Steering head bearings

Thank you Robert and John for taking the time to think about this.

I don't have a lock stop plate, just lugs on the bottom yoke and a welded on lug in the centre of the steering head tube.

I've been just nipping up the stem nut before inserting the stanchions, then pulling those up with the top nuts so it's pretty much there. It all goes together very smoothly (I've had enough practice now!!) with the stanchions greased and the pinch bolts loose. I don't nip those up until everything is properly in place.. You have to do the stem nut up to draw the bottom yoke into place to capture the headlamp lugs, but it's just finger tight at this stage, or just hand tight with a box spanner with no tommy bar.

Normally I would bounce the forks with the front brake firmly on at this stage to settle everything, but I am a bit reluctant to put fluid in the line just yet until I sort out the proper handlebars. Maybe I should bleed it up and try that anyway.

On the stand with a bit of weight on the seat rails the forks glide from side to side as smooth as a baby's. with the wheel in contact with the ground it moves the freshly powder coated stand feet on my chipboard floor, hence why I tightened up the Iso's in case there was an issue there.

I've been all round the top and bottom yokes with an inspection lamp and feeler gauges to check there is clearance. I did find a witness where the dust cover had cut a groove in the coating on the weld of the steering lock plate. (The lockable one at the top) I ground this out and achieved clearance.. There is no contact between the yokes and frame except via the bearings.

Could do with another straw to clutch!

Thanks Simon, I was actually referring to the brake fluid. The forks have their oil in them and I can feel no play with the stanchions in a vice, leaning on the legs in all directions.

I had no inspiration to go in the shed last night, but I think the only way forward is to fill the brake, give the forks a good pounding on the brake and then tighten everything up. That's always been standard practice for me with anything front end related anyway.

What I don't get is that there's nothing to adjust on this set up. The top and bottom inner races can only be tightened between the yokes and spacer and that's that. The bottom bearing taps in to the bottom shoulder in the steering head tube. The only thing that kind of has to position itself is the top outer race, there is no mechanical location for that other than the bore of the steering head tube, it relies on being tapped into position when it is knocked down onto the spacer, nothing can really effect it once its in place.. I'm thinking as I type that maybe I need to make a "puller" to firmly clamp the two bearings onto the spacer tube before the stem goes in?

Weird though that this only surfaces when the weight is on the front wheel, otherwise the action is ultra smooth.

Thanks for telling me there should be no notchiness Bob. (If that is a word?)

Thank you for engaging with this chaps. I think we might be getting a bit closer now?

I'm going to reply in full to the last posts at lunch time when I have a bit more time and I'm also going to refer back to the factory manual for the n-th time and check the other two manuals I have as well. Cheers.

You had me going there John, by saying the top bearing is pushed home first. That's counter intuitive to me as I would have thought the bottom bearing needs to be up against the end of the housing to take the weight of the bike. Checking the factory manual confirms that it's the bottom bearing that goes in first up to the hilt as it were. The Haynes manual doesn't have anything to say about it, but it does advocate the brake on and bouncing that I should really be doing next.

Steve don't feel stupid for putting the washer on top of the dust cap. The manual says "Place the the top dust cover and washer over the top steering head bearing." Which does imply the order?. But goes on, "Note that the washer fits below the cover". Why not just say fit the washer then the cover?? A bit too late to edit I guess!

So yes my washer is in the right place.

Ian, yes sealed 2rs bearings with spacer. Mine is a mm or 1/32" shorter than spec'ed, but it is still longer than the distance between the bearing housings. The bottom bearing is home and I struggle to know exactly what is meant in the manual by abutting the bearing against the spacer tube. I've had it with the tube still moveable but with the bearing in contact, a bit looser and also driven onto the tube to the extent that it will turn both inner races with the tube turning between. I'm only tapping the outer race at this point. maybe I should be tapping the inner race at the final stage to knock it onto the tube?

I don't believe that the stem nut can draw up the assembly effectively as John noted that the thread is rather coarse. It seems to just make contact and stop rather that continue to tighten. In any case it's rather optimistic to expect the outer race to move when the inner is drawn up with the stem nut, so unless that bearing is in the correct position when installed all the stem nut is doing is pulling the races out of line.. Isn't it?

Why is the tube longer than the distance between the housings? That doesn't make sense to me. Surely the tube should be spot on the same as the housings so every thing fits in line?

I'll get the brake working tonight and give it a good bounce tightening from the top down. If that doesn't work, I might take it down to Cromer and see if it bounces when I push it over the cliff.

Well! As I said that is counter intuitive to my way of thinking and also the manual, but if you say that is the way it is then I will give it a try. Hey ho, what's another front end pull down at the end of the day? I'm quite practiced now. 

That might actually load the bearings the way I want them to go, as bringing the bottom bearing up against the tube should raise the top inner and load it against the outer upwards and the same for the bottom too if I give the final tap on the bottom inner. So there should be equal load bearing on both bearings. All this is subject to the bearings being square of course, which apart from my checks is a bit pot luck really.

It will rob the dust cover of a little more clearance though and that leads me to think that it has never been that low before in this bike as there are no previous witnesses, but then I might just have to get another spacer tube if this doesn't work out.

Looking at the link you posted to the parts illustration,. (the link was not live btw, but I worked out what it was.) It occurred to me that I might possibly have a mixture of 750 and 850 angled yokes. I assume if that was the case that I would not be able to assemble the stanchions in? At the moment they slide up beautifully and centre in the tapers perfectly.

Neither of my yokes have a "ANG" cast in, so I'm safe there. Cheers.

I've got the brake bled and given the front end a good pounding, I've done the sequential tightening and things are a little better. I can eliminate the clunking lock to lock by pushing the forks down hard with the brake on and leaning on the bars, but it comes back when the pressure comes off even just a little.

I think I've cocked up the sequential tightening a bit as the headlamp lugs have come loose a bit.

I nipped the bottom yokes up on the stanchions first and not the stem. I think one final session settling the yokes down and then dealing with the stanchions again should get it sorted, but what a palava!!

Thanks for your help John, I'll update again tomorrow eve.

You should be safe under the Cromer cliffs for the time being.. :-)