Here in England many men still use fixed gears for hill climb events. I prefer them if the hill to be attacked is even of angle and not prone to flat spots. Most old-time hillers prefer single fixed and come to events with different chain and gear systems particular to the task that day. The reason for fixed is to save weight only. I ride a 52X15 on grades under 7 degrees and reduce teeth up front from there. Some of our climbs go up to 17 degrees. You see rings in the mid forties for those. And you see hurl in the lane, too.