Detonation is the spontaneous combustion of the end-gas (remaining fuel/air mixture) in the chamber. It always occurs after normal combustion is initiated by the spark plug. The initial combustion at the spark plug is followed by a normal combustion burn. For some reason, likely heat and pressure, the end gas in the chamber spontaneously combusts. The key point here is that detonation occurs after you have initiated the normal combustion with the spark plug.

I'm lazy today so I did a cut and paste for you.
Essentially, you have two flame fronts burning tward each other. They run into each other and cause the ping you hear.

High(er) octane gasoline done ignite as easy as the cheap stuff. So your only flame front is the one started by the sparkplug.

<div class="FTQUOTE"><begin quote>If I am correct it is a simple octane issue, as suggested, I could have gotten some flat gas, but I think for future rides I will run a mix (gallon of 110 and 4 93 pump) and see what happens. Can't hurt anything. </end quote></div>
This would be a very good thing to do and will tell you a lot. I really don't think you have a detonation problem, but I would not bet my life on it A lot of things can make an engine detonate.

If you still hear the "ping" with the race gas in it you will know for sure it is something else.

Let us know what you find out.