Long story short... I have changed my fork oil last year, had a warranty issue with my front fork seals, had them replaced at the dealer, the tech says to me when I picked up the bike.... "the seals are new and we replaced the fork oil while in there" Problem now is I can hear the fork spring "creaking" when I compress the front end, and if feels "mushy".
What kind of oil did they put in there? I previously used the heavy duty HD oil and was happy with the stiffer feel. Question is.. what now, just re-change the oil? Any better oil out there rather that HD ?

 

I tried the SE Heavy in my 11 RKC, hated it. I put the E weight fork oil in, much better. The RK was all over the place with that heavy oil in.

 

I'm using Lucas Syn Fork Oil 10W and like it better than the stock HD oil. Tried Lucas Syn 15W but thought the ride was a little too harsh. JMHO

 

if and when you get tired of front end maintenance, and other related issues, you might want to switch to the progressive monotubes. far superior shock, with no more oil services and no brake dive and a much improved ride, just a thought.