I was pootling along Exmouth seafront yesterday at about 10-15 mph, following a line of cars. I noticed that the temp was climbing rapidly, even though I didn't actually stop. Then when I went round the roundabout at the far end and came back the other way at the same sort of speed, the temp went back down just as rapidly. Took me a few moments to realise what was going on. Can anyone else work it out I wonder??
It's all about apparent wind. When I was going down the seafront at 10-15 mph, I had a following wind of 10-15 mph, so zero airflow through the radiator. When I turned round, I had a headwind of 10-15 mph added to the bikes speed over the ground of 10-15 mph, giving 20-30 mph of flow through the radiator.
Proof that if there were fewer cars on the road and more bikes pootling would be unnecessary, engines would run cooler and the planet would last longer. Buy a bike, ride fast and save the planet.
I wasn't suggesting the 'optimum speed' (for fuel economy) was a fixed number. It would vary according to several factors, as you rightly say.
Not in Florida, it doesn't. No hills in Florida. Actually, there is nothing in Florida. Not. A. Thing.
The faster you go, the more fun you have and the less time you spend in a car, so less fuel is used per lifetime = a greener world. Ride fast, ride often, save the planet. :Woot: