Re: Interesting video of Sachs Elan disassembly
- View SourceMark;
Thanks for the link.
For those interested the earliest IGH Technical manual available on the SRAM web site has lots of information on the 12 speed hub. It was discontinued shortly after SRAM bought Sachs, apparently due to a combination of reliability issues and minimal sales. Introduction of the Rohloff hub with a wider range at half the weight may have influenced things too.
Overall gear range was about the same as the iM9 but the steps were very tight in the higher gears. Where most IGH designs aim for similar percentage steps through the range the Elan 12 speed was configured to give the effect of a corncob derailleur freewheel, percentage changes between ratios decreased in the higher gears so the gear inches changes between steps were almost linear. An interesting design but very large and heavy, comparable to the NuVinci in that respect.
The spacing of the hub spoke flanges were also such that the wheel using it had a lot of dish and the flanges were very different diameters. Probably a PITA for wheel builders.
--- In Geared_hub_bikes@yahoogroups.com, "Mark Glusker" <glusker@...> wrote:
> I stumbled across this and thought it might be of general interest:
> As I understand it, the technology of this Sachs/SRAM 12-speed hub is the basis for the iMotion 9.