OK, i hit 25mph going down a hill on the way home tonight, pedaling like mad, winter layers, backpack, etc. I found out that my singlespeed Redline 925 is a 42/16 gear thing. When I was going ape-$hit down that hill, I totally reached the point where if I had gears I could have upshifted and gone even faster. Oh well, that's the trade-off for simplicity.