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#996254 - 09/06/17 02:57 PM Help - High Frequency Vibration  
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MontanaBud Offline
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2004 R1150RT @ 120k mi. (all mine).

Please help. I've recently developed a high frequency vibration at highway speeds, felt primarily in the handle bars, but it seems engine related (note: this is NOT the usual boxer buzziness).

I've checked the valve clearances, and spark plug gaps (replaced with new 6k mi ago). The problem become apparent after the engine is fully heated. The declutch method at highway speed eliminates the vibration.

I've swapped the fairly new (also 6k mi ago) Beru coils for an old set, but no difference noted. The air filter is fairly new, and clean.

The problem appeared after I installed a new set of tires, but I've rebalanced them, and even replaced the front tire with the old one, and no difference noted. So the timing of this development with the tire change seems coincidental.

Is it possible one of the injectors is clogged, causing fueling imbalance? I'd recently run Techron through several tanks of fuel for a different reason and also to keep the fuel system clean, so a clogged injector seems unlikely (unless it's a mechanical failure of an injector?).

Any suggestion on what is causing the vibration will be greatly appreciated!

#996256 - 09/06/17 03:02 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Originally Posted By: MontanaBud
2004 R1150RT @ 120k mi. (all mine).

Please help. I've recently developed a high frequency vibration at highway speeds, felt primarily in the handle bars, but it seems engine related (note: this is NOT the usual boxer buzziness).

I've checked the valve clearances, and spark plug gaps (replaced with new 6k mi ago). The problem become apparent after the engine is fully heated. The declutch method at highway speed eliminates the vibration.

I've swapped the fairly new (also 6k mi ago) Beru coils for an old set, but no difference noted. The air filter is fairly new, and clean.

The problem appeared after I installed a new set of tires, but I've rebalanced them, and even replaced the front tire with the old one, and no difference noted. So the timing of this development with the tire change seems coincidental.

Is it possible one of the injectors is clogged, causing fueling imbalance? I'd recently run Techron through several tanks of fuel for a different reason and also to keep the fuel system clean, so a clogged injector seems unlikely (unless it's a mechanical failure of an injector?).

Any suggestion on what is causing the vibration will be greatly appreciated!


Afternoon MontanaBud

What road speed?

What engine RPM range?

What transmission gear range (all or only high gear?)

Is it there both hot & cold?

Is it still there IF you ride out to way above the speed range then de-clutch & coast back down through the effected road speed?

Only in the handlebars or in the seat, foot pegs, & handlebars?


D.R. ___
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#996257 - 09/06/17 03:13 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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Road speed: 70-100 mph. Once going down a long steep hill I thought I had sped out of the vibration, but in another attempt it did not.

RPMs: 4000 - 5000.

What transmission gear range (all or only high gear?): I'd say only high gear, but the lower gears are always extra buzzy, so it's difficult to say it's present in the lower gears.

Is it there both hot & cold: Does not appear in the first 10 miles or so of riding.

Is it still there IF you ride out to way above the speed range then de-clutch & coast back down through the effected road speed? NO.

Only in the handlebars or in the seat, foot pegs, & handlebars? Most obviously felt in the handlebars, but also in seat and footpegs.

I also did the motronic relearn, for no reason except somebody here said that worked for them. It made no difference for me.

Last edited by MontanaBud; 09/06/17 03:29 PM.
#996258 - 09/06/17 03:21 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Originally Posted By: MontanaBud

Is it still there IF you ride out to way above the speed range then de-clutch & coast back down through the effected road speed? Yes.



mmmm. Maybe not the motor/tranny. Back tire, perhaps?


-Mike
'08 GSA
"If I don't like it, I'm not blaming myself!"
K. Greiff
"Anything worth doing is worth overdoing."
M. Jagger
#996259 - 09/06/17 03:30 PM Re: Help - High Frequency Vibration [Re: greiffster]  
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Sorry, meant to answer that it is not present after declutching. Fixed it in my answer.

#996260 - 09/06/17 03:37 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Originally Posted By: MontanaBud
Is it still there IF you ride out to way above the speed range then de-clutch & coast back down through the effected road speed? Yes.


Afternoon MontanaBud

This in itself points to not engine related so the 4000 - 5000 RPM's should only be because that is what the engine needs to get that road speed.

