Loose front end after heavy braking

[jamestnewsonr65]

The other day whilst riding in London traffic I had to brake sharply (Front wheel locked up, brakes definitely work which is comforting) and afterwards there was something which just didn't seem right.

I checked the bike over the day after and found the top nut was loose on the steering head as well as the item marked as number 15 (Knirled nut) in this parts diagram. http://www.realoem.com/bmw/enUS/showparts?id=0359-EUR-12-1981-248-BMW-R65LS&diagId=31_0296

I've always found this part difficult to tighten as the notches on mine are worn from owners trying to tighten it.

Does anyone know if there is an alternative part which can be used which is easier to tighten?

[montmil]

James, After removing the large Allen screw on top -and it usually takes an extension on the wrench as it should be torqued to spec- that knurled ring/nut will be used to snug up the steering head bearings. Be sure to loosen the top pinch bolts so the triple tree can have some movement.

If the knurled ring is boogered up, you can't do any worse than using a large pair of slip joint pliers. With the bike on centerstand, snug the bearings until it takes just a light push on the handlebars to get the forks to full slowly to the stops.

If necessary, tap the triple clamp down and refit the large Allen screw. Tighten the pinch bolts, too.

Now, move the handlebars slowly through their full arc. If you feel any notchiness... it may be time for new bearings top n' bottom.

[Barry]

I've always found this part difficult to tighten as the notches on mine are worn from owners trying to tighten it.

Does anyone know if there is an alternative part which can be used which is easier to tighten?
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Truth is that knurled nut is a bit of a poor effort on our bikes even when new. Other air heads have the notches for a  C spanner.  I wonder if one of those will fit or alternatively you could cut some notches in your existing ring.

Interesting that heavy braking produced that slack. Perhaps the bearings had never been fully seated.

As Monte said that Allen cap screw has a very high torque spec and they can be a real bear to undo.  Do yourself or some future owner a favour and put a trace of antiseize under cap as the large surface area is a significant contributor to them being difficult if any corrosion gets in between the surfaces.

[jamestnewsonr65]

The bearings were new when I built the bike so I hope they would still be ok after about 300 miles.

I did see a different type of nut on the motobins site that has the notches out of it like you mentioned Barry. I might try one of those and see if they fit, as it seems a much better option.

I'll also check all the bolts on the forks to make sure they are all correctly torqued and snug.

Thanks for the replies.

[montmil]

The bearings were new when I built the bike so I hope they would still be ok after about 300 miles.

Ah ha! Newly installed bearings, you say? Couple tech articles, and I recall a repair manual, include instructions to re-check bearing preload after about one hundred miles of riding. Your replacement head stock bearings may not have been fully seated. Doesn't take more than an RCH of slack to create your concern. Snug 'em up and I'd bet the problem will be fixed.

[Jeremy R65]

Another tactic I have used on my Velocettes to loosen or tighten a lock ring is to use a jubilee clip.  Clamp the Jubilee clip around the outside of the knurled ring as tight as you can, positioning the worm tightening screw where you can get at it to tighten/loosen and, more importantly, where you can hit it with a hammer, either directly or with a drift.  Worked for me.  Jeremy  

[nhmaf]

I think that Monte hit the nail on the head.  Any bearings with axial loads, such as steering head bearings and even swingarm pivot bearings need to 'bed in' and what may have seemed properly tight upon initial install becomes overly loose after 100 miles or so, possibly less depending upon bumps&shocks to the system.

With any luck, you've caught this soon enough to readjust things without anything becoming distorted/abnormally worn to cause any harm.   Snug them back up to the tightness as Monte indicates - just a slight push off from center to get them to smoothly fall on their own to left and right stops.   If they fall too fast, or still seem to have play, snug them up a small amount more.    Make sure that your cables (throttle, clutch) aren't affecting your evaluation of bearing tightness.

[jamestnewsonr65]

Finally got around to looking into this and found the bearings to be pretty loose. Seems the design of the lock ring is really crap on the early 80's 65's and difficult to tighten.

In the end I took to making some marks in the ring so that I could use a hammer and drift to knock it round.

It is much better now and fully seated. Thanks for the pointers and help. On to the next problem!