big in front, small in back, for your purposes. 49 x 16 is a pretty stout gear for most, but hell, run a 53 x 11 if you only ever go down.
i don't call mine a fixed gear, rather a wrong gear...it's never right. gear for the downs and you walk up. gear for the ups and you've got your problem. gear in between and, well, you get the idea. that's why they make bikes with gears.
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