Originally Posted by
Monster Pete
The trick with 3-speeds is to get the gearing right. People may assume that you want 2nd to be your level-ground gear, so you have 1st for climbing and 3rd for descending. However, in practice, this results in 3rd gear being uselessly high, and 1st not really being low enough for climbing hills.
It's better to set up the bike such that 3rd gear is your level-ground gear. 1st and 2nd are then usefully placed for acceleration in traffic, climbing hills and combating headwinds. If you spin out going downhill, just coast. Most of your riding will likely be done in 3rd gear- particularly if you ride a single speed at all- with 1st and 2rd as your backup gears.
One thing you do need is to be able to pedal through a wide power band. If you're used to a bike with a 9 or 10-speed derailleur system, you may struggle somewhat with the widely-spaced gears of a 3-speed. However, this capability comes from going out and riding the thing.
Interestingly, the Sturmey-Archer S3X does set top gear as direct drive. I've read elsewhere on the board that it uses the bottom three ratios of the SR5(W) five-speed hub. According to Sheldon Brown's Gear Calculator, it steps .63/.75/1.0, or (rounding) 43/52/69 gear inches with a 46/18 ring and cog and 700x32 tire and 170mm crank arms.
Although the S3X is a a fixed gear hub, it does take a thread on freewheel. From what I've read, it's hit and miss on getting a freewheel cog that will thread on properly. ACS and Dicta are two brands that have at least some models that work. Because of it's range, a factory
freewheel version of the S3X would be an interesting OEM option, but I can't see it happening because the good ol' AW and the Shimano Nexus pretty much define the term "three-speed". As it is, the only two bikes I know of that came standard with the S3X hub were the Felt Broughm and the Mercier Kilo S3X, neither of which is currently available.