Mysterious pulsing issue.

Cheetah

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Hi all.
I have a 2018 GSA which has developed a worsening bump/ rhythmic pulse/throbbing between 65kph and 90kph. It is in no way subtle. It seems predominant in 4th gear but also noticeable in 3rd and 5th. Completely gone in 6th. Disappears when off throttle. The dealer is working with me but even after warranty replacement of both wheels, gear box and drive shaft it’s still there. This speed is right in the sweet spot for commuting and back roads so a real head wrecker and ruining the bike for me. I drove two other GSAs today- an ‘18 belonging to my brother and a ‘17 of a friend. The ‘17 was as smooth as silk but the ‘18 (which has also had both wheels replaced due to the spokes issue) had a definite though lighter version of the pulse/throb. Expect that to develop just like mine. (Brother now jinxed!). Have being riding boxers for 16 years and never had anything like this before. Just wondering if anybody has experienced similar and found a cause/solution before heading back to the dealer again.
Thanks. Jim
 
i think you should press the dealer, and BMW directly, to buy the bike back - either a refund for the unfixable junk they sold you, or they should take it back (and destroy it in a crusher) and put you on a new bike. You did not get what you paid for, they cannot eliminate its problem, and they need to make you whole. Try to get a free initial consultation with an attorney if you can, you are being unjustly screwed and are BMW's and your dealer's victim at this point. They both have profited at your loss.

Please keep us posted.
 
WTF??!

Feeling a little extreme this morning? Perhaps the salesman who sold it should also be cut from throat to scrotum & have his entrails left out steaming in the morning sun?

Perhaps the Op could do exactly as he has & try to identify the issue before coming up with a solution with the brand/dealer?
 
Jim, my GSA Rallye seems to have the same, but not as bad as yours.

it’s my first GS and I ride it with spirit, but the symptoms you mention are there in the background. I have had five RTs and they were fine.
 
Posted a year or so about this on my 2018 model GSA, it isn't as severe on mine and only shows up at constant speeds when the bike is being ridden with the alloy panniers on (ie on Autobahns).

Difficult to describe as on mine it is a pulsing noise like the noise of a V1 pulse jet motor and there is just the slightest feeling of the final drive pulsing .

It feels like some kind of harmonic vibration, dealers unable to find anything and it is undetectable most of the time , I have learnt to live with mine but would suggest with yours you ask that someone from BMW technical try the bike out
 
Ummm. Do you get a high frequency buzz through the pegs as well?(mainly left). I’d put it down to tyres but I’ve changed those and it’s still there.
 
My 14 gs has it at a specific speed when on a constant throttle. Touch the throttle and it stops until you cruise for a few seconds again. I think it’s fueling simply because the lightest of touches on the throttle stops it even if the speed doesn’t change. Partly why I I’m interested to try a hilltopped bike to see how it rides with corrected afr and whether it’s gone. Not interested in the dyno figures etc, just that.
It’s a distraction more than anything but one I would like gone.
 
I may be way off the mark here. I had a similar problem on my ancient R1100GS. The throttles were out of balance causing
one cylinder to get more fuel than the other.
My problem was worse in the lower rev range. Not sure how your higher tech bike fuels, but it could be food for thought.
Good luck.
 
I get the same thing in 3rd and 4th gear with mine. Thought that it might be related to a misaligned shaft at the front end (rear of engine) so had the dealership check it out as they said that very occasionally these can be slightly mis-aligned from the factory (!), but it was given a clean bill of health. I was given the explanation "some do it and some don't do it but it's nothing to worry about". The bike has about 16K miles on it and nothing else is amiss, so I forget about it now and just ride the thing, putting it down to "boxer charm"! With mine it's a slight vibration felt through the pegs which seems to rhythmically cycle unless the bike is on gas or on the over-run, and it happens from about 2.5K revs to 3.5K revs before clearing. Could be something as simple as a slight imbalance in the final drive shaft but as there's no simple way of testing and balancing these, your only option if it's really bad would be to drop another replacement shaft in (an expensive fix and even then, it may not actually be the problem).
 
