Has anyone tried 10w fork oil, the stuff that HD use's is type "E" witch converts to 20 weight, trying to git rid of the stiff front end ride on my 013 Ultra & thought I'd change the oil first & see how it responds.
Next I'll change the fork springs..
Already changed out the rear shocks..

 

Type E is approx. 38-40cST@40C which is approx. a 11-12wt. compared to leading brands. In other words Type E is a heavy 10wt but is definitely not heavy enough to be considered a 15wt. in any brand.


If you read internet myths it's easy to get confused. Red Line, Bel Ray and Spectro have all shared their findings on Harley fork oil.


When choosing a brand/weight of fork oil it's good to go on that company's website and look up the actual viscosity. IMO the 40C/104F rating is more important than the 100C on cruiser applications.


You can try a 10wt. and see what you think.


With speed sensitive valves like Race Tech emulators you can increase the fork spring rate (to decrease the amount of dive and travel used) and still get a better overall ride compared to stock fixed orifice damper rods, if emulators are properly adjusted along with correct oil viscosity and level.

 

I did the fork oil change yesterday went w/ Bel Ray 10w it makes a difference in smoothing out the ride, now the front end dosen't bounce off the ground it absorbs the bumps..
took the bike out on 25 mi of semi-rough backroads & it did good..
there is no diving under front braking no worse than before..
I was ready to sell this bike..

 

Bel-Ray 10wt fork oil use to be 36cSt@40C, a while back it was changed to 32cSt@40C. Depends on whether you got new or old stock.

 

dunno ??? new old ?? all I know is it works!!! it's better than dawgshit HD uses!!

 

I shared the viscosity of the oils you mentioned or are using. You don't seem to appreciate the info.


The difference in viscosity between Bel-Ray 10wt and Type E isn't really enough to be classified as being a 5wt difference.


Harley oil isn't garbage so it's more likely that the difference, if real, is fresh oil versus used oil...if both oils were fresh then I have no explanation.


By the way did you notice this is posted under "Air Suspensions"?

 

I sure did notice this is posted under air suspensions, that's how all of this got started, all I know is since the fork was changed the bike rides much better.
BTW, the info I have on fork oil weight came from a chart published by Spectro Oils, according to Spectro "E" is 20w..

 

That is a 100C comparison chart...doubt your fork oil that hot (212F).
40C is likely a better reference for street cruisers.