Infra's 1993 R100GS Maintenance and Improvement Thread

[Infracaninophile]

Originally Posted by advNZer?

tom your measurements suggest to me that there is a significant lip at the inner edge of the "wiped" surface.Is that the case?

Do you mean on the rotor? If so, yes. Until I mount the forks and caliper again I won't be able to see where the pads touch the rotor to see if indeed the issue is that the last 1" or so of the outer edge of the rotor is not swept by the pads.

Tom

[Infracaninophile]

So I torched it today....




And when heat failed to remove the bearing I got serious with Mr. Dremel..




Update on removing steering head bearings in the works.

Tom

[RecycledRS]

Regarding the difference in the inside and outside rotor measurements, could be that there is more material on the outside to wear away (greater diameter) and that is why the it has not worn as much as the inside? Just a thought. Bill.

[advNZer?]

Originally Posted by Infracaninophile

Do you mean on the rotor? If so, yes. Until I mount the forks and caliper again I won't be able to see where the pads touch the rotor to see if indeed the issue is that the last 1" or so of the outer edge of the rotor is not swept by the pads.

Tom

yes on the rotor.If the rotor has worn as much as you r measurements suggest(compared to the new one,i would have expected the very outside edge of the rotor to be around 5 mm.That does not seem to be the case so there must be a lip on the inside edge of the swept area(rotor)

[Infracaninophile]

While the forks were off I decided to freshen my steering head bearings. The parts are relatively cheap and I don't want to have to take the whole front of my bike apart again just to get to them. Got out the Clymer's manual and with some basic hand tools had the first phase done quickly.

Here is the parts fiche for that area. I will remove parts 1, 2,3, 4 and 7 in Phase I.




My forks have already been removed. So, I started today with removing the handlebars. Which BTW look pretty crappy but not gonna do any cosmetic work on the bike until the fall.






Bolts all loose and ready to go...






I laid a towel over the top of the frame and carefully set the bars on it. My front master cylinder reservoir is already empty as I will be replacing my front brake line when done. With a bit of care I was easily able to keep all of the cables, wires, etc.. on the bars and just set them aside. I did remove the little wire loom keeper piece on the front of the top triple so the cables could move around. I was afraid I'd have to remove cables and such and this was not the case.










Next up was to remove this large nut..








Decided to use the air impact wrench. Good choice here when removing.






Now it's time to remove the top triple clamp. Mine wasn't too excited to leave the scene. It appeared to lack cooperation.




At first I tried to play nice. I shot it with some WD-40 to soften it up.




It was still not cooperating and eventually I had to use a small ball peen hammer and tap it about 20 times alternating left and right until it inched up a bit. My guess is that it had never been removed and was a little rusted in place. I did not hit it hard, more of a "tap left, tap right, look, tap left..." until it came off.




Once it was out of the way I could see the "knurled knob" better. I am not sure what caused the weird look on this. I promise I didn't use the torch on it. Looks like rust. Hmmm.




At this point I removed the large nut at the top and set it aside. It has very fine threads. I haven't read that far forward but I think this is used later to adjust the new bearings as they go in. Maybe not.






I then unscrewed the knurled knob. I was very careful as the lower triple tree will likely want to fall out when I was removing the big knob.




Here is an upside down view of the big knob. The upper bearing is stuck onto it right now. I'll worry about that later.




Here's the steering stem sticking out of the top. I did not want to screw up those threads.




Now you can lower the steering stem and lower triple tree out of the bottom of the steering head. Mine just sort of fell out easily. I won't worry about that bearing yet.






With all of that removed here is what you see from the top. The outer bearing race is still stuck in there. I'll deal with those in Phase II.




And a similar view from the bottom.








Phase I was pretty easy even though I had never done this before. Next up is removing the old outer bearing races.

Tom

[robsmoto]

In the exploded drawing above (# 3656) there is an aluminum cup which fits between the bearing and the lower triple clamp. That aluminum cup is shown as item #6. I replace this when replacing the steering bearings as it is usually damaged during the bearing removal process.

I have had sucess in heating the lower triple clamp and then pressing the steel tube (on which the bearing is fitted) out. It is then a simple matter to press the bearing off the tube. The lower triple clamp is reheated (to about 100 degC) and the steel tube is pressed back into place - one should take care to maintain the same angular position of the steel tube with respect to the lower triple clamp. Otherwise the steering lock mechanism will not work. NOTE: some airhead gurus have advocated NOT pressing the steel tube from the lower triple clamp as the fit may be compromised. [In which case the destructive removal of the bearing with a dremel grinding wheel is likely the best option.]

Ed Korn of Cycle Works developed some clever and fairly inexpensive tools for removal of the bearing races. Cycle Works is now under new ownership, but the tooling is still available.

