[Bike...and Dennis]

You don't say which model you have, but...
...the Interstates have a needle that climbs nearly to the red mark before the fan comes on. When compared to 3 friend's Aspencades, my bike's fan was coming on about the same time as the Aspy's, in the same riding conditions. This was back when all the bikes were new, and their gauges were not showing the bikes to be hot.

 

[Bike...and Dennis]

Silicate free only, mixed 50/50 with distilled water.

The type of antifreeze you are using probably has nothing to do with your current problem unless it turns out to be the water pump. Then, some silicates may have played a part.