I sold my Gixxer 1K a little while ago, and the buyer asked me what I ran in it.
I handed him a jug of 15w40 diesel oil.
He looked shocked, so I explained it was my choice after much reading.
I also said at first the bike got motorcycle specific 10w40 oil, semi synthethic, and pricey, I got it at the honda dealer.
After about 4 oil changes with that, I switched to conventional oil, 10w40, I noticed no difference.
Then I got talked into going to synthetic, I ran motorcycle specific synthetic 10w40 amsoil, and again noticed no difference, other than slightly notchier shifting, but not a lot worse.
After going to a bike rally, and talking to many riders, and old time wrenchers, they said stop wasting money and use a diesel spec 15w40 oil in regular dino oil.
Ever since all I have used in my last 3 street bikes is Esso delo 15w40 dino, and it works great. In my Gixxer if anything it shifted better on the delo 15w40 than the others, as for the engine, it ran like new when i sold it with 128,000 kms on it.
Time alone with ones thoughts, is quality time.
They say there is a lack of jobs. Seems here to be more a lack of people willing to work hard, and take pride in the work they do.