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knotchy head bearing

Posted: Mon Sep 03, 2012 12:16 am
by anandabandit
So how to decide when to replace a knotchy head bearing

The mechanic says find, not dangerous, very ok to wait - but just know it should be replaced in the next year or so. Anybody have a good test to decide if fixing it (quoted $550) is a good idea?

- Lena

Re: knotchy head bearing

Posted: Mon Sep 03, 2012 12:33 am
by mattcfish
I get worried because my head bearing seems to be immune to knotchiness. I hear about how prone to wear these are but in the 22 years I've owned my /6 I've never had an issue with it. By knotchy, you mean when the bike is on the center stand it doesn't feel smooth when you turn the bars back an forth....right?
With motorcycles, if it has to do with stopping or steering, fix the problem as soon as you determine what it is.
Oh, and don't pay $550. Learn to do it yourself for about $30-$60. Somebody might have a good link about performing the procedure.

Re: knotchy head bearing

Posted: Mon Sep 03, 2012 1:35 am
by Airbear
Lena, that notch affects handling - it is right in the centre, where the delicate business of balance through those critical couple of degrees of movement can lead to a feeling of insecurity. The thing is, it's not really noticeable until it is fixed and you discover just how nicely our airheads handle through the twisties.
If it's only slight, just noticeable when you move the forks through the central position, you could be fine for a little while. Check it each time you ride and you'll notice it getting slowly worse, along with an increasing feeling of insecurity when cornering.
I'd get it fixed fairly soon, but $550 is an outrageous quote. Maybe there is an experienced amateur mechanic near you who could take you through the procedure. There is no reason why you can't do it yourself, but there are some tricks involved - getting the old bearing shells out can be a pain, etc. If you indicate where you are located, a Boxerworks member might happen to be nearby and able to assist. As Matt states, the bearings are not expensive. Good luck.

Re: knotchy head bearing

Posted: Mon Sep 03, 2012 4:32 am
by chasbmw
Sometimes it is not the bearing, but old hard grease, it cam be worth it to clean the existing bearings and regrease, before going down the full replacement route.

Re: knotchy head bearing

Posted: Mon Sep 03, 2012 12:48 pm
by anandabandit
Thanks for the advice - I have yet to ride it and evaluate. Just thought I'd see what the experts say before I head into the dealer. $550 seemed a bit extreme :shock: though I'm sure how involved the quote was. Also, the mechanic said he'd skip the fix.....so.....I'll ride and report. I'm in San Diego, and at the winds of fate as far as pricing goes. If anyone knows someone who'd take on this job (and do it well) for a more reasonable amount - I'd be interested.

Re: knotchy head bearing

Posted: Mon Sep 03, 2012 1:16 pm
by barryh
Cleaning out and replacing 28 year old hard grease 5 years ago sorted mine and the steering is still smooth today. If you want to try something easy as a very temporary measure, see if you can get some oil into the bearings. If the notchiness goes away chances are cleaning out and replacing the old grease will be all that's needed.

Re: knotchy head bearing

Posted: Mon Sep 03, 2012 2:01 pm
by melville
I got my head bearings a couple years ago for ~$80, so I suppose the rest of the $550 is 5ish hours of big city shop time which might be about right for a GS.

If you dare to DIY, the only real holdup for a home job would be removing the outers from the frame head in case it is the bearing and not just the grease that is bad. As the labor commitment is nearly the same for replacement or just greasing, I'm sure they're only quoting a bearing replacement.

I'm from a bicycle background, and bicycles generally use round balls in their head bearings and they notch up (brinnell) quite often. When I saw folks riding and making big corrections from side to side I knew they needed a new headset. Airbear is right on--it is the ability to make the tiniest corrections that is the most important in maintaining balance.

Re: knotchy head bearing

Posted: Mon Sep 03, 2012 2:23 pm
by Deleted User 62
There's a guy on ebay selling head bearing sets for about half of what BMW is asking... FWIW

Re: knotchy head bearing

Posted: Mon Sep 03, 2012 2:38 pm
by Unclviny
I have a set of those NZ-made bearings for my /5 and I need them now (I bought them for spares), the /5 has a "detent" in the center now from sitting in one position for YEARS.

Vince

Re: knotchy head bearing

Posted: Mon Sep 03, 2012 3:00 pm
by Major Softie
Unclviny wrote:I have a set of those NZ-made bearings for my /5 and I need them now (I bought them for spares), the /5 has a "detent" in the center now from sitting in one position for YEARS.

Vince
The bearings don't "detent" from sitting - that would be dried grease. The detents come from repeated pounding in the same spot.