Fixie vs Road Bike - the right fixie bike for bunch rides At our local bunch rides, we're seeing more and more guys out on fixies and they are going at a phenomenal pace. We have a local segment called the "Chicken Run" (and it's flat) and this one guy in an orange fixie went over 55km/h!

We've spent thousands on our own bikes (carbon, alloy, etc) to have a guy on a simple, light weight fixie / single speed bike beat us like that!?

So my question is - what fixie set up have you got that gives you the "edge in the bunch"? Any specifications to aim for?

At this rate, I am going to have to sell all my bikes for THE ONE fixie.

UPDATE

Yes I know the "engine" (ie: legs) is what counts, but I am after specific gear ratios that could (note I said could) allow you, with reasonable fitness (I am 173cm and in my mid 40s and consider myself fit to very fit) to be able to clock over 50k/hr on the above short 500m segment (my personal record is 43secs and I want to aim for under 40secs).

UPDATE 2

Incidentally, the KOM for that segment has been flagged as it was done by slip-streaming a motorised vehicle.

UPDATE 3

The guy on the orange fixie is Alan Dudderidge who competed in the World Masters last year in Auckland. He is rated 3rd in the world over three events which makes him a top level performer. And it makes my question somewhat useless. :( But still it does show the true engine in any cycling is YOU.
Disclaimer: I am a fixie hater. I'll try to answer this as if I was impartial.

Proper road bikes (Including the Moulton) are the machines for speed, and always have been (unless you're on a velodrome).

Looking at it through a speed lens, a fixie has a slight weight, aero, and drivetrain efficiency advantage over a road bike, but this usually doesn't come anywhere close to offsetting the disadvantages...

It does not have the top end speed and can't accelerate like a road bike because of the gearing. It is horribly inefficient at climbing. If you're hardcore and you ride with no brakes, you have to ride more conservatively because of your poor stopping ability.

On long rides, you will find yourself tiring sooner because you won't be able to ride at your optimal cadence.

The guy on the orange fixie has good legs. He would have been just as fast (if not faster) on a road bike.

Whatever you do, don't "sell all your bikes for THE ONE fixie".