I'm aware that several gearing threads have been started in the past, but I just have a question regarding a huge disconnect between what I read online and these forums, and what the bike shop expert says.
So I have the rare luxury of having a bike shop whose owner is a mad genius of bikes, and does pretty much everything, fixed-gear/track related or otherwise. I had him build me up a pair of wheels and set up the chainline on my frame, and he did a super job.
However, he personally thinks that any gear higher than 61-63 inches is crazy. He says that 1) anything higher will destroy your knees and 2) riding anything higher defeats the purpose of fixed gear, whose most important challenge is that you should indeed spin out at high RPM to achieve cruising speed, and that only by mastering the "spinout" you improve your legs and spin.
This forum's fixed gear members don't seem to want to touch anything lower than 68-70 inches, and some of them ride insanely high gears, in the 80s.
So i dunno, what are your opinons on this? I'm getting a 16-tooth cog on Wednesday to replace my current 18T, to get a 42x16 gear (~68 inches) instead of my current 42x18 (~62 inches). I know the 16T will fit me better, since I constantly spin out in order to rich sub-cruising speeds like 17-18 mph. But will it defeat the "purpose of riding fixed?"