps and judders and what felt like bangs with the bike generally just unsettled the whole time.

I went for Wilbers where you buy a shock specified for your weight and riding style to which the ESA motors are transplanted from your current shocks. Cost was about £1200 ride in ride out at Revs racing in Halesowen. Worth it? Not sure except when the bike is fully loaded with pillion and a months worth of gear and camping stuff when the difference really shows. It may be i over stated weight or that the compromise between solo riding and fully loaded is biased towards loaded.

There’s a few places that will service your standard shocks but as they aren’t really serviceable this means drilling into them to tap a valve so they can be re-gassed. Good results are reported however at around £150 per shock. Note it’s only the shocks that are serviced not the esa gubbins.

Subsequent to the Wilbers being fitted I had an esa motor problem - front preload motor failed. It took ages to diagnose during which time I learned more about bmw shocks and esa than I ever wanted to. Three BMW dealers couldn’t pinpoint the fault including one who wanted to put a whole new ECU on the bike. Beware the dealers is my view, all they ever seem to want to do is throw expensive parts at faults. My fault was fixed with the generous help of a couple of forum members who loaned good shocks so I could test and once confident it was the front preload motor it was just a case of buying one of the loaner and getting the motors swapped over - not easy as they are held on by the spring so you need a spring compressor.

By the way an “esa calibration” is simply using the diagnostic computer to run the esa motor through its range. It can be done with a gs911. The calibration simply winds the esa motor back to its stop, then through to its other stop while counting the number of turns of the motor to do this. It then knows where 10%, 50% and 90% are. The stepper motors can eventually lose their way. It takes all of 5 minutes but doesn’t prove anything, although there maybe more features on a proper BMW diagnostic tool.


Long ramble about my problems but as they relate to you I would say the damping in your shocks has gone and you should consider replacement.

BMW dealer prob not best option for a couple of reasons - shocks are non-serviceable in factory config so dealer won't give you this option. WIll be replace or nothing. Also, they aren't suited to telling you if shock needs servicing as they don't have experience of doing this.

Start off by setting it up correctly, then ride the bike and see hwo it feels. You could take a new GS out on a test ride from a dealer to get some back to back comparison - if there are slight diffs on same road, then no worries, but if suspension feels very different that will give you a good idea. Next step would be to have rear shock serviced for £150ish.

If there are any other forum members or friends near you with similar bike and new suspension you could always try that as way of comparing. But either way I suspect this is something you will need to get a handle on rather than listening to someone else (although a suspension specialist might be a good option if there is one near you).

is your bike a GS or a GSA?

Only on a GSA can you adjust pre-load on the front (GS doesn't have a motor on the front shock-check).

And, as far as I'm aware, the pre-load on the front on a GSA only increases from the standard position when you select the off-road settings....i.e. the preload is the same for rider, rider+luggage and rider+pillion.

Damping adjustment occurs front and back on GS and GSA models.