Singlespeeded for years, I’ll always be faster with gears. If your faster with single speed its because your not using your gears properly,
I’d have shaved around 10 mins off my mayhem lap times with gears. Nothing to do with the steep climbs but the slight downhill’s which I could have pedalled more and the slight drags uphill which took so much out of my legs.
But I ride single speed because:
I love the simplicity of a single speed and the silence