Sturmey Archer releases new kick-shift hubs

Many people ride singlespeed bikes for commuting and day-to-day riding because there are fewer things to go wrong than with a derailleur drivetrain, and they like the simplicity.  Now imagine adding a second gear and a brake to your singlespeed, but with no shift or brake cables, no derailleurs, and no exposed brake mechanism.  Sound nice?  What we've described is called a kickback hub, and they haven't been manufactured for many years... Until now!

In the summer of 2010, Sturmey Archer released a new internally geared hub to fill this void.  It's called the S2C, and it contains mechanisms very similar to those found inside a typical three-speed hub, except that there is a special system that shifts the planetary geartrain between two different ratios every time you pedal backwards slightly.  Pedal backwards a little further and with more force, and you're using the coaster brake.  If you're having trouble picturing this, think of a retractable ballpoint pen.  Click to extend, click to retract; It's the same idea. Some people may consider two speeds and a coaster brake a severe limitation, but anyone who has properly maintained a derailleur drivetrain through a few Minnesota winters will immediately see the possibilities.

Technical information and a video are after the jump...




Several manufacturers have produced kick-shift hubs in the past, notably the Fichtel & Sachs Torpedo Duomatic and the Bendix Automatic.  These hubs, long since out of production, are becoming quite difficult to find in good condition, and procuring spare parts can be even harder.  Fortunately, Sturmey Archer saw fit to produce a modern kickback hub to fill this void.


There are three variations of the hub, each with a different model number:

• S2 - aluminum hub shell, no brake
• S2C - aluminum hub shell, coaster brake
• B2C - steel hub shell, coaster brake (I can't think of any reason to make a version with a steel shell)

The S2, S2C, and B2C kickback hubs all use the same gear ratios, and likely contain identical mechanisms other than the brake differences. The overall range is 138%, and the step between the two gears is 38%. The ratios are:

• 1:1 direct drive
• 1.38:1 overdrive

The hub does not include a cog; any traditional three-spline cog will work, such as those used on most Sturmey Archer hubs, all Shimano Nexus and Alfine hubs, and most coaster brake hubs.

Here's a video of the S2C installed on a Moulton MK3 folding bike:





I've got an S2C on my Sekine now (with an X-FDD front hub) and will be reporting back on how things are going once I've logged more than a few tens of miles on the new setup.