Because you call it a buzz & not a shake or vibration that points to higher frequency than wheel speed so should not be a wheel balance problem.

Assuming the coast down observation is accurate then you are probably looking at the pinion side of the final drive, or the output side of the transmission, or drive shaft/U joint area.

If you re-ride it & find the disturbance IS strictly engine RPM related (only) then post back as an engine related buzz requires a different troubleshooting approach.


D.R. ___
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#996261 - 09/06/17 03:40 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Originally Posted By: MontanaBud
Sorry, meant to answer that it is not present after declutching. Fixed it in my answer.


Afternoon MontanaBud

OK, NOW, that statement does put it on the engine side of the drivetrain disturbance!

That is a bit more difficult to find & isolate.

If definitely engine related & in the 4-5K range that is smack dab in the middle of the normal boxer buzz range.

So that sort of points us to a normal boxer buzz that is amplified by SOMETHING. Like loose engine attaching fasteners, exhaust system grounding out to center stand, or to something anyhow, clutch issues, loose transmission attachments.

In any case 4-5K is usually well above the normal influence of injector problems or minor sparking issues (at 4-5 K it is usually all mechanical.

First thing to try is to normally ride out to a moderate speed in high gear, then play with the clutch lever to lightly feather the clutch engagement (lever in & out across the engagement point while applying light normal throttle). This s-h-o-u-l-d allow the clutch disk to self-center on the trans input shaft splines. (IF) this makes the buzz better (even a little) then suspect you have a clutch disk or spline wear issue coming on.

A clutch disk not completely centering on the input shaft will be enough out of balance at 4-5K to really cause a noticeable buzz in the handlebars)

Otherwise check the exhaust system for being bent, loose, or contacting something other than the mounts.

Also check all the engine & transmission bolts for being tight.

One last thing to try-- if your oil level it at top of sight glass then try draining some out to put oil level at or below midpoint.

Lots more to try but the above should be enough to get you stared or hopefully point us in a direction to go after.

Last edited by dirtrider; 09/06/17 03:53 PM.

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#996269 - 09/06/17 06:23 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Two places I've found for vibrating wierdness:

Muffler mount at the left rear - If the rubber bushing is failing you can get metal on metal contact and the resulting vibration.

I'm not sure about the R1150RT, but on the R1150RS, when the rubber up stop bumper fails on the center stand, it can bump into the bottom of the muffler (cat chamber area) and transmit vibration. If you loosened the muffler when you removed the wheel, you may also be able to twist the muffler assembly enough to cause contact with the center stand.


1995 R1100RSL
#996271 - 09/06/17 07:41 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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I removed all Tupperware and bags and went for a ride. The vibration seemed present immediately upon reaching speed (whereas I had previously found it only upon reaching full operating temp). I tried feathering the clutch, but felt no real change in the vibes.

Before the ride I checked all the bolts at the footplates. All tight. Everything seems in order (except a bolt missing from the lift handle, so I replaced it). I don't know about other mounting bolts. Anything to look for under the gas tank?

I checked the center stand. The rubber bumper is present, but during the ride I pushed down the center stand slightly with my heel and there was no change.

I examined the exterior of the muffler, but no signs of anything amiss there. I didn't loosen it when removing the rear tire.

The oil level is center of the sight glass.
Very frustrating! I needs to ride.

Last edited by MontanaBud; 09/06/17 07:44 PM.
#996274 - 09/06/17 07:49 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Originally Posted By: MontanaBud
I removed all Tupperware and bags and went for a ride. The vibration seemed present immediately upon reaching speed (whereas I had previously found it only upon reaching full operating temp). I tried feathering the clutch, but felt no real change in the vibes.

Before the ride I checked all the bolts at the footplates. All tight. Everything seems in order (except a bolt missing from the lift handle, so I replaced it). I don't know about other mounting bolts. Anything to look for under the gas tank?

I checked the center stand. The rubber bumper is present, but during the ride I pushed down the center stand slightly with my heel and there was no change.

I examined the exterior of the muffler, but no signs of anything amiss there. I didn't loosen it when removing the rear tire.

Very frustrating! I needs to ride.


Afternoon MontanaBud

Those high speed higher RPM buzz type problems are very difficult to diagnose while riding the bike & ever more difficult over the internet.

Have you tried an engine revv to the 4-5K RPM range while sitting still (trans in neutral)? --If so what do you feel?

