[mydlyfkryzis]

I run straight 50 weight HD oil in the heat here in Florida

Most HD's are designed for and recommend 50 weight oil.

Most air cooled bikes rely on oil for cooling internal surfaces. Putting in heavier weight oil increases pressure, but reduces flow volume. Oil galleries have orifices and passages designed to balance the flow rate to the right parts when using designed weight oil. When you use a much thinner or thicker oil, the oil does not flow to the right places in the right amount. In an emergency of some sort, you can put a different than spec'ed oil, but change it.

As was said, if you don't ride when it is below 20 degrees out, the "W" (For Winter) oil is not too relevant.

Shell Rotella T6 is a great synthetic oil. It is JASO MA1 and MA2 rated, is inexpensive compared to others (Walmart sells it). I use the 5W-40 on my 91 CB750 and my CB360. Clutches work great and no other problems. My BMW uses 15W-50, which I thought was odd, but I stay with that as that is what the engine, oil orifices, oil pump, etc are made for.