Fixed or SS with front derailier

smallfurry, this is exactly what i was thinking about last night when i couldnt sleep, I thought I'd just invented something new, looks like everything has been done before

i''d definitely like to do it one day, got many other things i need to sort out first though unfortunately. Fast gear for commute, spinny gear for off road. Tyres would be a compromise though. Wide knobbly on tarmac ftl

Totally my own idea.

Ahem...http://www.sheldonbrown.com/singlespeed.html

I have set up a couple of mountain bikes with flip-flop hubs, so that I get a singlespeed on one side and two different freewheel gears on the other. This is done with a double chainwheel and a two-speed freewheel. (The freewheel is actually an old 5- or 6-speed freewheel with 3 of the sprockets replaced by spacers. In front, I have a 42/52 double, which I use with a 19 tooth fixed and a 20/30 freewheel. This gives 3 usable combinations: Gain Inches Meters
52/19 Fixed 5.45 71.2 5.70 General road use
52/20 Free 4.90 64.1 5.13 Road...when I'm tired, or hilly areas.
42/30 Free 2.64 34.4 2.75 Off-road.