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Fork oil

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David R

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Sparky3
Ride is too stiff. I looked up the fork oil.
BMW Spec 4.
What weight is that?

I think it’s 20 wt.

I want to try some 15 wt
Also trying to buy an adjustable rear shock from Tourtech.

David
 
I found Spec 2 BMW fork oil is 11.5 wt. I also read BMW says all bikes with sliding fork suspension should have 7.5 wt which I have 2 quarts of.

Ebay <~~~~ Link

This is not the one I want. They come in stage one through four. Stage three uses the original BMW spring adjuster off your bike. Stage four has a remote hydraulic adjuster. Stage one is in the picture. Stage two has external reservoir. I found them on the European tourtech site by accident. When I went to buy it, I could not use USA as a shipping address, so I could not purchase the stage 3 i want.

Stage 3. Remote reservoir, 50 clicks rebound, 30 clicks compression, low speed and High speed adjustments.

I want to keep the factory adjuster because it has almost an inch of travel. I put Ohlins on my R1200R. The external adjuster was so bad, I used the original one on the bike with much better luck.

David
 
Kept looking. R9T takes the same oil as R18. After looking I found R9T takes 7.5 wt. Going out to buy some 5 wt.
David
 
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OK, I have another thread for the rear shock.

I changed the oil to 5 weight in the forks. I took the upper black fork covers off and left them off. That was part of the job.

I replaced what ever was in the forks with 5 wt fork oil and it rides better. Not huge, but noticeable better.
Pics next
David
 
I do agree that it definitely improves the looks for my tastes at least.
 
They are steel, Maybe one KG each. The large dome on top of the fork is solid steel, The cap on the fork is 46? mm diameter and about the same length of solid steel. Crazy weight.

I did it for looks.

Got a date with the misses for breakfast. A better test.

David
 
David R said:
They are steel, Maybe one KG each. The large dome on top of the fork is solid steel, The cap on the fork is 46? mm diameter and about the same length of solid steel. Crazy weight.

I did it for looks.

Got a date with the misses for breakfast. A better test.

David
Click to expand...
Thinking of removal for stripes. How are are they to remove?
 
I had to pull the wheel,
Remove calipers, wrap in rags, set on cylinders
unhook ABS sensor
remove windshield (crazy easy)
Remove BIG locktited bolts holding the forks to the triple tree with a T55 socket. This was difficult. I heated the bolt on the second one.

Loosen lower triple tree bolt and slide fork out. I had to tap and pull.

David
 
Hi David , i am going to change the falk spring and oil. I ve got the tube falk free from the wheel . I am unscewing the tube top screw. It quite hard . Is the Spring in compression there ?
Thank you .
 
20 thousand miles later, I have a leak at the left seal.

$123 EACH from BMW. A "gasket kit"

I also found a set of emulator valves that are supposed to fit.
I will look at item 5 "Set Damper Unit"

Changing the oil DID help with the harsh ride in the front.
It was not the whole answer. I just checked, I used no more than 2.5" of my front suspension according to my zip tie.


The rear shock fixed all the rear problems.

David
 
OK, I should put this in a new thread.

For compression damping, All I could find were 2 holes in the lower tube. NO valve, no spring, no shim stack.

For rebound, Item 5 is built in the base of the fork leg. It has 4 holes (6mm?) outside with steel inserts limiting flow to just a slot in the middle. It has 2 plastic items that move a little. could be just bearings, or part of item #5 because they move. I looked and saw no springs of any kind. So I think its fixed orifice for rebound. Control it with oil viscosity.

For Compression, I did not measure the old holes, but I drilled them out to 8mm. They were probably 6mm. Instructions called for 8 holes 8mm. Too much like swiss cheese, so I opened up the two original and added 4 more. Looked like PLENTY to me. It was more area than the valve had, far more than the diameter of the tube.

I also drilled out 2 more holes in the small cap of the new emulator. It came with one drilled, but I knew for my Gold wing, I drilled them all out.

Now for the test drive.

Noticed before I got out of my gravel yard. small bumps disappear, big bumps are smaller. I went around the block twice. No doubt it rides better. Feels more settled in the corners. It should.

I did get that plush ride from the front. Now the front is softer than the rear.

So I used a YSS PD valve #425.
2 turns on the center spring
10 wt oil
KI drilled out 2 more for total of 3 holes in little blow off cap of new valve.
I cut 25 mm off the spring spacer. Right now I have 20 mm front sag with me on the bike.
Total 6 8mm holes in lower tube.

After a ride, including some HARD braking, my Zip tie is at 3.75"

I had issues with ABS and ran with out it for a while. I found out right away, the linked brakes help keep the front end from diving under braking. It defiantly works. I never new until I rode it with out it.

I fully recommend this mod to your bike.

I have Race Tech valves and springs in my Gold wing, and my R75/6.

David happy Root
23,000 smiles
 
David R said:
20 thousand miles later, I have a leak at the left seal.

$123 EACH from BMW. A "gasket kit"

David
Click to expand...
$123 each for a fork seal gasket kit? Don't you feel that's highway robbery? What does BMW bill to rebuild the left fork leg when the seals start leaking? How much shop time? My 2018 Sport Glide went 5 years and 17k miles before needing a right fork seal. $37 for fork seal. $11 for Maxima 10 wt fork oil, and 2 hrs labor at HD dealership @ $120/ hr in May of 2023. It required a couple of special Harley Davidson tools to do the job.
 
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