Fork rebuild and rear shock replacement???

[poggor]

I am rebuilding 82 r65ls forks
I note a picture of a bump stop rubber at the bottom of the rod- this isn't in any of the books and i dont think there was one in my forks? can anyone confirm that the order of these things is correct as i have it?
the larger clearish nylon bush was supplied to me by a parts shop- in the clymer manual it looks like a metal part (black and white pic). there was no equivalent when I disassembled.  thanks!

[poggor]

here is the pic from clymer with the part im unsure about pointed to with a blue pen

[georgesgiralt]

Hello,
The part you point with your pencil and the white plastic bushing are the same.
Once it has been made in a kind of rubber and dissolved slowly in the fork oil in a goo. Then they made it in a red rubber which dissolved itself on the shelf during storage. Some dealers replace it with a kind of nylon bushing originally made for /5 bikes.
So if your's is quite hard it is the /5 part (but will do perfectly) and if it is another material altogether it is because they have replaced the red rubber by anything else...
HAve a nice day.
P.S. if you search this site you'll find picture of the black goo and of the failed red rubber.

[Barry]

I've had those new plastic topping out bump stops fitted for nerly 10 years and they have been fine. You have everything in the correct order.

[ged in oz]

That’s weird. I started rebuilding my 83 R65 forks yesterday as well and had exactly the same thing! No bump stop bush at all and no residue from a disintegrated bush.

I guess the forks work fine without them (sort of), and at some point in time somebody has changed the seals and oil, cleaned everything up and reassembled without the bush.

At least your parts supplier kitted you up with the bushes. I had new seals on hand but I’m waiting on the bushes to turn up now.

[Tony Smith]

All things being equal - i.e all damper piston rods present and in good order and the fork will hydraulically lock before the bumper stop is troubled. for many years when the stop was either NLA or the only one on offer was the disintegrating red rubber stop, a lot of people, myself included, didn't bother with one.

[poggor]

thanks very much for your help everyone- looks like it will be good with the bush in.
however i have some problems- one of the sets of piston rings has become stretched and deformed and bind in the tube and then one of them falls off. I also think i need a fine shim at the bottom.

but i can't find these parts anywhere- does anyone know where i can source them?

g

[Barry]

They are just shims. I made my own but the parts are still available from BMW. What gap did you measure ?   

       07 11 9932656      Shim      22X30X0,1                  
      07 11 9932657      Shim      22X30X0,2                        
      07 11 9932659      Shim      22X30X0,3            
      07 11 9932660      Shim      22X30X0,5

Not sure of the part number for the rings but BMW should have them.  If rings are really not available anywhere and there is enough meat on the piston, what I would do is have a the damper piston slot turned out wider on a lathe to accept the later one piece plastic piston ring. I know this has been done on other model forks and it was a good mod which reduced piston ring friction.

Try Motobins for better prices.

                        

[georgesgiralt]

Look at the picture attached. Buy only one set per side.
Hope this helps

[poggor]

georges- thank you for replying. I have looked at this part number, many of the places selling it list this part as being for other models, but not r65. have you experience with this part? does it actually fit the r65?

thanks a lot for your help

[georgesgiralt]

Yes it does ;-) I've a couple on my '82 ...
In fact all are the same. They forgot to add it to the R65 fiche.

[poggor]

merci mon pote!