How about riding at 4-5K in 1st, 2nd, 3rd, 4th? Do you still get the buzz at 4-5K?

Where is your engine oil level?


D.R. ___
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#996276 - 09/06/17 08:09 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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I just revved the bike in neutral to 4k to 5k rpms, and there is considerable vibration all over including at the handlebars.

I do run the revs up to that range when riding up to highway speeds, but I don't think I can sense the vibration because the bike is normally full of vibrations in those gears. Only when I hit 6th does the bike (normally) smooth out.

Oil level is at the center of the sight glass.

What about the possibility that the stick coils are failing (already)? Spark is not an issue at those rpms?

#996278 - 09/06/17 08:21 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Originally Posted By: MontanaBud
I just revved the bike in neutral to 4k to 5k rpms, and there is considerable vibration all over including at the handlebars.

I do run the revs up to that range when riding up to highway speeds, but I don't think I can sense the vibration because the bike is normally full of vibrations in those gears. Only when I hit 6th does the bike (normally) smooth out.

Oil level is at the center of the sight glass.

What about the possibility that the stick coils are failing (already)? Spark is not an issue at those rpms?


Afternoon MontanaBud

Your 4-5K buzz isn't stick coils, TB balance, vacuum leaks-- At 4-5K under road load it is MECHANICAL.

If you have a bad coil, TB balance issue, or other engine fueling/sparking issue it will be twice as bad at 2K as it is at 4-5K so if you are somewhat clean at 2K the it (IS) MECHANICAL.

I see that you have had this issue for about 60,000 miles & over 8 years now so it obviously isn't something new or just cropped up___ http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=637877&page=1

You might just have a bike where all the original balance tolerances were built at the outer ends of spec.

My guess is that given the length of time that the problem has been with you, & the fact that the engine hasn't self destructed yet, that your problem is a combination of normal boxer buzz coupled with an out of balance crankshaft or poorly balanced clutch assembly. Or possibly a set of pistons that are not properly matched at original assembly. (ie, something mechanical anyhow)


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#996279 - 09/06/17 08:27 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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I have had a similar issue in the past, but it was finally resolved. This is new.

#996281 - 09/06/17 08:32 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Originally Posted By: MontanaBud
I have had a similar issue in the past, but it was finally resolved. This is new.


Afternoon MontanaBud

What resolved it last time?


D.R. ___
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#996282 - 09/06/17 08:38 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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A misaligned footplate, caused by yours truly, after it was removed for.... what was I doing. Anyway, I tweeked it off balance and caused the opposite side footplate to touch the transmission.

I have checked for that same thing this time, but I see no contact, nor do I know how that could have suddenly cropped up when nothing was done other than a tire change.

#996283 - 09/06/17 08:53 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Originally Posted By: MontanaBud
A misaligned footplate, caused by yours truly, after it was removed for.... what was I doing. Anyway, I tweeked it off balance and caused the opposite side footplate to touch the transmission.

I have checked for that same thing this time, but I see no contact, nor do I know how that could have suddenly cropped up when nothing was done other than a tire change.


Evening MontanaBud

If you ONLY did a tire change & your present problem cropped up right after the tire change then it should be easy to find.

Go back over every bolt that you removed or moved during the tire change, look for anything moved or bent by whatever you used to hold the bike up. Look for the exhaust system to be back EXACTLY where it was before the tire change.

If you are definitely getting a buzz (not a shake or vibration) then whatever is causing it is spinning at least two to three times wheel speed. So that is engine, trans, or input side of final drive.

It could be just a normal boxer buzz that is amplified or transmitted by something touching the active drive train that wasn't touching before the tire change.


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#996313 - 09/07/17 02:55 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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I had this happen once and found the driveshaft needed replacing because of a loose (worn)joint.
Felt it most on highway deceleration.94 R1100RS @ 77k

#996337 - 09/07/17 10:02 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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Originally Posted By: dirtrider
Evening MontanaBud

If you are definitely getting a buzz (not a shake or vibration) then whatever is causing it is spinning at least two to three times wheel speed. So that is engine, trans, or input side of final drive.


As DR and Marc C have suggested, maybe there is a problem with the input side of the final drive? I did replace the drive shaft two years and 15K miles ago. Four years and 48K miles ago, the dealership installed a used final drive unit that had 23K miles on it, but installed a new crown bearing.

