SRAM is introducing a two-speed auto-shift internal gear hub to the European market this summer. It’s my understanding that the internal shifting mechanism is controlled by centrifugal force; when you reach a certain speed the hub automatically shifts to a higher gear, and when you slow down, it automatically shifts down (the shifting points can be preset at 7.5, 8.7 or 11.2 mph). Specs as follows:
- Speeds: 2
- Gear Ratios: 1:1 and 1:1,37 = 124%
- Spoke Holes: 28 or 36
- Sprockets: 15, 16, 17, 18, 19, 20, 21
- Finish: Ni-Chrome-plated
- Weight: 980 gr
- Shifting points: 7.5, 8.7 or 11.2 mph
- Brake: Coaster
Automatic shifting is nothing new. From what I can discern, this hub is based upon the rare Sachs Torpedo-Automatic. Then there was Shimano’s ill-fated 3-speed auto-shift “Coasting” drivetrain. And though it’s not exactly an automatic, Sturmey Archer seems to be doing well with their 2-speed kick-shift hub.
I’m not convinced we really need automatic shifting on bikes when we already have indexed internal gear hubs, but for those who want the simplicity and clean lines of a single speed while needing the advantages of a second gear, this is an interesting alternative.
There’s no word yet on price or whether it will be imported into the U.S. The Automatix is the first among other new IGHs from SRAM due out later this year.
View the Spec Sheet [PDF] →
[Hat tip to Jeff L. —ed.]