Steve Saunders Goldwing Forums banner

21 - 36 of 36 Posts

·
Registered
Joined
·
1,410 Posts
Discussion Starter #21
Got the one back on,used 320 cc of oil,when I get the solder,bushings it will all come back down and maybe drill the top,this time I just added the oil through the bottom bolt in the fork.
 

·
Registered
Joined
·
653 Posts
I've never understood the logic of using a heavier (15W) oil in the forks when installing heavier (progressive) springs. Seems to me, you'd want a lighter oil to help reduce the stiffness of the heavier springs. I still have the OEM springs in mine (as far as I know), based on the tendency to dive on short stops. I use the 10W, and 10psi air in the front, and am really happy with the ride I get. Very smooth, and the dive is mitigated by the 10psi air.
 

·
Registered
Joined
·
1,410 Posts
Discussion Starter #24
I've never understood the logic of using a heavier (15W) oil in the forks when installing heavier (progressive) springs. Seems to me, you'd want a lighter oil to help reduce the stiffness of the heavier springs. I still have the OEM springs in mine (as far as I know), based on the tendency to dive on short stops. I use the 10W, and 10psi air in the front, and am really happy with the ride I get. Very smooth, and the dive is mitigated by the 10psi air.
I understand what you are saying,one would need to know what Honda used as a guide as to the amount of oil,a 120 rider? No Rider,put the fork on a machine?
Something I found searching oil level,the air cavity above the oil seems to be the item that causes the shock to work proper and not the oil 100%.That seems to explain why when the seal leaks it gives the air a path of least resistance and causing loss of air resulting in bottoming of the fork,it will still have oil in it but will eventually blow out?
The more oil ,less air and it's a ruff ride,less oil,bigger air to compress,softer ride?
 

·
Administrator
Joined
·
24,504 Posts
The more oil ,less air and it's a ruff ride,less oil,bigger air to compress,softer ride?
I agree, I always leave my oil level at least 1/2" lower than the given spec.
 

·
Registered
Joined
·
1,410 Posts
Discussion Starter #26
Was reading this article and realized I been thinking wrong on how forks work.Motorcycle Fork Oil:
Let’s Get Technical!
Good motorcycle fork oil has some basic requirements: viscosity must be suitable, high viscosity index, good anti foaming agents and good lubrication properties. Most leading oil manufacturers of quality suspension oil will meet those requirements.



But the best fork oil won’t help you when you ride with the wrong oil level. And believe it or not there are some crazy oaks out there who just change the oil level without really knowing what the effect will be. Almighty crashes can be the result.

Remember that the relationship between oil level and progression is not linear but exponential. In other words: adding 20ml more oil may not make a huge difference the first time. Add another 20ml and you may suddenly find the fork becomes very hard deeper in the stroke.

Double the amount of oil does not double the air pressure relationship. It increases it to an exponent of around 2.6 times. Your fork becomes harder and harder as it compresses the more oil you add. But the initial fork stroke remains similar. If you add too much oil your fork will become very uncomfortable and hard as it compresses.


The graph shows the effect of adding oil. The initial part of the fork stroke is not affected too much in both examples.



As pressure builds up in the fork with the smaller air volume (higher oil level) it gets much more progressive than the fork with the larger air volume (lower oil level).

So feel free to experiment with oil volume, but stick within the maximum and minimum levels in your manual. If you experiment make 10ml changes at a time in order to feel the effect. Be warned you may find your fork suddenly becomes way too hard if you add a little too much fork oil.

The safest and probably best thing to do is to use standard oil level. This has been carefully worked out to match the damping and springs in your fork. No, not all engineers in the motorcycle industry are ninkumpupses. They actually know what they are doing!




Top of page
Return from MOTORCYCLE FORK OIL to SUSPENSION

Return from MOTORCYCLE FORK OIL to DIRT BIKE SECRETS
 

·
Banned
Joined
·
4,568 Posts
It is my belief that Progressive says 15w because they assume Wing riders, and the many other heavy bikes that use the same spring
are carrying a load or 2, and maybe a camping trailer or small Patriot missile launcher
Dealing with Weight Transfer under braking is one of the forks jobs, while responding to bumps.