Someone down the road suggested a possible pinion bearing going bad. Would it be worth pulling the FD, and if so, what do I look for?

#996340 - 09/07/17 10:43 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Bud -

Have you considered oil analysis? Not guaranteed to show anything but if it does, you know what to persue.


Channeling farfegnugen since 2011.
#996348 - 09/07/17 11:53 PM Re: Help - High Frequency Vibration [Re: TheOtherLee]  
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Originally Posted By: TheOtherLee
Bud -

Have you considered oil analysis? Not guaranteed to show anything but if it does, you know what to persue.


Analysis of the FD oil? Or engine oil? I've not considered it, but will. Unfortunately, I just changed those fluids, so will need to give it some more miles.

What could such analysis tell me?

#996349 - 09/07/17 11:56 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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This may be nothing out of the ordinary, but I did just put the bike on the center stand, started the engine, and put it in 1st and slowly let out the clutch. I heard a clatter in the lower end of the swing arm. The clatter disappeared when I twisted the throttle slightly.

Anything telling here?

#996361 - 09/08/17 12:34 AM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Bud -
Drained into a CLEAN pan, oil can show glitter, feel gritty. Chemical analysis can show wear in specific materials - see here for example. Blackstone Labs will give a good laymans interpretation of the results - so you don't have to be a chemical engineer to understand them.

Magnetic drain plugs can be helpful. Beemer Boneyard has 'em.

Last edited by TheOtherLee; 09/08/17 12:46 AM.

Channeling farfegnugen since 2011.
#996362 - 09/08/17 12:46 AM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Originally Posted By: MontanaBud
This may be nothing out of the ordinary, but I did just put the bike on the center stand, started the engine, and put it in 1st and slowly let out the clutch. I heard a clatter in the lower end of the swing arm. The clatter disappeared when I twisted the throttle slightly.

Anything telling here?



Evening MontanaBud

Normal, basically just a stack up of 2 cylinder low RPM harsh firing pulses, extended drive shaft angle, & no wheel loading.


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#996382 - 09/08/17 03:35 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Originally Posted By: MontanaBud

I examined the exterior of the muffler, but no signs of anything amiss there. I didn't loosen it when removing the rear tire.


If you didn't loosen it, you surely bumped it a bit with the tire along the way. As you re-trace your steps, I'd remove the muffler hanger from the subframe (bolted from the inside) and from the pin on the muffler (clip at the end of the pin) to examine the bushing which rides on the pin and make sure it isn't damaged. No guarantee that it is part of the problem, but it is quick, easy and cheap to fix or rule out.


1995 R1100RSL
#996400 - 09/08/17 07:48 PM Re: Help - High Frequency Vibration [Re: rxcrider]  
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Originally Posted By: rxcrider
Originally Posted By: MontanaBud

I examined the exterior of the muffler, but no signs of anything amiss there. I didn't loosen it when removing the rear tire.


If you didn't loosen it, you surely bumped it a bit with the tire along the way. As you re-trace your steps, I'd remove the muffler hanger from the subframe (bolted from the inside) and from the pin on the muffler (clip at the end of the pin) to examine the bushing which rides on the pin and make sure it isn't damaged. No guarantee that it is part of the problem, but it is quick, easy and cheap to fix or rule out.


Okay, I removed the rear wheel, and pulled the bushing from the pin on the muffler. The bolt was a bit loose, but the bushing looked fine. I cleaned up the rubber bushing and lined it with a 5mm latex glove finger, reinstalled everything and went for another ride. Sorry to report, no change.

I think I do feel the buzz a bit more in the right hand than the left, but this handsander-like buzz seems to exist throughout.

Argh!

#996651 - 09/11/17 09:23 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Would bar backs or the risers exaggerate this issue ?
mark

#996653 - 09/11/17 10:17 PM Re: Help - High Frequency Vibration [Re: Dobo]  
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Originally Posted By: Dobo
Would bar backs or the risers exaggerate this issue ?
mark


Evening mark

They can sure effect it, depends on how it effects/changes the excitation periods. Might make it worse, but could just as easily make it better.

On the 1200 hexhead I actually remove the 4th handlebar attachment bolt (only use 3) then space the bars up on very thin stainless washers to provide a tuned hinge point. That tuning coupled with heavier bar end weights changes the tuning enough to allow most of the boxer buzz to dissipate & not get to my hands.


