TL;DR 4:1 ratio is where it's at if you want to use normal pedals, you just need to strengthen up your legs a bit - do some squats at the gym for 6 months and eat healthily. Or "eat healthy" as Americans would say (sorry couldn't resist). Healthy is an adjective not an adverb! Anyway once you're in good shape I wholeheartedly recommend 52/13. Try it and see how it feels. As I said I'm running 52/12 and that's with short cranks as well, so 52/13 with standard (170mm) cranks is no big deal. You can get a 13T 1/8" fixed cog for <$5 on Ebay/Alixpress (from China) and it will last many a year.... at least compared to any 3/32" cog. 12T is a bit rarer and more expensive though. Also the quality of 12T cogs varies much more, expect to pay at least $25 for a good one. And please don't think I'm some kind of Chris Hoy with tree-trunk legs. Not at all, I've just been cycling since childhood and am quite passionate about bikes, that's all. Good luck and may you keep riding fixed! Perhaps forego the higher gearing and get toeclips instead