Note the air limit is 6 psi!! It will take more for a little while then expect to see oil creeping past the seal.
If you need 10 you may need new springs.

Note! You cannot use any of the stock capacity oil numbers with the thicker wire of Prog springs.
Must reduce amount to install by approx 2 ounces, which on the 94, 11 ounces works fine.

Only those with air valve caps can play with oil levels for fun.
Interesting you added thru the drain hole, hey as long as it went in- now drain out the excess 2 ounces!
 

·
Registered
Joined
·
1,410 Posts
Discussion Starter #28
It is my belief that Progressive says 15w because they assume Wing riders, and the many other heavy bikes that use the same spring
are carrying a load or 2, and maybe a camping trailer or small Patriot missile launcher
Dealing with Weight Transfer under braking is one of the forks jobs, while responding to bumps.

Note the air limit is 6 psi!! It will take more for a little while then expect to see oil creeping past the seal.
If you need 10 you may need new springs.

Note! You cannot use any of the stock capacity oil numbers with the thicker wire of Prog springs.
Must reduce amount to install by approx 2 ounces, which on the 94, 11 ounces works fine.

Only those with air valve caps can play with oil levels for fun.
Interesting you added thru the drain hole, hey as long as it went in- now drain out the excess 2 ounces!
I used the big hole in the bottom,the bolt that attaches the slider to the tube for filling,with the fork upside down.
 

·
Administrator
Joined
·
21,895 Posts
It is my belief that Progressive says 15w because they assume Wing riders, and the many other heavy bikes that use the same spring are carrying a load or 2, and maybe a camping trailer or small Patriot missile launcher
Where do you get your 'beliefs'? Do you make it up yourself, or is there a website you can go to called "1001 Tidbits of Misinformation."
 

·
Banned
Joined
·
4,568 Posts
wiki truthiness by Stephen Colbert

some fact, some feeling, and the occasional bit of skewed logic for good measure
I dont know that its true, but I feel that it is

I dont believe the air in the fork is the primary issue, the flow of oil being more control of the action- hence TRAC anti-dive controls the oil flow thru fork.
 

·
Registered
Joined
·
18 Posts
Interesting,from what I read the SE was the only model that had them?
I don't care for them,I only ride single so no need for more pressure on the seal,that is if it does put pressure,my 85LTD had them but I always rode double.
I had a 1990 SE and it did not have that valve in the top.
 

·
Premium Member
Joined
·
721 Posts
I didn't do the first fork seal and Progressive spring change on my 88 after i bought it and they started leaking the following year after i bought it. I believe the GENERIC instructions that came with the springs said to use 15w fork oil so that is what the shop put in. WRONG for my weight.. I called Progressive and they said for my weight of 180# and passenger of ? it should be 10w fork oil. It was much better for me than the 15w. Shop never touched my bike again. Broken and misplaced pieces didn't set well with me. They FORGOT to install new steering bearings while it was all apart. I ended doing that myself and everything else for 10yrs after that.

I think in later years i used less oil also than the standard to ride a little softer and still handled fantastic. I bought caps with the shraeder valves in them from Honda and just had to take the valve out to fill with oil if i changed the oil or had to replace seals again. I used a coat hanger and measured the oil from the top down and worked for me. You have to let it sit quite a while for it to drain down the springs all the way. I just let it sit overnight to make sure.
 

·
Registered
Joined
·
1,410 Posts
Discussion Starter #34
I rode mine today with 320 cc in and liked the way it worked.
 

·
Administrator
Joined
·
24,504 Posts
I rode mine today with 320 cc in and liked the way it worked.
Just changing the fork oil once in a while makes a noticeable difference.
 

·
(Rick Sheeley GWRRA)
Joined
·
659 Posts
...and add Progressive springs while you have them apart (if not already...)
 
21 - 36 of 36 Posts
Top