If you think about derailleur-equipped bicycles, the past 20 years have been notable for many things, the least of which is the addition of cogs to the rear end of the bicycle. Drivetrains have grown from freewheels with five and six cogs to cassettes with seven, eight, nine and ten.
Campy even introduced an 11-cog cassette in 2008. For those who still refer to skinny tired bicycles as “10-speeds,” that’s 11 speeds from the rear derailleur alone. Multiply the rear cogs by two chainrings and you end up with a 22-speed. And if you’re running a triple crank, a 33-speed.
The math, of course, overlooks the fact that many of the gear combinations overlap and that some of the possible chainlines – for instance, from the small chainring up front to the smallest cog in the rear – are inefficient at best and unusable at worst.
Just as unfortunate, as major manufacturers turn out cassettes with more and more cogs, older, simpler designs, like five-cog freewheels, are abandoned to “will-fit” manufacturers.
The story’s a little different for bicycles with internally-geared hubs. Sturmey Archer still makes a three-speed hub that’s similar to the model it introduced in the 1930s.
And while Bendix stopped making two-speed hubs long ago, Sturmey is also making a two-speed kickback hub that I’ve been considering for a future project bike.
Which means today, while you can buy internally-geared hubs with up to 11 gears or, in the case of the NuVinci continuously variable transmission, no distinct gears at all, you can still get a simple two-speed hub.
And soon, you’ll also have your choice of two speeder. SRAM has announced a hub that sounds similar to the old Torpedo Automatic, a limited-production hub from the 1960s that shifted itself, without rider intervention, as the wheel turned faster.
SRAM expects the hub to be popular inside the folding-bike community.