[GJUNKY]

There are 2 holes in the top bearing adjuster that are used to push the bearing off the adjuster. Just use 2 pins the same length in the holes and a piece aluminum across the 2 pins and push the bearing off.

[Infracaninophile]

Originally Posted by robsmoto

In the exploded drawing above (# 3656) there is an aluminum cup which fits between the bearing and the lower triple clamp. That aluminum cup is shown as item #6. I replace this when replacing the steering bearings as it is usually damaged during the bearing removal process.

I have had sucess in heating the lower triple clamp and then pressing the steel tube (on which the bearing is fitted) out. It is then a simple matter to press the bearing off the tube. The lower triple clamp is reheated (to about 100 degC) and the steel tube is pressed back into place - one should take care to maintain the same angular position of the steel tube with respect to the lower triple clamp. Otherwise the steering lock mechanism will not work. NOTE: some airhead gurus have advocated NOT pressing the steel tube from the lower triple clamp as the fit may be compromised. [In which case the destructive removal of the bearing with a dremel grinding wheel is likely the best option.]

Ed Korn of Cycle Works developed some clever and fairly inexpensive tools for removal of the bearing races. Cycle Works is now under new ownership, but the tooling is still available.

Rob:

Thank you for the input. Yes, I have 2 new cups on hand. I also have the tool that Jeff Trapp (JTWind) now sells and used it here. My next post will show how I used the tool and whether it worked or not.

Tom

[Infracaninophile]

Originally Posted by GJUNKY

There are 2 holes in the top bearing adjuster that are used to push the bearing off the adjuster. Just use 2 pins the same length in the holes and a piece aluminum across the 2 pins and push the bearing off.

GJ:

Tried that w/o success. I will have a post by later this evening showing what the status is.

Tom

[Infracaninophile]

Phase II was my attempt to remove the outer bearing races. I admit to doing a lot of research on this in advance and recalling that a lot of folks have problems with it. It seems it's a bit of a reach to get a tool up the steering stem in order to knock the races out. But, there are special tools available that are made by Old Skool inmates.

But first I have to admit that my knowledge of the bearing "parts" was pretty limited. I had handled wheel bearings before as I've cleaned and replaced the ones on various motorcycle trailers, etc. So I was confused by the whole concept of a separate outer "race". All the bearings I've worked on before were just one piece. On a trailer wheel, the bearings just come out after removing the nuts and such. What is a bearing "race"?

Per Wiki: "The races of a rolling-element bearing are what the rolling-elements ride on. The large race that goes into a bore is called the outer race, and the small race that the shaft rides in is called the inner race."

On my 1993 R100GS, my steering head bearings are tapered roller bearings. Their size is 28X52X16. Which I think means the inner opening is 28mm (about 1.1"), the outer diameter is 52mm (about 2") and the depth is 16mm (about 2/3"). They look sort of like this:




The difference here is that the outer race can be separated from the rest of the bearing. After removing the rest of the top and bottom bearings during Phase I, both of the outer races were still in the steering head. My goal was to remove them.

Introducing the main character of this phase: JTWind's special tool:






I had to read Jeff's instructions about 25 times until the concept sank into my head. Part of this was I didn't want to mess up my bike's frame somehow. Part of it was Jeff used a 2 dimensional drawing and words to describe the process. I had to convert that into a 3 dimensional reality before beginning.

Here's what I did:

1. The tool comes with 6 pieces as you can see in the photo above. The copper ring is not part of the tool to remove the races. That will get used later.

2. You assemble 3 of the pieces initially to get prepared. The tool will look like this:



3. The concept is that you assemble the first three pieces and then tap that into the steering head. The split washer will slip under the outer race as it sits in the frame. You then tighten the big nut down which applies pressure and causes the split ring to expand. This locks it under the outer race very tightly.

In the picture below the end pointing to the right is the part that gets inserted first. Then you see the split ring which has a taper. That ring has a split in it. The lock nut is then applied.




It's important to get this side of the nut in first. It allows the split ring to be forced up on the cone at the end.




This picture shows the outer bearing race in the steering head and you can see the gap underneath it. The split ring fits into this space once the tool is inserted.




With the first three parts of the tool inserted into the top of the steering head it will look just like the picture below. I have inserted the first pieces into the head, tapped the end of the threaded piece carefully, and the split washer has slipped under the bearing race. I then used an adjustable wrench on top and a socket from the bottom to tighter the big nut as tight as possible.






The next step is to add this little metal spacer on top.




Then this big flat washer.




And finally the other large nut.




The idea here is to now turn the large nut with a wrench. It will force the outer race up and out of it's current position.




And, if you do it right, it does work. In the picture below you can see the outer race has been removed and it sitting inside the tool parts.




