The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: quietglow on August 16, 2021, 04:24:32 AM
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So my new-to-me R65 is missing the fork bridge center nut for some odd reason. I have one on order. They are still available new!
The tech FAQ here covering steering bearing replacement/adjustment instruct one to tighten the fork clamp bolts to 30lb BEFORE torqueing down the center nut to 88lb. Is this correct?
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Hello !
The adjusting nut is the curled disk UNDER the upper triple clamp.
As it's action is to allow the upper triple clamp to become closer to the lower triple clamp, you MUST have the fork legs bolting nuts loose for this to happen.
But, once the play set properly, you have to lock properly the fork legs.
And, then, you can lock the securing nut on the center post....
And check again the play... Often locking the nut change the play of the steering.....
So you may have to adjust again the play.....
It is something of a compromise. You have to set the play a little loose in order for it to be spot on when the locking nut is torqued at the proper value....
May I add that you should check and grease the bearings before setting the play ? I bet the nut is missing because the steering was not satisfactory and the PO removed it in order to improve things... Hardened grease can have funny influence on those bearings and on the way the bike handle....
It is a lengthily process but a very satisfactory one, road wise....
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Thanks much George.
So right now the steering feels nice and smooth but maybe a little too loose. There's no movement in the fork, but the bars will flop to the side very (too) easily. It's almost if the person adjusted the bearings just as you described: a little loose so that when the locking nut was added, it would be perfect. They just forgot to put the nut on! Lots of work was done on the bike, so I wouldn't be surprised if that was exactly the story.
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It looks uncomfortably clean in there. Like it's been jetwashed and I don't like the butchers marks on the knurled nut. I think you should get the top yoke off and see what the top bearing looks like before buttoning anything up. If it's dry and rusty, keep going!
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It looks uncomfortably clean in there. Like it's been jetwashed and I don't like the butchers marks on the knurled nut. I think you should get the top yoke off and see what the top bearing looks like before buttoning anything up. If it's dry and rusty, keep going!
Yeah sorta feeling that as well. Also, if I have to take off the dash and tank, might as well right? I got this to tinker, so time to start tinkering.
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Probably not a bad idea on a new to you bike, to check the bearings .
I did a modification about 20 years ago to the steering tube . There are two holes on the front side, they should have plastic plugs installed, if they are not there you need to plug them .
I added 90 degree grease fittings in these holes, filled the whole tube area with grease .
I had to make a tool to prevent the grease from coming out the top hex hole and the bottom end .
I used a length of threaded rod with large rubber grommets and large area washers with nuts to keep the grease where I wanted it .
It was a bit messy, but water will not get to the bearings now .
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So my new-to-me R65 is missing the fork bridge center nut for some odd reason. I have one on order. They are still available new!
The tech FAQ here covering steering bearing replacement/adjustment instruct one to tighten the fork clamp bolts to 30lb BEFORE torqueing down the center nut to 88lb. Is this correct?
Without disagreeing with what others have said I do it slightly differently and I will explain why.
The reason for tightening the fork clamps first is that applying the very high torque to the centre cap screw has the potential to twist the forks out of alignment so you want the clamps tight to resist that. However you don't want any clearance between the underside of the top yoke and the adjuster ring because if there is you will stress the top yoke when the centre cap screw is torqued up. So what I do is lightly tighten the center cap screw first to make sure there is no clearance then tighten the fork clamps and finally fully torque the centre cap screw. I hope you can see the logic in that approach.
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------- just agreeing / commenting -------
RT fairing and Pro RG2 red waterproof grease is my solution to keeping bearings dry. I like the idea of plugging holes and means to insert grease on a naked bike though!
RE: Assembly and tightening. Getting things assembled lightly in their correct places before whaling on the torque wrench is something I've learned to do through various brit and early jap carp bikes. I can confirm that the forks will stick if you don't do this. Bouncing on them after having the front wheel out before doing things up tight is a good idea also.
My guess is very old dry 'burned chicken fat' grease appearance and worn but bright bearings. Could be a dry old rusty mess with cart tracks though. I'm thinking if they are new or good and the PO had some mechanical sympathy, why is the top nut missing?
------- EOT -----------
:lurker:
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- I'm thinking if they are new or good and the PO had some mechanical sympathy, why is the top nut missing?
------- EOT -----------
:lurker:
This is the big mystery to me because there are lots of signs of somebody not cutting corners elsewhere on the bike. Nice new Metzeler tires, new shocks that cost more than the ones I'd have put on there, properly adjusted carbs, steel brake line, rebuilt tach etc. I am brand new to old motorcycles, but I have had lots of experience with coaxing old cars (bmws in particular) out of the grave and back into usefulness. I find that understanding the back story of how the vehicle got to where it is really helps save time when diagnosing problems.
My current guess on this bike is that someone was in the middle of refreshing it and stopped the process suddenly. I have some backstory details to support that theory. So my best guess for the missing top nut is that they were either right in the middle of doing the steering when that stop happened OR they hadn't gotten that far yet. Given the new tires, I'd like to think it was the former, but that assumes more about the POs reasoning that I probably ought to.
In any case, we shall see! I picked up a whole tree assembly from ebay with a better looking adjuster nut. So when that arrives, apart it comes.
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The tree is going to be here much more quickly than I planned, so I decided to go ahead and bust down the front to see what was up. All said, it doesn't seem horrible to me. The grease was old enough that it feels tacky (actually, I think it might be Lucas red n tacky grease), but there was plenty of it. The bearings themselves look good. The races have bright spots but no pitting or groves perceptible to the touch. I think I'll grease it up, put it all together, and ride out the rest of the season. Over the winter when I need a project, if nothing else is looming I'll replace bearings and races. Sound reasonable?
