Headlamp shake

scotia_steve

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Just got back from a trip where I finally got to use my lights at night.

My headlights shake, almost judder with road undulations.

Is this normal? 2008 R1200GS, no screen or other mod.
 
If it's your first time out at night you may just be seeing the effect of the normal movement of the bike making the headlight bounce up and down. The headlamp is fairly solidly mounted so it will transmit any bump to the light beam.

If you are used to something much heavier like a car it will take a while to get used to, but it's normally less noticeble at speed.

However, there are a couple of things to check which will can go wrong:

1) Check the bulb is still properly clipped in place - the clip is a naff thing and is very fiddly to set properly. If it's not done right the bulb can fall out of the holder and wobble about.

2) There have been several cases (me included) where the internal reflector has been pushed out of the ball and socket adjusters. It can be easily done when a new bulb is pushed in place as it's cr*p design. If the reflector is loose it will jiggle about and with it the light beam. There's a few threads on how to fix it if it is loose
 
If it's your first time out at night you may just be seeing the effect of the normal movement of the bike making the headlight bounce up and down. The headlamp is fairly solidly mounted so it will transmit any bump to the light beam.

If you are used to something much heavier like a car it will take a while to get used to, but it's normally less noticeble at speed.

However, there are a couple of things to check which will can go wrong:

1) Check the bulb is still properly clipped in place - the clip is a naff thing and is very fiddly to set properly. If it's not done right the bulb can fall out of the holder and wobble about.

2) There have been several cases (me included) where the internal reflector has been pushed out of the ball and socket adjusters. It can be easily done when a new bulb is pushed in place as it's cr*p design. If the reflector is loose it will jiggle about and with it the light beam. There's a few threads on how to fix it if it is loose

The center adjuster flip works (up/down flip) but when you turn the plastic screw it doesn't adjust - I wonder if that's the bit you are speaking about? The screw turns but the headlamp assembly stays put.

The bulbs seem good - first thing I checked and high beam seems to shake just the same.

It's just a proper vibration, most noticeable on motorway signs at night with the light properly shaking on the sign...

Bike has done 5500 miles and is still under warranty so will see what the dealer says when I take it in for its 6k mile service next week.

Part of me wondered if it was the ESA on the blink as there seems to be a lot of small high frequency bumps transmitted.
 
Also check the two mounting bolts near the screen adjusters that hold the whole lot on. When my headlight was bouncing around a few cars started to flash me I discovered one of the bolts had dropped out. :blast :blast
 
Also check the two mounting bolts near the screen adjusters that hold the whole lot on. When my headlight was bouncing around a few cars started to flash me I discovered one of the bolts had dropped out. :blast :blast

First thing I did - Tried them loose and fully done up, no difference made. Must be the headlight....
 
I wonder if that's the bit you are speaking about? The screw turns but the headlamp assembly stays put.


The outer headlamp assembly (the black bit) isn't altered by the adjuster. Instead it's the internal plastic reflector assembly that is moves. If you take off the bulb access cover (and perhaps take a bulb out too) the internal reflector part of the headlamp (including the bit the bulb plugs into) should not move if you wiggle it (don't push it too hard !!!) If it appears loose (like several mm of play in any direction) it's possible it's fallen off the internal tiny ball and socket joints that locate the reflector inside the headlamp assembly that hold it steady but also allow it to move when you turn the adjustor screw. If it has fallen off and it's not due to you fitting a new bulb with a bit too much force, it's something that ought to be fixed on warrenty
 
The outer headlamp assembly (the black bit) isn't altered by the adjuster. Instead it's the internal plastic reflector assembly that is moves. If you take off the bulb access cover (and perhaps take a bulb out too) the internal reflector part of the headlamp (including the bit the bulb plugs into) should not move if you wiggle it (don't push it too hard !!!) If it appears loose (like several mm of play in any direction) it's possible it's fallen off the internal tiny ball and socket joints that locate the reflector inside the headlamp assembly that hold it steady but also allow it to move when you turn the adjustor screw. If it has fallen off and it's not due to you fitting a new bulb with a bit too much force, it's something that ought to be fixed on warrenty

The first thing I did was check the bolts at either side, then take both headlamp round covers off (not bulbs though) and have a look inside to see if anything was loose.

The silver reflector has a few mm of play either side - not loose, just moves slightly of you press it.

I don't think it's ever had a new bulb. Bought it at 2500 miles 2 months ago and never replaced a bulb myself.

Will call the dealer and get them to sort. I thought it might have been something like that!
 
Update:

Just had a good look, doesn't appear loose at all and now I've tried properly, the headlamp adjuster works when turned and flipped.

It seems to be the whole instrument and lamp unit shaking when going along normal roads. Wonder if there is an off chance the ESA is gone and not stopping high frequency stuff as well as it could....

Will get BMW to have a look...
 
I found on my '08 recently that the metal wire clip that holds the bulb for the dipped beam can slip down about 1mm on it's screw mount.

If it does this then the top part of the clip does not fully secure the bulb and means the bulb itself could bounce. the bottom part of the bulb is held firmly.

Solution is to release the clip, then slide it up slightly on it's mount and then re-clip the bulb in.

Not seen this happen with the clip on the main beam which is fitted vertically instead of horizontally
 
I found on my '08 recently that the metal wire clip that holds the bulb for the dipped beam can slip down about 1mm on it's screw mount.

If it does this then the top part of the clip does not fully secure the bulb and means the bulb itself could bounce. the bottom part of the bulb is held firmly.

Solution is to release the clip, then slide it up slightly on it's mount and then re-clip the bulb in.

Not seen this happen with the clip on the main beam which is fitted vertically instead of horizontally

Good tip, just noticed mine was loose at the top following a bulb change, followed your advice and all good.

Thanks,
Phil.
 


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