Here's a shot of the tool assembled on the lower steering head as well:




And success again at the bottom:




So, now that I understand how it works, and how bearings work, it seems simple. However, it didn't seem that way up front. I might be the only person who doesn't understand these kinds of things.

I had a few problems with the tool:

1. When installing the first 3 pieces I wasn't tapping the end of the threaded rod and therefore the split ring wasn't lodging itself underneath the race correctly. What I learned to do was to thread the 2nd large nut onto the end of the rod and then tap it lightly with a hammer. It then quickly went into place.

2. You have to use a socket with a long extension and a ratchet that fits over the small end of the big bolt. This end showing in the picture. And at the same time some sort of wrench or socket at the other end. It is crucial that the big nut be very tight onto the split washer to expand it. I finally understood the directions once I'd done it. This was my issue.




3. The last issue I had, and Jeff mentions it in his instruction sheet, is that this spacer has to be situated precisely on the steering head. If not, when you apply the wrench to the big nut the outer race does not come out of it's place as it hits the edge of this spacer. I had to try multiple times to get it just right. But once it was exactly in the right place it works like a charm. Again, Jeff mentions this in the instructions but I had to learn this lesson the hard way.




Here is a shot of both of the old outer bearing races:



Here's a shot of my upper steering head with the race out prior to me cleaning the area. It was pretty nasty.




These things were not coming out easily. My bike is 16 years old and my guess is these are original. They were kind of stuck in there and not going to budge. Very glad to have had JT's tool. It's not expensive and worked great.

Link to Jeff's Site HERE

If I had to do this again for myself or someone else I could have both races out in < 5 minutes.

Next up: Phase III: Removing the old bearings....

Tom

[Airhead Wrangler]

Originally Posted by Infracaninophile

Very glad to have had JT's tool. It's not expensive and worked great.
Tom

+1 on that. That thing has saved me quite a bit of pain and suffering during not one but two steering head bearing replacements this winter.

[Infracaninophile]

Phase III was a pain in the ass. I was trying to remove the old bearings in preparation to installing new ones. But, as expected, the old ones just didn't want to come off. I don't have a press at home so I can't do the press method on the lower steering stem.

At first I tried some heat on the upper bearing. I used a torch and carefully tried to just heat the bearing and not any of the other parts. I tried to pry the old bearing off with punches via the two holes at the top. Nothing worked.

Here I tried to tap the bearing loose from the top via the two holes in the knurled knob. No go.




Then heat. No go.






Then I watched that video with the British guys in the garage. Decided to just dremel them off.


Top:












Bottom:














The old bearings were marked "Germany" and "FAG". The new ones are "Germany" and "SKF".

Lessons learned: Bearings are made out of hard metal. No shit! A good multi-speed dremel tool and a stack of cutting bits will cut it easily. Be careful. I nicked my lower triple tree lightly a few times. Nothing but cosmetics but if I did it again I would not drink beer while doing it.

At this point I am preparing for Phase IV: New bearings.

Tom

[robsmoto]

Originally Posted by Infracaninophile

....Lessons learned: Bearings are made out of hard metal. ....if I did it again I would not drink MUCH beer while doing it....

fixed

[Infracaninophile]

Phase IV is getting ready for Friday at 10 MT when Matt Parkhouse is going to visit my house and instruct me on how to do a few things.

In preparation for this I got some cleaning done and the new bearings ready to do.

First, put the new outer races in the freezer. Matt says we will just heat the headstock with a torch and they should pop right in. Uh huh.




Next I cleaned the area around the lower bearing place




Then slid a new metal "ring" into place.






Then slid a new bearing down to rest there until tomorrow. Not sure exactly how this is going to fit. We can't heat the new bearing too much. I know Matt is going to bring a piece of pipe and I have one as well.






I then cleaned up the upper piece and got it ready.




Got a new metal ring for this end also




And just parked a new bearing there to wait until tomorrow.






Got some good new grease




This is the BMW part number I received for the steering head bearings. It is not the part number on the fiche. Chicago BMW says its the right part. I hope so.




Here is the data from the top of the bearing in case anyone wants to match the part number elsewhere.




I wanted to see what the diameter of the upper piece of metal is where the upper bearing goes over it. It is 28 mm.




The problem is that the new bearing isn't 28mm. It's a tad less which I guess is normal.






So either the bearings have to be heated or some good beating has to happen for them to fit. Because a 27.92mm opening isn't going to fit over a 28mm piece of metal very easily. Not sure if decent heat can expand that to 28.01mm or so.

All ready for Matt in the morning. I am sure he's done this 5000 times before.




If we have time, I'd like to get the forks all the way back on, set the tension at the top, and do a few more things while he's here. I am paying by the hour and he's making a house call. He lives 5 min away. I am very glad to have him.

Tom

PS: Rode the R80 for an hour today. Fun.

[MacMan]

Upside down Miss Jane... A world of pain awaits!