I had it on a '14 GS, started at 8,000mls, it could be felt as a 'rythmic thrumming' between 2750 and 4000rpm in 4th and to a lesser degree in 3rd. This vibration and the awful gearbox was enough for me to get rid of it against a '17 model with the better gearbox, I still have the 'thrumming' on this one as well, nowhere near as bad though.
 
Sounds like a driveshaft with a sticky UJ problem to me, so I was surprised to find replacement didn't fix the issue for the OP.
http://www.realoem.com/bmw/enUS/sho...8-K51-BMW-R_1200_GS_Adve_0A42_&diagId=33_1709

Are you sure they changed out the shaft & didn't just check if it looked OK? These issues often get confusing when warranty is involved - see if you can get the dealer to clarify & check their screen yourself.
Then again I am confused as to quite how BMW authorised the wheels & gearbox TBH, seems an unusual approach for the mothership.
 
Thanks everyone for the input. Definitely some similarities there. Fueling occurred to me but am assured by the dealer that this fully checked out. I could probably convince myself to live with it but having come off a flawless ‘16 RS it’s hard to accept that a brand newer and later model bike is not actually better. I’ll pursue it further and update how it goes. Cheers.
 
Cheetah, are you riding with BMW panniers ?

If you do...

I know it’s a very long shot, but worth trying without, and not top box. They are a metal to metal connection and just giant sound boxes.
 
When my bike started doing it the dealer greased the splines on FD, this did make a small improvement. I now get the to regrease each service.
 
Every LC GS I’ve owned has done this, worse with a GSA and aluminium luggage and pulse can be clearly felt through footpegs. To me it’s not the fuelling because loading the throttle lightly has no effect. My answer was not to lug the bike around at lower speeds in a higher gear (e.g. 40mph in 4th or 5th, 50mph in 5th or 6th) and rev it a bit more. Sounds better, too :thumb
 
Matty589 said:
Every LC GS I’ve owned has done this, worse with a GSA and aluminium luggage and pulse can be clearly felt through footpegs. To me it’s not the fuelling because loading the throttle lightly has no effect. My answer was not to lug the bike around at lower speeds in a higher gear (e.g. 40mph in 4th or 5th, 50mph in 5th or 6th) and rev it a bit more. Sounds better, too :thumb
Click to expand...

Same here.

I'll drop the drive shaft out and inspect/regrease it but from everyone's feedback this does seem to be very common. Not sure if we're being very fair though as it's not as bad as with say a chain drive with a few sticky links or tight spots. My Triumph Explorer was way better...buttery smooth at any revs in any gear. If BMW have been in the game longer than most others with shaft drive then I'm surprised that they still can't get things like this sorted. To counter that, the bikes are so good to ride in every other area that we perhaps notice when little things detract from the perfect package (does that exist?)...ie we're spoilt.
 
squibb34 said:
Sounds like a driveshaft with a sticky UJ problem to me, so I was surprised to find replacement didn't fix the issue for the OP.
http://www.realoem.com/bmw/enUS/sho...8-K51-BMW-R_1200_GS_Adve_0A42_&diagId=33_1709

Are you sure they changed out the shaft & didn't just check if it looked OK? These issues often get confusing when warranty is involved - see if you can get the dealer to clarify & check their screen yourself.
Then again I am confused as to quite how BMW authorised the wheels & gearbox TBH, seems an unusual approach for the mothership.
Click to expand...

I have the same on a 2014 GSA LC. My local (ex) BMW guy has diagnosed it as a sticky UJ but until they strip and replace we won't be sure.
 
Hi

My 18 plate GSA has started doing this at about 60mph and is ok 5-10mph either side . However it did not do it with the o/e anakees only since I had the dealer put new Tourance nexts on. hmm , dunno, ill get the dealer to check
but think it may just be tyre related, maybe needs balancing ?
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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