Two cogs on coaster hub?
I know it's not uncommon on old SA hubs for people to replace the 1/2" cog with a pair of dished 3/32" cogs and adding a derailleur for stepped gearing. Is this possible on a regular coaster brake hub running a standard 1/2" cog?
Also, is there any reason I'd have trouble shifting between a really small and a really big cog, i.e. 23t and 15t?