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#997821 - 09/26/17 05:13 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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Originally Posted By: dirtrider
Originally Posted By: Dobo
Would bar backs or the risers exaggerate this issue ?
mark


Evening mark

They can sure effect it, depends on how it effects/changes the excitation periods. Might make it worse, but could just as easily make it better.

On the 1200 hexhead I actually remove the 4th handlebar attachment bolt (only use 3) then space the bars up on very thin stainless washers to provide a tuned hinge point. That tuning coupled with heavier bar end weights changes the tuning enough to allow most of the boxer buzz to dissipate & not get to my hands.



that's interesting i cut up 2 3mm rubber pads to sandwich between the risers etc and it made no decernable difference.
will try your fix.
cheers mark

#997881 - 09/27/17 08:40 AM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Hi Dodo, I feel uncomfortable with sandwiching rubber in that application. Those bolts need to be tight.
It sounds like you are trying to deal with a resonant vibration. If you cant fix the source of the vibration (say, for instance loose bolts or some mechanical parts touching each other that shouldn't be - like an exhaust mount against the frame), then maybe playing around with handlebar end weights may be worth some investigation. There are some high mass end weights available.

#997886 - 09/27/17 11:18 AM Re: Help - High Frequency Vibration [Re: Dobo]  
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Originally Posted By: Dobo
Originally Posted By: dirtrider
Originally Posted By: Dobo
Would bar backs or the risers exaggerate this issue ?
mark


Evening mark

They can sure effect it, depends on how it effects/changes the excitation periods. Might make it worse, but could just as easily make it better.

On the 1200 hexhead I actually remove the 4th handlebar attachment bolt (only use 3) then space the bars up on very thin stainless washers to provide a tuned hinge point. That tuning coupled with heavier bar end weights changes the tuning enough to allow most of the boxer buzz to dissipate & not get to my hands.



that's interesting i cut up 2 3mm rubber pads to sandwich between the risers etc and it made no decernable difference.
will try your fix.
cheers mark


Morning Mark

I doubt that you are going to isolate it out & still retain a safe connection so you are probably going to have to tune or absorb it out best possible.

The boxer engine buzz it what it is so not much you can change on that.

To turn the bars into tuned absorbers you will probably need to play with bar end weight & bar excitation frequency. (ie add flex to bar attachment & add mass to end of bars)-- If the triple tree is buzzing but the bar ends are dead then you know it is working as a tuned absorber)

Buy some strips of stick on wheel weights & wrap those around the existing bar end weights to see if you can work up a mass on the bar ends that is enough to help. Use that in conjunction with different iterations of 3 bolt bar attachment on thin washers. If you get something working then weigh the new bar end weights then see if you can make or buy something in a similar weight.

On some of my dirt bikes (known for very buzzy bars) I foam fill the center of the tubular bars then add lead bird shot to the outer ends to deaden the buzz. Works pretty darn good but not easily done on the BMW RT bikes.


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#997977 - 09/28/17 08:57 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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thanks guys , i will have a look for fittings etc transmitting the buzz,
good advise about tuning the bar ends with sticky weights .
will give it a try .i have some lead tape from my golfing days.
cheers Mark

#999309 - 10/19/17 06:49 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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Very quickly read the thread... What tyres did you have fitted? Ive experienced harmonic resonance vibration problems in the past- most noticeably with the Avon Azarros STs.
Seems you missed one critical detail in your first post- the tyres..?

#999311 - 10/19/17 07:06 PM Re: Help - High Frequency Vibration [Re: japachap]  
Joined: Jun 2010
Posts: 13,196
dirtrider Offline
The Oracle
dirtrider  Offline
The Oracle
Member

Joined: Jun 2010
Posts: 13,196
Ohio
Originally Posted by japachap
Very quickly read the thread... What tyres did you have fitted? Ive experienced harmonic resonance vibration problems in the past- most noticeably with the Avon Azarros STs.
Seems you missed one critical detail in your first post- the tyres..?


Afternoon japachap

You need to put more effort into reading these threads.


First page 3rd reply down--- Is it still there IF you ride out to way above the speed range then de-clutch & coast back down through the effected road speed? Answer NO.

That eliminates the tires & wheels.


D.R. ___
Sent from my rotory dial wall phone!
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