Originally Posted by
Sianelle
Anybody tried fitting up a pair of cogs to an internal hub and arranging a derailleur to give the hub a Hi-Lo range? When I was using one of my SA 3 speed wheels for some experimental trials with a bike I kept two different sizes of cog on the hub just so I wouldn't lose the one that I wasn't using. It wasn't until later when I was putting the wheel away that I looked at the two cogs and had one of those 'Hey, what the......' moments.
Cyclo used to market just the thing from the late fifties until the late eighties. You'd buy a two, or three speed set of cogs that just replaced standard SA cog, added a rear derailleur and hey presto, instant six or nine speed. The conversion cogs come up now and then on ebay, but are pricey.
I'm also sure that the late Sheldon Brown did something like this. Forum member Sixty Fiver has recently made up a Hi-Lo conversion on an AW for a Phillips Twenty he has set up as a grocery bike.
BTW Sram, formerly Sachs, do a similar hub called the dual drive (or 3x7). It is a wide ratio three speed internally geared hub that instead of a single cog, has a 7, 8 or 9 speed cassette on it. It is usefull on small wheeled bikes such as folders, and on recumbents where putting a front derailleur can be problematic but you still want a wide range of gears.