[famousactress]

Other commenters already mentioned the limited amount of pieces to break or maintain (a big plus). Other benefits:

1. The amount of waste between your legs and the road is supremely limited. Until you've been on (evan a cheap) fixed gear you really haven't felt how much power gets lost in a bike with a de-railer setup. It's very addicting.

2. Weight. Sort of related to above.. The truth is, I like climbing most hills on my fixed better than on my geared bike because it's so light. Gears are nice, but there's no substitute for just plain doing less work.

[jrockway]

You can build light fixed-gear bikes, but most fixed-gear bikes you buy at a store are going to be heavier than a racing bike from the same store. Of course, the price difference is going to be $3000, so perhaps that doesn't matter much. I have a steel single/fixed bike for commuting and a carbon-fiber racing bike, and the racing bike is about 7 pounds lighter than the fixed-gear bike. (I do have some bells and whistles on the commuting bike that add weight, like a chainguard, fenders, and a rack; but those only add about a pound or so.)

I'm going to try to build a sub-15-pound fixed-gear bike in the near future, so we'll see how that goes. The reason you see so many 15-pound derailer bikes is because 14.99 pounds is the lower limit for UCI races, and the people that spend money on light bikes are doing that to ride them in UCI races.

As for wasted power; I picked a gear that matches my fixed gear bike's gear and rode both for a mile at a 95rpm cadence. Same heart rate both times, which means my body is working equally hard to propel both the same distance and speed. Pushing your sail-like body through the air is where your energy goes when riding a bike. Everything else is a rounding error.

(It would be nice if someone with power-measuring pedals and a power-measuring hub could try both scenarios, though. Then you would know exactly how many watts are being lost in the drivetrain.)

[famousactress]

Sorry.. yeah, I was comparing relatively comparable budgets (or frankly even fixed budget N vs geared budget N*2).

As far as the wasted power, so again.. I don't have a 3k road bike. Both my bikes cost < 700$ to put together, and at that price the fixed gear is probably gonna be lots more efficient :) I wouldn't be surprised to find out that the power loss might be somewhat psychological either. Might be the feeling of the pedals pushing you in the soft parts of the stroke that in-part make you feel that connected with the pavement... either way, it feels good. Probly as good as a few hundred bucks for a bicycle can feel :)

[Edit: Oh! Forgot another thing I really like about fixed's.. Silence! Admittedly, bit of icing on the cake more than a core reason for riding.. but the complete lack of sound that comes from a fixed can be a pretty beautiful thing when riding early morning or late at night (when there's not a bunch of other noise to drown out freewheel clicking anyways)]

[jrockway]

Honestly, cheap bike components aren't inefficient, they just wear out very quickly. Low-end components use plastic where high-end components use metal, and really high-end components use titanium instead of aluminum.

In my opinion, cheap components look and feel ugly regardless of what kind of bike they are attached to. The good news is that you can build a fixed gear bike out of good equipment for what you'd pay for a racing bike groupset.