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If they don't feel "notchy" when you get it back together and adjusted why replace them? I have never been one to throw new parts at something just because the old ones had some age on 'em. If that was the case my ol' lady would have replaced me long ago!
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Ah burnt chicken fat scenario. The marks on the outer race, do they wipe off or are they permanent?
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Yeah there was no notchy-ness before I took it apart, so I'm with you Justin. I do think the bearing preload wasn't tight enough, but that's almost certainly because of the missing top nut.
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Without disagreeing with what others have said I do it slightly differently and I will explain why.
The reason for tightening the fork clamps first is that applying the very high torque to the centre cap screw has the potential to twist the forks out of alignment so you want the clamps tight to resist that. However you don't want any clearance between the underside of the top yoke and the adjuster ring because if there is you will stress the top yoke when the centre cap screw is torqued up. So what I do is lightly tighten the center cap screw first to make sure there is no clearance then tighten the fork clamps and finally fully torque the centre cap screw. I hope you can see the logic in that approach.
Thanks Barry, somehow I missed this until now. This seems like a reasonable way of doing it, and it gives me a better understanding of the reasoning behind the order of steps.
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Hello,
On the picture you posted, one can see vertical bars on the outer race in the steering head.
Are those grease marks ? Or are they staying after a wipe ? If they stay, your bearing are shot. Otherwise you can reuse them with fresh new grease.
A visual trace is the testimony the surface has been marred. It is sufficient when it shows.
I use on my desk a paper weight consisting of a used wheel bearing from a BMW front wheel. The outer race is faintly different looking where the rollers rolled. And this made the bearing make a huge noise. And you can't "see" it with your finger .... Roller bearing MUST be pristine and perfect.
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Hello,
On the picture you posted, one can see vertical bars on the outer race in the steering head.
Are those grease marks ? Or are they staying after a wipe ? If they stay, your bearing are shot. Otherwise you can reuse them with fresh new grease.
A visual trace is the testimony the surface has been marred. It is sufficient when it shows.
I use on my desk a paper weight consisting of a used wheel bearing from a BMW front wheel. The outer race is faintly different looking where the rollers rolled. And this made the bearing make a huge noise. And you can't "see" it with your finger .... Roller bearing MUST be pristine and perfect.
Yup, if I put it back together and the steering doesn't perform correctly, I'll definitely replace the bearings.
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If the trace we saw are not stain, you better replace the bearings before putting things back in place... It will save you time and effort.
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Eh, I am not so much worried about time and effort. I bought this bike to wrench on, as my newer bike tends to just work (which is kinda boring). ;D
I noticed no steering issues before I opened it up, so I wouldn't be surprised if there aren't any after putting it back together. I have a local Airheads tech session next month that will be a fine venue to replace the bearings if I am feeling it (I'll bet someone has the snazzy bearing puller).
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You have at least two forum members grumbling about brinneling and galling on roller bearings now we have seen THE MARKS :stare:
Do we have a 'cold stare' smiley? ;D
Or (better) a 'Gandalf the Grey giving Bilbo Baggins a disapproving look' when he says he lost The Ring? :tekst-toppie:
I can't get too exited about head bearings, if it were a wheel bearing I'd be giving it the full "Warning Will Robinson" / "Aliens motion alert" / "AK47 waving" type of stuff.
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Or (better) a 'Gandalf the Grey giving Bilbo Baggins a disapproving look' when he says he lost The Ring?
Bilbo never lost the ring. That is, one might argue, basically the point of the entire story.
cold stare
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Bilbo never lost the ring. That is, one might argue, basically the point of the entire story.
No he gave the ring away and he was the only one that did.
Happen to be reading the book now for the 20th time or more.
Films are a cinematic triumph but as faithful depictions of the book they are complete rubbish and I can't watch them without outrage at the liberties taken. The book creates images in your mind which the films can only destroy because they are someone else's images. There are very few films truly faithful to the classic books they are based on. To kill a Mocking Bird with Gregory Peck is one.
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Going even further completely off topic, I enjoyed The Watch series recently. I guess they spent the whole budget on Detritus in the first episode, but pocket sized flamethrowers that fly and magical projects popping up everywhere has to be a fun watch.
Those bearings do look past their best. I doubt they will lock up or chuck you off, but you may have trouble adjusting (lol!) when the top nut goes back. I think I've spent about 1/3 max of the initial low cost of the bike on various seals, lubricants, bearings and bits and bobs over three years. Which for a 40 year old bike is pretty good. At the moment the market value is about the same as what I spent. Plus I know everything is solid now.
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I'll have to agree, that the bearings are worn .
If you're just riding local no round the world or extended trips, I think they will last for years to come .
Even on those 'challenging ' roads of the Cook county forest preserve district !!!! ;D
If by chance you need any specialty tooling for future jobs on the R65, here's a shop that a lot of tooling just for airheads .
https://www.cycleworks.net/index.php?main_page=contact_us
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Even on those 'challenging ' roads of the Cook county forest preserve district !!!! ;D
You still remember! I'll bet they haven't repaved them since you were here last!
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My new fork nut finally arrived! So I started putting things back together, then realized it would likely make things much easier if I used a proper tool to seat the roller back on the tube. When I started shopping for bearing tools, the wisdom of just replacing the whole bearing began to make more sense. If I'm going to buy the tool, might as well use it. So this kit from Cycle Works is the one people like?
https://www.cycleworks.net/index.php?main_page=product_info&cPath=29_50&products_id=64
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Yes, everything you need. And a couple of new bearings....
You may add the grease cup under the bottom bearing in the order list. Sometimes it is very rusted and sometimes gets ruined during removal of the bearing....