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Impact drivers are great in many cases but, at the end of the day, there are situations that won't succumb to any reasonable force whether it be from a breaker bar or an impact driver if the corrosion is bad enough. Once you get to that point, it's a choice of whether you sacrifice the fastener or ditch the bike. The 'saving grace' of course is that when you get to that point, even if you do manage to get the fastener loose, it's probably not a good idea to re-use it anyway.

The only other technique I've used, which I learned while volunteering in a steam railway workshop (and the corrosion you get around steam locomotives is on a totally different order of magnitude!!!) is a mixture of 'sweating' and leverage. Take the longest breaker bar you can source with a good quality socket. Apply leverage then use a good sized hammer against the side of the bar near the socket. The weight of the hammer is more important than the strength used to strike. Definitely a method of last resort and I'm not even sure it would be very easy to apply in this location but it almost invariably shifts something. Not sure I would even want to try it on the steering head.

Rob

Here's a thought. The cap screw holds the top yoke hard down on top of the the bearing adjuster ring. If there is any play in the steering bearings than theoretically the adjuster ring could be tightened which will move it slightly away from the top yoke. That's a tall order because the adjuster ring is simply straight knurled on the outer edge and it's difficult to get a grip of at the best of times never mind when it under compression from the top yoke. I've thought of drilling radial holes in the edge so that a rod could be inserted to provide leverage. Anyway to get to the point, if the adjuster ring could be moved away from the underside of the top yoke then the top yoke could then be tapped down away from the cap screw. That would release the stiction between the underside of cap screw and the top yoke leaving only the thread to free off. It's a very tall order trying to move the adjuster ring but it might work if there is a lot of slack in the bearings. You will of course need to loosen the top yoke stanchion clamps before attempting to move the top yoke but that will need doing anyway to adjust the bearings. I wouldn't leave the stanchion clamps loose while attempting to slacken of the cap screw because there is enough risk of twisting the forks out of alignment as it is.

Hi all,

thanks for all the useful responses. To recap on a couple of things. I have tried an impact wrench. It's rated at 215n.M (~158ft.lb) and has successfully undone bolts that I know are tightened to ~160n.M. Since the forks/front wheel/fairing and screen are already off, riding it to a workshop is a little impractical. In hindsight I should have checked this bolt first before doing other things. Needed to get the rest off for wheel bearings, brake lines, etc. I'll know for next time. I've tried freeze spray with no success so far. @gspd. Yes I've undone plently of seizes components. I have quality tools (Kinchrome/SP) including impact sockets but I have put a big bend in one socket handle already. I'ves used heat but perhaps not tot he extent you suggest. There are new bolts available https://www.flatracer.com/flatracer-bmw ... lt-w-badge but could probably source something from a fastener supply store. Clearance under than handlebars will be the issue. @barryh - that had occurred to me to. Turning the bike upside is a little impractical. I'll try the preload adjuster idea which is a good call. It's knurled not a hex head so I don't want to ruin this as well.

Cheers,
Rob

Hi All,

status update!! Success at last. So the sequence of things today was... freeze spray, straight way hit it with the impact wrench (no movement) then got my new 600mm breaker bar, locked the steering head in place with a 3x2 piece of timber against my hip, and leaned as hard as I could on a bar. It came loose. As an ex powerlifter there was a fair bit of grunting. Observations - no corrosion under the head of the bolt. Significant corrosion on the threads that hold it in place. No ingress of penetrating fluid into the union.

Lessons learned:
Be patient
Ask smart people for ideas
Assemble with antiseize and use rubber plugs in both ends of the yoke
There is little substitute for leverage

Thanks to everyone for their ideas and conversation. It's greatly appreciated.

Result !

You really must be an ex power lifter to get it done with only a 2 ft breaker bar. I had a length of steel tube on the end to make it 4ft and it was still a struggle.

Good result... I have a metre long breaker bar for this sort of situation. Worth it's weight in gold. The biggest danger is that it can turn the head off a 12mm 8.8 bolt is the thread really won't give...

Rob

Thanks Barry and Rob. I had a 1 metre 3/4 drive on standby from a friend of mine if all failed. So glad it came undone. Now the yoke is out I can easily see why I had some wobbles. Bearings and races very badly worn with old sticky grease, any not much of it. Should clean up OK though. Next challenge is getting the bearing cups out of the steering head.

ozR65LS wrote: ↑Thu Dec 09, 2021 5:02 pm Thanks Barry and Rob. I had a 1 metre 3/4 drive on standby from a friend of mine if all failed. So glad it came undone. Now the yoke is out I can easily see why I had some wobbles. Bearings and races very badly worn with old sticky grease, any not much of it. Should clean up OK though. Next challenge is getting the bearing cups out of the steering head.

The 'easy' way is to run a bead of weld around the bearing face of the race. It will then be loose and can be lifted out without diffculty. But that requires access to a welder. If that can't be arranged, then an expanding bearing puller like the BMW tool is about the only realistic way to do it.

Rob

Thanks Rob. My largest expanding bearing puller is slightly too small so I'll chase a bigger one. I've read elsewhere that a dremel tool to put a cut in the cup and then chisel it out sometimes works. Sounds a bit rough but it worked on the bottom bearing on the stem. Pulled apart the cage and put a cut in the inner race then 1 whack with a chisel was enough to loosen it to remove from the stem.

update on the inner races on the R65LS steering head. They came out after lots of sweating, swearing, and banging with a hammer. The bottom one had a small lip I could get at so after searching without success for a larger puller I went and chatted to my local bike mechanic. He suggested making a drift from a long bolt, which actually didn't work but inspired the solution. The bolt I had had a flanged head on it. The flange was just thin enough to enable me to line it up with the lip. I fitted a couple of nuts to the threaded end to give me something bigger to hit and after about 15 minutes of hitting and slipping it finally worked loose. Once out I could see why it was stuck. Lots of rust between the inside face of the bearing recess and the outside of the race. As for the top, there was no usable lip so I cut a slot in the race to fit the flange of the nut in, then used the same idea from the bottom. Success!! A little bit of cleaning up to remove a few rough edges and I'll be ready to install the new bearings, reassemble, and test ride. Thanks to everyone who offered ideas and I hope my solutions help someone else some day.