Whatever 'spinning out means', I 'spun out' about half an hour ago. I was running a 42x15 on my main ride which is what I am used to, and a 40x15 on my winter beater (which I was riding today). I changed the 15 cog to a 17 to make it better in the snow and today was the first time I got to give it a real test.
I was headed back home and hit this really steep downhill with pre-rush-hour traffic zooming down it, thinking 'feck' yeah, lets get some spin on!' Boy did I ever. I was passing all the cars cold chillin', but I noticed that the pedals were increasingly pushing my legs, not the other way around, so rather than slowing down, I decided to put more juice onto the pedals to get back control. This only made the problem worse, because I started spinning way faster than I could handle, and all of a sudden -POP- my feet just get ejected right out of my power grips.
So now I'm anything but cold chillin', hurtling down this hill at around 50km/h with my legs stuck out to the side and the cranks fiendishly churning at their own will. If that wasn't bad enough, a car catches up to me, and starts honking like crazy at my ass! Thank sweet little Jesus I didn't let my balls get the best of me when I built my bike up; a front disc brake is all the stopping power a man could ever need.
Moral of the story? I'll probably try to hit the same hill again tomorrow!