I ride this bike hard and in slow twisty stuff. The fan will not come on so long as you are in second gear and moving. You only need a little speed for the radiators to dump the heat.

When working the bike, I notice waves of heat on my legs. They must correspond with the stat opening and closing since they aren't related to loading.

 

The only time I can get the fan to switch on is by letting it sit there idling in neutral for a very long time! Even on a slow, rocky trail with 100 degF ambient = no fan. The cooling capacity on this bike is huge with the two radiators which is a good thing.

 

Never had a boilover & only ever seen my heat warning light on once & that was because I didn't have the correct ratio of coolant/water after fitting a big bore kit!! At 50/50 ratio have not seen the light come on in over 7000miles.

Temp here in Thailand is always around 30c+(90f+) in the direct sun. My fan around town is on about 20% of the time if riding slowly or sitting at traffic lights for long periods of time.....not a problem

 

100 degrees + first gear + slow single track = Fan........I was told there would be no math. LOL

 

It likely wouldn't have mattered where the sending unit was with no water to measure the temp. An oil temp would be the only real solution then.