• Does any body know the weight of the HD/screaming eagle heavy fork oil, & is that a good upgrade from the stock oil.? My buddy with a streetglide says I want 7.5 weight.....I dont realy know.!

 

Less than one minute using google, I found this:

Type "E" is 5 weight - the lightest one

Type "B" is 10 weight

Type "screamin' eagle" is 15 weight

Type "screamin' eagle racing oil" is 20 weight ( Not intended for street bikes)

 

Just changed to the SE 15 wt. and am satisfied - no more bottoming out on the front end, not even over speed bumps!

 

I wouldn't take those number as accurate. I've seen lots of guesses by people and they vary a lot.

A couple of years ago I was frustrated with Harley for not publishing the viscosity of their fork oils on the product or in the literature. So I sent them an email asking for clarification. After weeks I got a reply saying they don't do it because its more complicated that stating a single 'weight'. That their oil performs differently under different conditions and also that its best to stick to the stock oil.

Not too helpful seeing as every other fork oil maker manages to give a number that is helpful for comparison. So since then I have used BelRay fork oil, which is expensive but at least you know what you are getting. For my Fat Bob I have 15W and that feels just right.

Be wary of using too heavy oil as it tends to make the front end skittish and the handling weird.

 

Harley S/E is 15 weight.

 

Prove it

 

The answer to this question seems to be a better kept secret that the Col. Sanders recipe. I asked this question on here quite some time ago, and although there is lots of good info in the thread, it never got answered definitively.
https://www.hdforums.com/forum/frame...fferences.html

 

Well actually, Foxster's correct.

You can use the "15" wt name to indicate a heavier oil than a "10 wt." and a "5 wt." and so on. So a "15" flows more readily than a "20." ( You could also use #5,4,3,2, and 1, Or Extra Heavy, Heavy, Medium and Light nomenclature.)

How fork oil flows relative to another oil at a given temperature is more to the point.

The Screamin' Eagle flows in the "15/Heavy" category.

There are fork oil flow charts on Google showing the rate of flow at 40*C vs 100*C to give a relative "weight" as compared to other available oils.

 

I'm presently using SE "Performance Fork Oil-Heavy" Part # 99881-87. The label on the back offers no info regarding the actual weight of the oil, other than to say "contains viscosity stabilizing additives" and "not intended for street use." I find the front end to be more controlled and less mushy compared to the stock fork oil, while still allowing for a decent ride. So whatever the weight, the SE fork oil seems to work just fine in my case.
~

 

https://www.amsoil.com/storefront/stm.aspx This with a set of Progressive springs took the dive out of my Fatbob, it's nice and firm now.