not at all scientific test this weekend: -
Method
Ride the same 47 mile loop in similar conditions. Firstly on On-One Pompino running 69" fixed, then geared road bike - other than gears the road bike has 5lbs advantage. Each ride done after resting for a day.
Results
Splits:
First 20 miles, overall downhill couple of steep descents
Fixed: 1:05
Geared: 0:59
20-30, flat
Fixed: 0:33
Geared: 0:29
Last 17 miles, uphill overall including 3 mile climb to finish
Fixed: 1:05
Geared: 0:58
total average speed
Fixed: 17.3
Geared: 19.3
Average/Max HR
Fixed: 139/174 - legs aching
Geared: 144/169 - felt fine
conclusions:
So probably, in this case, fixed was not faster. But then, although I have done a lot of single speed riding in the last couple of years, this was my 5th road ride on fixed and I feel overall time was hampered by difficulty in maintaining speed downhill and legs felt heavy before about 2 hours. I know I can do all the climbs on this route at least as fast/similar effort on single speed as my geared bike. With a few more fixed miles under my belt and riding my lighter fixed bike with a bigger gear then I think there would be less difference.
Summary:
Dunno, bit of one, half dozen of the other.
Thoroughly enjoyed both rides however. That was one of my faster geared rides (at that level of effort anyway) and I have noticed that by mixing between fixed, single speed (on and off road) and geared bikes I seem to be improving my riding when for the last few years of riding just geared bikes performance had been pretty static. I suspect that there's nothing earth shattering in that conclusion.