The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: ambrose78 on August 13, 2009, 08:54:20 PM
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Well it is coming time to do a fork rebuild -
1 - in an attempt to narrow down the mild wobbling.
2 - One of the tubes is suffering from black oily lines
Having poked around on motobins to try and order some parts, they appear to carry kits for all the r series bikes except the R65/45.
Do any kits exisit? Do the r65's need a kit at all?
Cheers
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There are only 5 parts per fork that are considered 'consumables' on an R65 .
Have never seen a kit before .
At the top plug, there is an o-ring, the large oil seal that fits into the top of the lower fork leg, a plastic bumper inside the damper assembly, a crush washer for the bolt at the bottom of the lower fork leg that holds the damper in place, and a copper crush washer for the drain plug on the backside of the lower fork leg .
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None of the UK suppliers list parts for R65/45. The polyurethane topping out bush is available though not listed for the R45/R65 it fits. Other than that you only need fork seals which are avaialable and maybe the crush washers. If you can't get new crush washers you might get away with anealing them. The washer on the damper rod bolt at the bottom of the fork has to seal well because it keeps the oil in so this has to be reasonably good otherwise any small fibre washer that fits would probably be ok for the drain screws.
What year is your bike ? There were several changes to the damper valve assembly in the early years. If it's a 78 - 80 you may need to shim it. The usual parts fiche sites will show the differences.(http://)
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Last time I cleaned out and added new seals to the 81's forks, I don't recall seeing the nylon (?) bushing pictured in Barry's posting. That has left me in a quandary.
Referring to the A&S diagram:
http://www.ascycles.com/Illustrated_catalog/R65(78-85)/catalog_frameset.html
What item number is the plastic bushing? I need to refresh the seals in the '83 and I'll bet the bushing may be missing in that bike also. Better order four!
Monte
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I think it's reference item # 24 .
I know my bike is missing them, never saw them when I took it apart, and didn't know I needed them until about a year after I rebuilt mine .
If some one can show the proper installation of this part, as my '84 LS needs the forks gone through, and I won't mess it up this time !!!!!
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Yes it's item 24 and fits immediately under the damper piston. In practice you push it into the lower stanchion before inserting the valve plate, valve washer and valve body in that order. Dimensions are 28mm OD 18mm ID and 7.75mm thick. The Motobins replacement was a few thou bigger (sorry for the mixed units but I can't visualise a few thou in fractions of a mm) than 28mm OD so was a slightly tighter fit than the original. The other dimensions are not critical as the bore is 2mm larger than the piston rod and the 7.75mm thickness only affects the fully extended length of the forks when the bikes on the stand.
The original bushes were black rubber so may have disintegrated. Mine were quite brittle.
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The original parts were black rubber, that explains the black goo that was in the forks, when I took them apart .
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I'm going for the Motobins hookup. Thanks, guys, for the solid info. [smiley=thumbsup.gif]
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Cheers for the info.
My bike is a november Build '81.
So are these the correct parts to order?
29020 nylon ring
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fwww.motobins.co.uk%2Flibrary%2F29020.jpg&hash=5aeb97be8abf86c2bf70455b4a8fb8dc75c5c590)
93904 rubber oil seals
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fwww.motobins.co.uk%2Flibrary%2F93904.jpg&hash=1adc4e5848654259678c025169ecdde47903a546)
oring
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fwww.motobins.co.uk%2Flibrary%2F29093.jpg&hash=19e4408a705cb6bf9c446771fc714b4d591c080c)
washer
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fwww.motobins.co.uk%2Flibrary%2F29092.jpg&hash=d4040329ef30c7133ee8c1be80bec6465690fa76)
and a couple of crush washers
I was also thinking about adding some gators to protect the upper seal and stauncions
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fwww.motobins.co.uk%2Flibrary%2F93900.jpg&hash=2756fe7b45ad15717f20e5cbf0be5678dc1adea5)
Cheers
Peter
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The rubber dust cap, that goes over the fork seal area, has a piece of felt that fits into a groove, and acts as a wiper on the fork tube .
The gaiters need a narrow clamp to secure them, a normal cooling system hose clamp won't work, it's too wide .
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Hi Bob,
I don't quite understand what your mean - Does the dust seal come with a felt seal or do I have to order one?
Would the gators work with zip ties?
Cheers
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The felt strip is a separate part, but if you going to install gaiters, the rubber cap comes off, as the gaiter won't fit with it installed .
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Gotcha.
Thanks.
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Pete, This is the "felt" wiper that tucks inside the OEM rubber boot. It's oiled after install in the boot and serves as a dust wiper. With gaiters, the boots and felts are not needed.
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi196.photobucket.com%2Falbums%2Faa1%2Fmontmil%2FBMW%2520R65%2Ffeltphphtml.jpg&hash=f4f9cf614aba73f2e87226451b66c79796dd3c1e)
Don't forget to order the fork "seals". Please confirm all part numbers with Motobins or your agent prior to ordering. Monte
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi196.photobucket.com%2Falbums%2Faa1%2Fmontmil%2FBMW%2520R65%2Fforksealphphtml.jpg&hash=cf1a1f59226038fd86b8b8947c16ed82dc2b88d2)
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Thanks for that Monte,
I will just stick with the felts and boots.
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Pete,
Do order those fork seals and replace them while you have everything apart. They are not that expensive and are pretty easy to replace. If you go for those accordian gaiters, those seals will stay like new and keep that oil on the inside of the sliders for a long time.
John M
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I'm definately getting the fork seals.
so to clarify- the shopping list should read:
*oring
*fork seals
*nylon bush
*fork oil drain washer
*one of the following
- if gators then narrow clip - no boot no seal
- if boot then get the felt seal too
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If you do decide to install gaitors, here is the BMW part number for the metal clamps : 07-12-9-952-121 .
I don't know how long ty-wraps would last, I didn't even consider using them, due to the high heat here in Phoenix, and plastic lives a hard life in these conditions, and the clamps were $1.59US each at the time, so not that costly .
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The original parts were black rubber, that explains the black goo that was in the forks, when I took them apart .
Yes, I too had a crazy amount of black goo in the bottom of mine when I replaced the seals.
I get an annoying "clank" in the front end when I go over an uneven place in the pavement (bugs the hell out of me)....bet that bumper is my problem.
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Has anyone used the progressive springs listed on motobins?
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Has anyone used the progressive springs listed on motobins?
Dont let this steer you away but I have never read a post that anyone has ever said anything but ...."too stiff"....
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Sound like good advice.