both of my sons own fixies. My older son got one because he hates dealing with changing gears. his is geared low. My younger son is very strong and has HIS fixie geared high (so he can ride much faster, or slower with a lower cadence) I think he has his more for street cred, as he also has a road bike with multiple gears.

I honestly had that same question in mind when i read the ride report of a friend of mine who just finished a 300 kilometer Randonneur ride on a fixie. He finished the ride with barely minutes to spare... 19 hours and 58 minutes. The cut off was 20 hours. Most people were in bed long long before that. I will share with you a part of his ride report:

"I drank some hot cocoa and ate some banana bread, then I was off! It was ~12:30 a.m. and I needed to cover 28 miles by 3:00 a.m. It was, indeed, a fairly decent tail wind. I realized I could still make the 20 hour time limit, if I stayed steady. But, after a while I was struggling to stay awake. This didn't help my speed.

I struggled on, occasionally dozing off, occasionally being awakened by having drifted onto the rumble strips. Then I'd try to pick up my speed ... until I became drowsy again.

Finally I saw the lights of Sedro Wooley. Now I smelled the barn and no longer struggled to fight off falling asleep."